Merge changes I9494ce71,Idc14e4ad,I30de692e,Ieed3223b,I63d0667a

* changes:
  liblogcat: add android_logcat_popen and android_logcat_system
  liblogcat: add android_logcat_run_command_thread
  logcat: Create liblogcat
  logcat: Use std::string instead of large static buffer for -Q
  logcat: Add coding style

9 files changed, 1594 insertions, 739 deletions

diff --git a/logcat/.clang-format b/logcat/.clang-format
new file mode 100644
index 000000000..393c3094b
--- /dev/null
+++ b/logcat/.clang-format
@@ -0,0 +1,11 @@
+BasedOnStyle: Google
+AllowShortFunctionsOnASingleLine: false
+
+CommentPragmas: NOLINT:.*
+DerivePointerAlignment: false
+IndentWidth: 4
+PointerAlignment: Left
+TabWidth: 4
+PenaltyExcessCharacter: 32
+
+Cpp11BracedListStyle: false
diff --git a/logcat/Android.mk b/logcat/Android.mk
index 1dacbe1ad..5ed0938fd 100644
--- a/logcat/Android.mk
+++ b/logcat/Android.mk
@@ -1,20 +1,32 @@
 # Copyright 2006-2014 The Android Open Source Project
 
-LOCAL_PATH:= $(call my-dir)
-include $(CLEAR_VARS)
+LOCAL_PATH := $(call my-dir)
 
-LOCAL_SRC_FILES:= logcat.cpp event.logtags
+logcatLibs := liblog libbase libcutils libpcrecpp
 
-LOCAL_SHARED_LIBRARIES := liblog libbase libcutils libpcrecpp
+include $(CLEAR_VARS)
 
 LOCAL_MODULE := logcat
-
+LOCAL_SRC_FILES := logcat_main.cpp event.logtags
+LOCAL_SHARED_LIBRARIES := liblogcat $(logcatLibs)
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
 LOCAL_CFLAGS := -Werror
 
 include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)
 
+LOCAL_MODULE := liblogcat
+LOCAL_SRC_FILES := logcat.cpp logcat_system.cpp
+LOCAL_SHARED_LIBRARIES := $(logcatLibs)
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+LOCAL_EXPORT_C_INCLUDES_DIR := $(LOCAL_PATH)/include
+LOCAL_CFLAGS := -Werror
+
+include $(BUILD_SHARED_LIBRARY)
+
+include $(CLEAR_VARS)
+
 LOCAL_MODULE := logpersist.start
 LOCAL_MODULE_TAGS := debug
 LOCAL_MODULE_CLASS := EXECUTABLES
diff --git a/logcat/include/log/logcat.h b/logcat/include/log/logcat.h
new file mode 100644
index 000000000..009672cd5
--- /dev/null
+++ b/logcat/include/log/logcat.h
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2005-2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _LIBS_LOGCAT_H /* header boilerplate */
+#define _LIBS_LOGCAT_H
+
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __ANDROID_USE_LIBLOG_LOGCAT_INTERFACE
+#ifndef __ANDROID_API__
+#define __ANDROID_USE_LIBLOG_LOGCAT_INTERFACE 1
+#elif __ANDROID_API__ > 24 /* > Nougat */
+#define __ANDROID_USE_LIBLOG_LOGCAT_INTERFACE 1
+#else
+#define __ANDROID_USE_LIBLOG_LOGCAT_INTERFACE 0
+#endif
+#endif
+
+#if __ANDROID_USE_LIBLOG_LOGCAT_INTERFACE
+
+/* For managing an in-process logcat function, rather than forking/execing
+ *
+ * It also serves as the basis for the logcat command.
+ *
+ * The following C API allows a logcat instance to be created, run
+ * to completion, and then release all the associated resources.
+ */
+
+/*
+ * The opaque context
+ */
+#ifndef __android_logcat_context_defined /* typedef boilerplate */
+#define __android_logcat_context_defined
+typedef struct android_logcat_context_internal* android_logcat_context;
+#endif
+
+/* Creates a context associated with this logcat instance
+ *
+ * Returns a pointer to the context, or a NULL on error.
+ */
+android_logcat_context create_android_logcat();
+
+/* Collects and outputs the logcat data to output and error file descriptors
+ *
+ * Will block, performed in-thread and in-process
+ *
+ * The output file descriptor variable, if greater than or equal to 0, is
+ * where the output (ie: stdout) will be sent. The file descriptor is closed
+ * on android_logcat_destroy which terminates the instance, or when an -f flag
+ * (output redirect to a file) is present in the command.  The error file
+ * descriptor variable, if greater than or equal to 0, is where the error
+ * stream (ie: stderr) will be sent, also closed on android_logcat_destroy.
+ * The error file descriptor can be set to equal to the output file descriptor,
+ * which will mix output and error stream content, and will defer closure of
+ * the file descriptor on -f flag redirection.  Negative values for the file
+ * descriptors will use stdout and stderr FILE references respectively
+ * internally, and will not close the references as noted above.
+ *
+ * Return value is 0 for success, non-zero for errors.
+ */
+int android_logcat_run_command(android_logcat_context ctx, int output, int error,
+                               int argc, char* const* argv, char* const* envp);
+
+/* Will not block, performed in-process
+ *
+ * Starts a thread, opens a pipe, returns reading end fd, saves off argv.
+ * The command supports 2>&1 (mix content) and 2>/dev/null (drop content) for
+ * scripted error (stderr) redirection.
+ */
+int android_logcat_run_command_thread(android_logcat_context ctx, int argc,
+                                      char* const* argv, char* const* envp);
+int android_logcat_run_command_thread_running(android_logcat_context ctx);
+
+/* Finished with context
+ *
+ * Kill the command thread ASAP (if any), and free up all associated resources.
+ *
+ * Return value is the result of the android_logcat_run_command, or
+ * non-zero for any errors.
+ */
+int android_logcat_destroy(android_logcat_context* ctx);
+
+/* derived helpers */
+
+/*
+ * In-process thread that acts like somewhat like libc-like system and popen
+ * respectively.  Can not handle shell scripting, only pure calls to the
+ * logcat operations. The android_logcat_system is a wrapper for the
+ * create_android_logcat, android_logcat_run_command and android_logcat_destroy
+ * API above.  The android_logcat_popen is a wrapper for the
+ * android_logcat_run_command_thread API above.  The android_logcat_pclose is
+ * a wrapper for a reasonable wait until output has subsided for command
+ * completion, fclose on the FILE pointer and the android_logcat_destroy API.
+ */
+int android_logcat_system(const char* command);
+FILE* android_logcat_popen(android_logcat_context* ctx, const char* command);
+int android_logcat_pclose(android_logcat_context* ctx, FILE* output);
+
+#endif /* __ANDROID_USE_LIBLOG_LOGCAT_INTERFACE */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _LIBS_LOGCAT_H */
diff --git a/logcat/logcat.cpp b/logcat/logcat.cpp
index 4a171fdc8..15cef1ac2 100644
--- a/logcat/logcat.cpp
+++ b/logcat/logcat.cpp
@@ -1,4 +1,18 @@
-// Copyright 2006-2015 The Android Open Source Project
+/*
+ * Copyright (C) 2006-2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 
 #include <arpa/inet.h>
 #include <assert.h>
@@ -8,8 +22,8 @@
 #include <fcntl.h>
 #include <getopt.h>
 #include <math.h>
+#include <pthread.h>
 #include <sched.h>
-#include <signal.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -22,8 +36,10 @@
 #include <time.h>
 #include <unistd.h>
 
+#include <atomic>
 #include <memory>
 #include <string>
+#include <vector>
 
 #include <android-base/file.h>
 #include <android-base/stringprintf.h>
@@ -31,6 +47,7 @@
 #include <cutils/sched_policy.h>
 #include <cutils/sockets.h>
 #include <log/event_tag_map.h>
+#include <log/logcat.h>
 #include <log/logprint.h>
 #include <private/android_logger.h>
 #include <system/thread_defs.h>
@@ -39,16 +56,82 @@
 
 #define DEFAULT_MAX_ROTATED_LOGS 4
 
-static AndroidLogFormat * g_logformat;
+struct android_logcat_context_internal {
+    // status
+    volatile std::atomic_int retval;  // valid if thread_stopped set
+    // Arguments passed in, or copies and storage thereof if a thread.
+    int argc;
+    char* const* argv;
+    char* const* envp;
+    std::vector<std::string> args;
+    std::vector<const char*> argv_hold;
+    std::vector<std::string> envs;
+    std::vector<const char*> envp_hold;
+    int output_fd;
+    int error_fd;
+
+    // library
+    int fds[2];    // From popen call
+    FILE* output;  // everything writes to fileno(output), buffer unused
+    FILE* error;   // unless error == output.
+    pthread_t thr;
+    volatile std::atomic_bool stop;  // quick exit flag
+    volatile std::atomic_bool thread_stopped;
+    bool stderr_null;    // shell "2>/dev/null"
+    bool stderr_stdout;  // shell "2>&1"
+
+    // global variables
+    AndroidLogFormat* logformat;
+    const char* outputFileName;
+    // 0 means "no log rotation"
+    size_t logRotateSizeKBytes;
+    // 0 means "unbounded"
+    size_t maxRotatedLogs;
+    size_t outByteCount;
+    int printBinary;
+    int devCount;  // >1 means multiple
+    pcrecpp::RE* regex;
+    // 0 means "infinite"
+    size_t maxCount;
+    size_t printCount;
+    bool printItAnyways;
+    bool debug;
+
+    // static variables
+    bool hasOpenedEventTagMap;
+    EventTagMap* eventTagMap;
+};
+
+// Creates a context associated with this logcat instance
+android_logcat_context create_android_logcat() {
+    android_logcat_context_internal* context;
+
+    context = (android_logcat_context_internal*)calloc(
+        1, sizeof(android_logcat_context_internal));
+    if (!context) return NULL;
+
+    context->fds[0] = -1;
+    context->fds[1] = -1;
+    context->output_fd = -1;
+    context->error_fd = -1;
+    context->maxRotatedLogs = DEFAULT_MAX_ROTATED_LOGS;
+
+    context->argv_hold.clear();
+    context->args.clear();
+    context->envp_hold.clear();
+    context->envs.clear();
+
+    return (android_logcat_context)context;
+}
 
-/* logd prefixes records with a length field */
+// logd prefixes records with a length field
 #define RECORD_LENGTH_FIELD_SIZE_BYTES sizeof(uint32_t)
 
 struct log_device_t {
     const char* device;
     bool binary;
-    struct logger *logger;
-    struct logger_list *logger_list;
+    struct logger* logger;
+    struct logger_list* logger_list;
     bool printed;
 
     log_device_t* next;
@@ -65,64 +148,121 @@ struct log_device_t {
 
 namespace android {
 
-/* Global Variables */
-
-static const char * g_outputFileName;
-// 0 means "no log rotation"
-static size_t g_logRotateSizeKBytes;
-// 0 means "unbounded"
-static size_t g_maxRotatedLogs = DEFAULT_MAX_ROTATED_LOGS;
-static int g_outFD = -1;
-static size_t g_outByteCount;
-static int g_printBinary;
-static int g_devCount;                              // >1 means multiple
-static pcrecpp::RE* g_regex;
-// 0 means "infinite"
-static size_t g_maxCount;
-static size_t g_printCount;
-static bool g_printItAnyways;
-static bool g_debug;
-
-enum helpType {
-    HELP_FALSE,
-    HELP_TRUE,
-    HELP_FORMAT
-};
+enum helpType { HELP_FALSE, HELP_TRUE, HELP_FORMAT };
 
 // if showHelp is set, newline required in fmt statement to transition to usage
-__noreturn static void logcat_panic(enum helpType showHelp, const char *fmt, ...) __printflike(2,3);
+static void logcat_panic(android_logcat_context_internal* context,
+                         enum helpType showHelp, const char* fmt, ...)
+    __printflike(3, 4);
 
-static int openLogFile (const char *pathname)
-{
+static int openLogFile(const char* pathname) {
     return open(pathname, O_WRONLY | O_APPEND | O_CREAT, S_IRUSR | S_IWUSR);
 }
 
-static void rotateLogs()
-{
+static void close_output(android_logcat_context_internal* context) {
+    // split output_from_error
+    if (context->error == context->output) {
+        context->output = NULL;
+        context->output_fd = -1;
+    }
+    if (context->error && (context->output_fd == fileno(context->error))) {
+        context->output_fd = -1;
+    }
+    if (context->output_fd == context->error_fd) {
+        context->output_fd = -1;
+    }
+    // close output channel
+    if (context->output) {
+        if (context->output != stdout) {
+            if (context->output_fd == fileno(context->output)) {
+                context->output_fd = -1;
+            }
+            if (context->fds[1] == fileno(context->output)) {
+                context->fds[1] = -1;
+            }
+            fclose(context->output);
+        }
+        context->output = NULL;
+    }
+    if (context->output_fd >= 0) {
+        if (context->output_fd != fileno(stdout)) {
+            if (context->fds[1] == context->output_fd) {
+                context->fds[1] = -1;
+            }
+            close(context->output_fd);
+        }
+        context->output_fd = -1;
+    }
+}
+
+static void close_error(android_logcat_context_internal* context) {
+    // split error_from_output
+    if (context->output == context->error) {
+        context->error = NULL;
+        context->error_fd = -1;
+    }
+    if (context->output && (context->error_fd == fileno(context->output))) {
+        context->error_fd = -1;
+    }
+    if (context->error_fd == context->output_fd) {
+        context->error_fd = -1;
+    }
+    // close error channel
+    if (context->error) {
+        if ((context->error != stderr) && (context->error != stdout)) {
+            if (context->error_fd == fileno(context->error)) {
+                context->error_fd = -1;
+            }
+            if (context->fds[1] == fileno(context->error)) {
+                context->fds[1] = -1;
+            }
+            fclose(context->error);
+        }
+        context->error = NULL;
+    }
+    if (context->error_fd >= 0) {
+        if ((context->error_fd != fileno(stdout)) &&
+            (context->error_fd != fileno(stderr))) {
+            if (context->fds[1] == context->error_fd) {
+                context->fds[1] = -1;
+            }
+            close(context->error_fd);
+        }
+        context->error_fd = -1;
+    }
+}
+
+static void rotateLogs(android_logcat_context_internal* context) {
     int err;
 
     // Can't rotate logs if we're not outputting to a file
-    if (g_outputFileName == NULL) {
+    if (context->outputFileName == NULL) {
         return;
     }
 
-    close(g_outFD);
+    close_output(context);
 
-    // Compute the maximum number of digits needed to count up to g_maxRotatedLogs in decimal.
-    // eg: g_maxRotatedLogs == 30 -> log10(30) == 1.477 -> maxRotationCountDigits == 2
+    // Compute the maximum number of digits needed to count up to
+    // maxRotatedLogs in decimal.  eg:
+    // maxRotatedLogs == 30
+    //   -> log10(30) == 1.477
+    //   -> maxRotationCountDigits == 2
     int maxRotationCountDigits =
-            (g_maxRotatedLogs > 0) ? (int) (floor(log10(g_maxRotatedLogs) + 1)) : 0;
+        (context->maxRotatedLogs > 0)
+            ? (int)(floor(log10(context->maxRotatedLogs) + 1))
+            : 0;
 
-    for (int i = g_maxRotatedLogs ; i > 0 ; i--) {
+    for (int i = context->maxRotatedLogs; i > 0; i--) {
         std::string file1 = android::base::StringPrintf(
-            "%s.%.*d", g_outputFileName, maxRotationCountDigits, i);
+            "%s.%.*d", context->outputFileName, maxRotationCountDigits, i);
 
         std::string file0;
         if (i - 1 == 0) {
-            file0 = android::base::StringPrintf("%s", g_outputFileName);
+            file0 = android::base::StringPrintf("%s", context->outputFileName);
         } else {
-            file0 = android::base::StringPrintf(
-                "%s.%.*d", g_outputFileName, maxRotationCountDigits, i - 1);
+            file0 =
+                android::base::StringPrintf("%s.%.*d", context->outputFileName,
+                                            maxRotationCountDigits, i - 1);
         }
 
         if ((file0.length() == 0) || (file1.length() == 0)) {
@@ -137,153 +277,160 @@ static void rotateLogs()
         }
     }
 
-    g_outFD = openLogFile(g_outputFileName);
+    context->output_fd = openLogFile(context->outputFileName);
 
-    if (g_outFD < 0) {
-        logcat_panic(HELP_FALSE, "couldn't open output file");
+    if (context->output_fd < 0) {
+        logcat_panic(context, HELP_FALSE, "couldn't open output file");
+        return;
     }
+    context->output = fdopen(context->output_fd, "web");
 
-    g_outByteCount = 0;
-
+    context->outByteCount = 0;
 }
 
-void printBinary(struct log_msg *buf)
-{
+void printBinary(android_logcat_context_internal* context, struct log_msg* buf) {
     size_t size = buf->len();
 
-    TEMP_FAILURE_RETRY(write(g_outFD, buf, size));
+    TEMP_FAILURE_RETRY(write(context->output_fd, buf, size));
 }
 
-static bool regexOk(const AndroidLogEntry& entry)
-{
-    if (!g_regex) {
+static bool regexOk(android_logcat_context_internal* context,
+                    const AndroidLogEntry& entry) {
+    if (!context->regex) {
         return true;
     }
 
     std::string messageString(entry.message, entry.messageLen);
 
-    return g_regex->PartialMatch(messageString);
+    return context->regex->PartialMatch(messageString);
 }
 
-static void processBuffer(log_device_t* dev, struct log_msg *buf)
-{
+static void processBuffer(android_logcat_context_internal* context,
+                          log_device_t* dev, struct log_msg* buf) {
     int bytesWritten = 0;
     int err;
     AndroidLogEntry entry;
     char binaryMsgBuf[1024];
 
     if (dev->binary) {
-        static bool hasOpenedEventTagMap = false;
-        static EventTagMap *eventTagMap = NULL;
-
-        if (!eventTagMap && !hasOpenedEventTagMap) {
-            eventTagMap = android_openEventTagMap(NULL);
-            hasOpenedEventTagMap = true;
+        if (!context->eventTagMap && !context->hasOpenedEventTagMap) {
+            context->eventTagMap = android_openEventTagMap(NULL);
+            context->hasOpenedEventTagMap = true;
         }
-        err = android_log_processBinaryLogBuffer(&buf->entry_v1, &entry,
-                                                 eventTagMap,
-                                                 binaryMsgBuf,
-                                                 sizeof(binaryMsgBuf));
-        //printf(">>> pri=%d len=%d msg='%s'\n",
+        err = android_log_processBinaryLogBuffer(
+            &buf->entry_v1, &entry, context->eventTagMap, binaryMsgBuf,
+            sizeof(binaryMsgBuf));
+        // printf(">>> pri=%d len=%d msg='%s'\n",
         //    entry.priority, entry.messageLen, entry.message);
     } else {
         err = android_log_processLogBuffer(&buf->entry_v1, &entry);
     }
-    if ((err < 0) && !g_debug) {
-        goto error;
+    if ((err < 0) && !context->debug) {
+        return;
     }
 
-    if (android_log_shouldPrintLine(g_logformat,
-                                    std::string(entry.tag, entry.tagLen).c_str(),
-                                    entry.priority)) {
-        bool match = regexOk(entry);
+    if (android_log_shouldPrintLine(
+            context->logformat, std::string(entry.tag, entry.tagLen).c_str(),
+            entry.priority)) {
+        bool match = regexOk(context, entry);
 
-        g_printCount += match;
-        if (match || g_printItAnyways) {
-            bytesWritten = android_log_printLogLine(g_logformat, g_outFD, &entry);
+        context->printCount += match;
+        if (match || context->printItAnyways) {
+            bytesWritten = android_log_printLogLine(context->logformat,
+                                                    context->output_fd, &entry);
 
             if (bytesWritten < 0) {
-                logcat_panic(HELP_FALSE, "output error");
+                logcat_panic(context, HELP_FALSE, "output error");
+                return;
             }
         }
     }
 
-    g_outByteCount += bytesWritten;
+    context->outByteCount += bytesWritten;
 
-    if (g_logRotateSizeKBytes > 0
-        && (g_outByteCount / 1024) >= g_logRotateSizeKBytes
-    ) {
-        rotateLogs();
+    if (context->logRotateSizeKBytes > 0 &&
+        (context->outByteCount / 1024) >= context->logRotateSizeKBytes) {
+        rotateLogs(context);
     }
-
-error:
-    return;
 }
 
-static void maybePrintStart(log_device_t* dev, bool printDividers) {
+static void maybePrintStart(android_logcat_context_internal* context,
+                            log_device_t* dev, bool printDividers) {
     if (!dev->printed || printDividers) {
-        if (g_devCount > 1 && !g_printBinary) {
+        if (context->devCount > 1 && !context->printBinary) {
             char buf[1024];
             snprintf(buf, sizeof(buf), "--------- %s %s\n",
-                     dev->printed ? "switch to" : "beginning of",
-                     dev->device);
-            if (write(g_outFD, buf, strlen(buf)) < 0) {
-                logcat_panic(HELP_FALSE, "output error");
+                     dev->printed ? "switch to" : "beginning of", dev->device);
+            if (write(context->output_fd, buf, strlen(buf)) < 0) {
+                logcat_panic(context, HELP_FALSE, "output error");
+                return;
             }
         }
         dev->printed = true;
     }
 }
 
-static void setupOutputAndSchedulingPolicy(bool blocking) {
-    if (g_outputFileName == NULL) {
-        g_outFD = STDOUT_FILENO;
-        return;
-    }
+static void setupOutputAndSchedulingPolicy(
+    android_logcat_context_internal* context, bool blocking) {
+    if (context->outputFileName == NULL) return;
 
     if (blocking) {
         // Lower priority and set to batch scheduling if we are saving
         // the logs into files and taking continuous content.
-        if (set_sched_policy(0, SP_BACKGROUND) < 0) {
-            fprintf(stderr, "failed to set background scheduling policy\n");
+        if ((set_sched_policy(0, SP_BACKGROUND) < 0) && context->error) {
+            fprintf(context->error,
+                    "failed to set background scheduling policy\n");
         }
 
         struct sched_param param;
         memset(&param, 0, sizeof(param));
-        if (sched_setscheduler((pid_t) 0, SCHED_BATCH, &param) < 0) {
+        if (sched_setscheduler((pid_t)0, SCHED_BATCH, &param) < 0) {
             fprintf(stderr, "failed to set to batch scheduler\n");
         }
 
-        if (setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_BACKGROUND) < 0) {
-            fprintf(stderr, "failed set to priority\n");
+        if ((setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_BACKGROUND) < 0) &&
+            context->error) {
+            fprintf(context->error, "failed set to priority\n");
         }
     }
 
-    g_outFD = openLogFile (g_outputFileName);
+    close_output(context);
+
+    context->output_fd = openLogFile(context->outputFileName);
 
-    if (g_outFD < 0) {
-        logcat_panic(HELP_FALSE, "couldn't open output file");
+    if (context->output_fd < 0) {
+        logcat_panic(context, HELP_FALSE, "couldn't open output file");
+        return;
     }
 
     struct stat statbuf;
-    if (fstat(g_outFD, &statbuf) == -1) {
-        close(g_outFD);
-        logcat_panic(HELP_FALSE, "couldn't get output file stat\n");
+    if (fstat(context->output_fd, &statbuf) == -1) {
+        close_output(context);
+        logcat_panic(context, HELP_FALSE, "couldn't get output file stat\n");
+        return;
     }
 
-    if ((size_t) statbuf.st_size > SIZE_MAX || statbuf.st_size < 0) {
-        close(g_outFD);
-        logcat_panic(HELP_FALSE, "invalid output file stat\n");
+    if ((size_t)statbuf.st_size > SIZE_MAX || statbuf.st_size < 0) {
+        close_output(context);
+        logcat_panic(context, HELP_FALSE, "invalid output file stat\n");
+        return;
     }
 
-    g_outByteCount = statbuf.st_size;
+    context->output = fdopen(context->output_fd, "web");
+
+    context->outByteCount = statbuf.st_size;
 }
 
-static void show_help(const char *cmd)
-{
-    fprintf(stderr,"Usage: %s [options] [filterspecs]\n", cmd);
+// clang-format off
+static void show_help(android_logcat_context_internal* context) {
+    if (!context->error) return;
+
+    const char* cmd = strrchr(context->argv[0], '/');
+    cmd = cmd ? cmd + 1 : context->argv[0];
 
-    fprintf(stderr, "options include:\n"
+    fprintf(context->error, "Usage: %s [options] [filterspecs]\n", cmd);
+
+    fprintf(context->error, "options include:\n"
                     "  -s              Set default filter to silent. Equivalent to filterspec '*:S'\n"
                     "  -f <file>, --file=<file>               Log to file. Default is stdout\n"
                     "  -r <kbytes>, --rotate-kbytes=<kbytes>\n"
@@ -347,7 +494,7 @@ static void show_help(const char *cmd)
                     "                  comes first. Improves efficiency of polling by providing\n"
                     "                  an about-to-wrap wakeup.\n");
 
-    fprintf(stderr,"\nfilterspecs are a series of \n"
+    fprintf(context->error, "\nfilterspecs are a series of \n"
                    "  <tag>[:priority]\n\n"
                    "where <tag> is a log component tag (or * for all) and priority is:\n"
                    "  V    Verbose (default for <tag>)\n"
@@ -365,9 +512,9 @@ static void show_help(const char *cmd)
                    "or defaults to \"threadtime\"\n\n");
 }
 
-static void show_format_help()
-{
-    fprintf(stderr,
+static void show_format_help(android_logcat_context_internal* context) {
+    if (!context->error) return;
+    fprintf(context->error,
         "-v <format>, --format=<format> options:\n"
         "  Sets log print format verb and adverbs, where <format> is:\n"
         "    brief long process raw tag thread threadtime time\n"
@@ -398,10 +545,11 @@ static void show_format_help()
         "  \"<zone>\"    — Print using this public named timezone (experimental).\n\n"
     );
 }
+// clang-format on
 
-static int setLogFormat(const char * formatString)
-{
-    static AndroidLogPrintFormat format;
+static int setLogFormat(android_logcat_context_internal* context,
+                        const char* formatString) {
+    AndroidLogPrintFormat format;
 
     format = android_log_formatFromString(formatString);
 
@@ -410,42 +558,36 @@ static int setLogFormat(const char * formatString)
         return -1;
     }
 
-    return android_log_setPrintFormat(g_logformat, format);
+    return android_log_setPrintFormat(context->logformat, format);
 }
 
-static const char multipliers[][2] = {
-    { "" },
-    { "K" },
-    { "M" },
-    { "G" }
-};
+static const char multipliers[][2] = { { "" }, { "K" }, { "M" }, { "G" } };
 
-static unsigned long value_of_size(unsigned long value)
-{
+static unsigned long value_of_size(unsigned long value) {
     for (unsigned i = 0;
-            (i < sizeof(multipliers)/sizeof(multipliers[0])) && (value >= 1024);
-            value /= 1024, ++i) ;
+         (i < sizeof(multipliers) / sizeof(multipliers[0])) && (value >= 1024);
+         value /= 1024, ++i)
+        ;
     return value;
 }
 
-static const char *multiplier_of_size(unsigned long value)
-{
+static const char* multiplier_of_size(unsigned long value) {
     unsigned i;
     for (i = 0;
-            (i < sizeof(multipliers)/sizeof(multipliers[0])) && (value >= 1024);
-            value /= 1024, ++i) ;
+         (i < sizeof(multipliers) / sizeof(multipliers[0])) && (value >= 1024);
+         value /= 1024, ++i)
+        ;
     return multipliers[i];
 }
 
-/*String to unsigned int, returns -1 if it fails*/
-static bool getSizeTArg(const char *ptr, size_t *val, size_t min = 0,
-                        size_t max = SIZE_MAX)
-{
+// String to unsigned int, returns -1 if it fails
+static bool getSizeTArg(const char* ptr, size_t* val, size_t min = 0,
+                        size_t max = SIZE_MAX) {
     if (!ptr) {
         return false;
     }
 
-    char *endp;
+    char* endp;
     errno = 0;
     size_t ret = (size_t)strtoll(ptr, &endp, 0);
 
@@ -461,31 +603,36 @@ static bool getSizeTArg(const char *ptr, size_t *val, size_t min = 0,
     return true;
 }
 
-static void logcat_panic(enum helpType showHelp, const char *fmt, ...)
-{
-    va_list  args;
+static void logcat_panic(android_logcat_context_internal* context,
+                         enum helpType showHelp, const char* fmt, ...) {
+    context->retval = EXIT_FAILURE;
+    if (!context->error) {
+        context->stop = true;
+        return;
+    }
+
+    va_list args;
     va_start(args, fmt);
-    vfprintf(stderr, fmt,  args);
+    vfprintf(context->error, fmt, args);
     va_end(args);
 
     switch (showHelp) {
-    case HELP_TRUE:
-       show_help(getprogname());
-       break;
-    case HELP_FORMAT:
-       show_format_help();
-       break;
-    case HELP_FALSE:
-    default:
-      break;
-    }
-
-    exit(EXIT_FAILURE);
-}
+        case HELP_TRUE:
+            show_help(context);
+            break;
+        case HELP_FORMAT:
+            show_format_help(context);
+            break;
+        case HELP_FALSE:
+        default:
+            break;
+    }
 
-static char *parseTime(log_time &t, const char *cp) {
+    context->stop = true;
+}
 
-    char *ep = t.strptime(cp, "%m-%d %H:%M:%S.%q");
+static char* parseTime(log_time& t, const char* cp) {
+    char* ep = t.strptime(cp, "%m-%d %H:%M:%S.%q");
     if (ep) {
         return ep;
     }
@@ -497,14 +644,14 @@ static char *parseTime(log_time &t, const char *cp) {
 }
 
 // Find last logged line in <outputFileName>, or <outputFileName>.1
-static log_time lastLogTime(char *outputFileName) {
+static log_time lastLogTime(char* outputFileName) {
     log_time retval(log_time::EPOCH);
     if (!outputFileName) {
         return retval;
     }
 
     std::string directory;
-    char *file = strrchr(outputFileName, '/');
+    char* file = strrchr(outputFileName, '/');
     if (!file) {
         directory = ".";
         file = outputFileName;
@@ -515,8 +662,8 @@ static log_time lastLogTime(char *outputFileName) {
         ++file;
     }
 
-    std::unique_ptr<DIR, int(*)(DIR*)>
-            dir(opendir(directory.c_str()), closedir);
+    std::unique_ptr<DIR, int (*)(DIR*)> dir(opendir(directory.c_str()),
+                                            closedir);
     if (!dir.get()) {
         return retval;
     }
@@ -525,14 +672,12 @@ static log_time lastLogTime(char *outputFileName) {
 
     size_t len = strlen(file);
     log_time modulo(0, NS_PER_SEC);
-    struct dirent *dp;
+    struct dirent* dp;
 
     while ((dp = readdir(dir.get())) != NULL) {
-        if ((dp->d_type != DT_REG) ||
-                (strncmp(dp->d_name, file, len) != 0) ||
-                (dp->d_name[len] &&
-                     ((dp->d_name[len] != '.') ||
-                         (strtoll(dp->d_name + 1, NULL, 10) != 1)))) {
+        if ((dp->d_type != DT_REG) || (strncmp(dp->d_name, file, len) != 0) ||
+            (dp->d_name[len] && ((dp->d_name[len] != '.') ||
+                                 (strtoll(dp->d_name + 1, NULL, 10) != 1)))) {
             continue;
         }
 
@@ -547,7 +692,7 @@ static log_time lastLogTime(char *outputFileName) {
         bool found = false;
         for (const auto& line : android::base::Split(file, "\n")) {
             log_time t(log_time::EPOCH);
-            char *ep = parseTime(t, line.c_str());
+            char* ep = parseTime(t, line.c_str());
             if (!ep || (*ep != ' ')) {
                 continue;
             }
@@ -581,22 +726,30 @@ static log_time lastLogTime(char *outputFileName) {
     return retval;
 }
 
-} /* namespace android */
+const char* getenv(android_logcat_context_internal* context, const char* name) {
+    if (!context->envp || !name || !*name) return NULL;
 
-void reportErrorName(const char **current,
-                     const char* name,
+    for (size_t len = strlen(name), i = 0; context->envp[i]; ++i) {
+        if (strncmp(context->envp[i], name, len)) continue;
+        if (context->envp[i][len] == '=') return &context->envp[i][len + 1];
+    }
+    return NULL;
+}
+
+}  // namespace android
+
+void reportErrorName(const char** current, const char* name,
                      bool blockSecurity) {
     if (*current) {
-       return;
+        return;
     }
     if (blockSecurity && (android_name_to_log_id(name) == LOG_ID_SECURITY)) {
-       return;
+        return;
     }
     *current = name;
 }
 
-int main(int argc, char **argv)
-{
+static int __logcat(android_logcat_context_internal* context) {
     using namespace android;
     int err;
     int hasSetLogFormat = 0;
@@ -607,27 +760,99 @@ int main(int argc, char **argv)
     bool printStatistics = false;
     bool printDividers = false;
     unsigned long setLogSize = 0;
-    char *setPruneList = NULL;
-    char *setId = NULL;
+    char* setPruneList = NULL;
+    char* setId = NULL;
     int mode = ANDROID_LOG_RDONLY;
-    const char *forceFilters = NULL;
+    std::string forceFilters;
     log_device_t* devices = NULL;
     log_device_t* dev;
-    struct logger_list *logger_list;
+    struct logger_list* logger_list;
     size_t tail_lines = 0;
     log_time tail_time(log_time::EPOCH);
     size_t pid = 0;
     bool got_t = false;
 
-    signal(SIGPIPE, exit);
+    // object instantiations before goto's can happen
+    log_device_t unexpected("unexpected", false);
+    const char* openDeviceFail = NULL;
+    const char* clearFail = NULL;
+    const char* setSizeFail = NULL;
+    const char* getSizeFail = NULL;
+    int argc = context->argc;
+    char* const* argv = context->argv;
+
+    context->output = stdout;
+    context->error = stderr;
+
+    for (int i = 0; i < argc; ++i) {
+        // Simulate shell stderr redirect parsing
+        if ((argv[i][0] != '2') || (argv[i][1] != '>')) continue;
+
+        size_t skip = (argv[i][2] == '>') + 2;
+        if (!strcmp(&argv[i][skip], "/dev/null")) {
+            context->stderr_null = true;
+        } else if (!strcmp(&argv[i][skip], "&1")) {
+            context->stderr_stdout = true;
+        } else {
+            // stderr file redirections are not supported
+            fprintf(context->stderr_stdout ? stdout : stderr,
+                    "stderr redirection to file %s unsupported, skipping\n",
+                    &argv[i][skip]);
+        }
+    }
 
-    g_logformat = android_log_format_new();
+    // Deal with setting up file descriptors and FILE pointers
+    if (context->error_fd >= 0) {
+        if (context->error_fd == context->output_fd) {
+            context->stderr_stdout = true;
+        } else if (context->stderr_null) {
+            close(context->error_fd);
+            context->error_fd = -1;
+        } else {
+            context->error = fdopen(context->error_fd, "web");
+            if (!context->error) {
+                context->retval = -errno;
+                fprintf(context->stderr_stdout ? stdout : stderr,
+                        "Failed to fdopen(error_fd=%d) %s\n", context->error_fd,
+                        strerror(errno));
+                goto exit;
+            }
+        }
+    }
+    if (context->output_fd >= 0) {
+        context->output = fdopen(context->output_fd, "web");
+        if (!context->output) {
+            context->retval = -errno;
+            fprintf(context->stderr_stdout ? stdout : context->error,
+                    "Failed to fdopen(output_fd=%d) %s\n", context->output_fd,
+                    strerror(errno));
+            goto exit;
+        }
+    }
+    if (context->stderr_stdout) context->error = context->output;
+    if (context->stderr_null) {
+        context->error_fd = -1;
+        context->error = NULL;
+    }
+    // Only happens if output=stdout
+    if ((context->output_fd < 0) && context->output) {
+        context->output_fd = fileno(context->output);
+    }
+    // Only happens if error=stdout || error=stderr
+    if ((context->error_fd < 0) && context->error) {
+        context->error_fd = fileno(context->error);
+    }
+
+    context->logformat = android_log_format_new();
 
     if (argc == 2 && 0 == strcmp(argv[1], "--help")) {
-        show_help(argv[0]);
-        return EXIT_SUCCESS;
+        show_help(context);
+        context->retval = EXIT_SUCCESS;
+        goto exit;
     }
 
+    // danger: getopt is _not_ reentrant
+    optind = 1;
     for (;;) {
         int ret;
 
@@ -638,6 +863,7 @@ int main(int argc, char **argv)
         static const char id_str[] = "id";
         static const char wrap_str[] = "wrap";
         static const char print_str[] = "print";
+        // clang-format off
         static const struct option long_options[] = {
           { "binary",        no_argument,       NULL,   'B' },
           { "buffer",        required_argument, NULL,   'b' },
@@ -667,9 +893,11 @@ int main(int argc, char **argv)
           { wrap_str,        optional_argument, NULL,   0 },
           { NULL,            0,                 NULL,   0 }
         };
+        // clang-format on
 
-        ret = getopt_long(argc, argv, ":cdDLt:T:gG:sQf:r:n:v:b:BSpP:m:e:",
-                          long_options, &option_index);
+        ret = getopt_long(argc, argv,
+                          ":cdDLt:T:gG:sQf:r:n:v:b:BSpP:m:e:", long_options,
+                          &option_index);
 
         if (ret < 0) {
             break;
@@ -681,23 +909,25 @@ int main(int argc, char **argv)
                 if (long_options[option_index].name == pid_str) {
                     // ToDo: determine runtime PID_MAX?
                     if (!getSizeTArg(optarg, &pid, 1)) {
-                        logcat_panic(HELP_TRUE, "%s %s out of range\n",
+                        logcat_panic(context, HELP_TRUE, "%s %s out of range\n",
                                      long_options[option_index].name, optarg);
+                        goto exit;
                     }
                     break;
                 }
                 if (long_options[option_index].name == wrap_str) {
-                    mode |= ANDROID_LOG_WRAP |
-                            ANDROID_LOG_RDONLY |
+                    mode |= ANDROID_LOG_WRAP | ANDROID_LOG_RDONLY |
                             ANDROID_LOG_NONBLOCK;
                     // ToDo: implement API that supports setting a wrap timeout
                     size_t dummy = ANDROID_LOG_WRAP_DEFAULT_TIMEOUT;
                     if (optarg && !getSizeTArg(optarg, &dummy, 1)) {
-                        logcat_panic(HELP_TRUE, "%s %s out of range\n",
+                        logcat_panic(context, HELP_TRUE, "%s %s out of range\n",
                                      long_options[option_index].name, optarg);
+                        goto exit;
                     }
-                    if (dummy != ANDROID_LOG_WRAP_DEFAULT_TIMEOUT) {
-                        fprintf(stderr,
+                    if ((dummy != ANDROID_LOG_WRAP_DEFAULT_TIMEOUT) &&
+                        context->error) {
+                        fprintf(context->error,
                                 "WARNING: %s %u seconds, ignoring %zu\n",
                                 long_options[option_index].name,
                                 ANDROID_LOG_WRAP_DEFAULT_TIMEOUT, dummy);
@@ -705,154 +935,163 @@ int main(int argc, char **argv)
                     break;
                 }
                 if (long_options[option_index].name == print_str) {
-                    g_printItAnyways = true;
+                    context->printItAnyways = true;
                     break;
                 }
                 if (long_options[option_index].name == debug_str) {
-                    g_debug = true;
+                    context->debug = true;
                     break;
                 }
                 if (long_options[option_index].name == id_str) {
                     setId = optarg && optarg[0] ? optarg : NULL;
                     break;
                 }
-            break;
+                break;
 
             case 's':
                 // default to all silent
-                android_log_addFilterRule(g_logformat, "*:s");
-            break;
+                android_log_addFilterRule(context->logformat, "*:s");
+                break;
 
             case 'c':
                 clearLog = true;
                 mode |= ANDROID_LOG_WRONLY;
-            break;
+                break;
 
             case 'L':
-                mode |= ANDROID_LOG_RDONLY | ANDROID_LOG_PSTORE | ANDROID_LOG_NONBLOCK;
-            break;
+                mode |= ANDROID_LOG_RDONLY | ANDROID_LOG_PSTORE |
+                        ANDROID_LOG_NONBLOCK;
+                break;
 
             case 'd':
                 mode |= ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK;
-            break;
+                break;
 
             case 't':
                 got_t = true;
                 mode |= ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK;
-                /* FALLTHRU */
+            // FALLTHRU
             case 'T':
                 if (strspn(optarg, "0123456789") != strlen(optarg)) {
-                    char *cp = parseTime(tail_time, optarg);
+                    char* cp = parseTime(tail_time, optarg);
                     if (!cp) {
-                        logcat_panic(HELP_FALSE,
-                                     "-%c \"%s\" not in time format\n",
-                                     ret, optarg);
+                        logcat_panic(context, HELP_FALSE,
+                                     "-%c \"%s\" not in time format\n", ret,
+                                     optarg);
+                        goto exit;
                     }
                     if (*cp) {
                         char c = *cp;
                         *cp = '\0';
-                        fprintf(stderr,
+                        if (context->error) {
+                            fprintf(
+                                context->error,
                                 "WARNING: -%c \"%s\"\"%c%s\" time truncated\n",
                                 ret, optarg, c, cp + 1);
+                        }
                         *cp = c;
                     }
                 } else {
                     if (!getSizeTArg(optarg, &tail_lines, 1)) {
-                        fprintf(stderr,
-                                "WARNING: -%c %s invalid, setting to 1\n",
-                                ret, optarg);
+                        if (context->error) {
+                            fprintf(context->error,
+                                    "WARNING: -%c %s invalid, setting to 1\n",
+                                    ret, optarg);
+                        }
                         tail_lines = 1;
                     }
                 }
-            break;
+                break;
 
             case 'D':
                 printDividers = true;
-            break;
+                break;
 
             case 'e':
-                g_regex = new pcrecpp::RE(optarg);
-            break;
+                context->regex = new pcrecpp::RE(optarg);
+                break;
 
             case 'm': {
-                char *end = NULL;
-                if (!getSizeTArg(optarg, &g_maxCount)) {
-                    logcat_panic(HELP_FALSE, "-%c \"%s\" isn't an "
-                                 "integer greater than zero\n", ret, optarg);
+                char* end = NULL;
+                if (!getSizeTArg(optarg, &context->maxCount)) {
+                    logcat_panic(context, HELP_FALSE,
+                                 "-%c \"%s\" isn't an "
+                                 "integer greater than zero\n",
+                                 ret, optarg);
+                    goto exit;
                 }
-            }
-            break;
+            } break;
 
             case 'g':
                 if (!optarg) {
                     getLogSize = true;
                     break;
                 }
-                // FALLTHRU
+            // FALLTHRU
 
             case 'G': {
-                char *cp;
+                char* cp;
                 if (strtoll(optarg, &cp, 0) > 0) {
                     setLogSize = strtoll(optarg, &cp, 0);
                 } else {
                     setLogSize = 0;
                 }
 
-                switch(*cp) {
-                case 'g':
-                case 'G':
-                    setLogSize *= 1024;
-                /* FALLTHRU */
-                case 'm':
-                case 'M':
-                    setLogSize *= 1024;
-                /* FALLTHRU */
-                case 'k':
-                case 'K':
-                    setLogSize *= 1024;
-                /* FALLTHRU */
-                case '\0':
-                break;
+                switch (*cp) {
+                    case 'g':
+                    case 'G':
+                        setLogSize *= 1024;
+                    // FALLTHRU
+                    case 'm':
+                    case 'M':
+                        setLogSize *= 1024;
+                    // FALLTHRU
+                    case 'k':
+                    case 'K':
+                        setLogSize *= 1024;
+                    // FALLTHRU
+                    case '\0':
+                        break;
 
-                default:
-                    setLogSize = 0;
+                    default:
+                        setLogSize = 0;
                 }
 
                 if (!setLogSize) {
-                    fprintf(stderr, "ERROR: -G <num><multiplier>\n");
-                    return EXIT_FAILURE;
+                    logcat_panic(context, HELP_FALSE,
+                                 "ERROR: -G <num><multiplier>\n");
+                    goto exit;
                 }
-            }
-            break;
+            } break;
 
             case 'p':
                 if (!optarg) {
                     getPruneList = true;
                     break;
                 }
-                // FALLTHRU
+            // FALLTHRU
 
             case 'P':
                 setPruneList = optarg;
-            break;
+                break;
 
             case 'b': {
                 unsigned idMask = 0;
                 while ((optarg = strtok(optarg, ",:; \t\n\r\f")) != NULL) {
                     if (strcmp(optarg, "default") == 0) {
-                        idMask |= (1 << LOG_ID_MAIN) |
-                                  (1 << LOG_ID_SYSTEM) |
+                        idMask |= (1 << LOG_ID_MAIN) | (1 << LOG_ID_SYSTEM) |
                                   (1 << LOG_ID_CRASH);
                     } else if (strcmp(optarg, "all") == 0) {
                         allSelected = true;
                         idMask = (unsigned)-1;
                     } else {
                         log_id_t log_id = android_name_to_log_id(optarg);
-                        const char *name = android_log_id_to_name(log_id);
+                        const char* name = android_log_id_to_name(log_id);
 
                         if (strcmp(name, optarg) != 0) {
-                            logcat_panic(HELP_TRUE,
+                            logcat_panic(context, HELP_TRUE,
                                          "unknown buffer %s\n", optarg);
+                            goto exit;
                         }
                         if (log_id == LOG_ID_SECURITY) allSelected = false;
                         idMask |= (1 << log_id);
@@ -861,7 +1100,7 @@ int main(int argc, char **argv)
                 }
 
                 for (int i = LOG_ID_MIN; i < LOG_ID_MAX; ++i) {
-                    const char *name = android_log_id_to_name((log_id_t)i);
+                    const char* name = android_log_id_to_name((log_id_t)i);
                     log_id_t log_id = android_name_to_log_id(name);
 
                     if (log_id != (log_id_t)i) {
@@ -885,8 +1124,8 @@ int main(int argc, char **argv)
                         continue;
                     }
 
-                    bool binary = !strcmp(name, "events") ||
-                                  !strcmp(name, "security");
+                    bool binary =
+                        !strcmp(name, "events") || !strcmp(name, "security");
                     log_device_t* d = new log_device_t(name, binary);
 
                     if (dev) {
@@ -895,115 +1134,105 @@ int main(int argc, char **argv)
                     } else {
                         devices = dev = d;
                     }
-                    g_devCount++;
+                    context->devCount++;
                 }
-            }
-            break;
+            } break;
 
             case 'B':
-                g_printBinary = 1;
-            break;
+                context->printBinary = 1;
+                break;
 
             case 'f':
                 if ((tail_time == log_time::EPOCH) && (tail_lines == 0)) {
                     tail_time = lastLogTime(optarg);
                 }
                 // redirect output to a file
-                g_outputFileName = optarg;
-            break;
+                context->outputFileName = optarg;
+                break;
 
             case 'r':
-                if (!getSizeTArg(optarg, &g_logRotateSizeKBytes, 1)) {
-                    logcat_panic(HELP_TRUE,
+                if (!getSizeTArg(optarg, &context->logRotateSizeKBytes, 1)) {
+                    logcat_panic(context, HELP_TRUE,
                                  "Invalid parameter \"%s\" to -r\n", optarg);
+                    goto exit;
                 }
-            break;
+                break;
 
             case 'n':
-                if (!getSizeTArg(optarg, &g_maxRotatedLogs, 1)) {
-                    logcat_panic(HELP_TRUE,
+                if (!getSizeTArg(optarg, &context->maxRotatedLogs, 1)) {
+                    logcat_panic(context, HELP_TRUE,
                                  "Invalid parameter \"%s\" to -n\n", optarg);
+                    goto exit;
                 }
-            break;
+                break;
 
             case 'v':
                 if (!strcmp(optarg, "help") || !strcmp(optarg, "--help")) {
-                    show_format_help();
-                    exit(0);
+                    show_format_help(context);
+                    context->retval = EXIT_SUCCESS;
+                    goto exit;
                 }
-                err = setLogFormat(optarg);
+                err = setLogFormat(context, optarg);
                 if (err < 0) {
-                    logcat_panic(HELP_FORMAT,
+                    logcat_panic(context, HELP_FORMAT,
                                  "Invalid parameter \"%s\" to -v\n", optarg);
+                    goto exit;
                 }
                 hasSetLogFormat |= err;
-            break;
+                break;
 
             case 'Q':
-                /* this is a *hidden* option used to start a version of logcat                 */
-                /* in an emulated device only. it basically looks for androidboot.logcat=      */
-                /* on the kernel command line. If something is found, it extracts a log filter */
-                /* and uses it to run the program. If nothing is found, the program should     */
-                /* quit immediately                                                            */
-#define  KERNEL_OPTION  "androidboot.logcat="
-#define  CONSOLE_OPTION "androidboot.console="
+#define KERNEL_OPTION "androidboot.logcat="
+#define CONSOLE_OPTION "androidboot.console="
+                // This is a *hidden* option used to start a version of logcat
+                // in an emulated device only.  It basically looks for
+                // androidboot.logcat= on the kernel command line.  If
+                // something is found, it extracts a log filter and uses it to
+                // run the program.  If nothing is found, the program should
+                // quit immediately.
                 {
-                    int          fd;
-                    char*        logcat;
-                    char*        console;
-                    int          force_exit = 1;
-                    static char  cmdline[1024];
-
-                    fd = open("/proc/cmdline", O_RDONLY);
-                    if (fd >= 0) {
-                        int  n = read(fd, cmdline, sizeof(cmdline)-1 );
-                        if (n < 0) n = 0;
-                        cmdline[n] = 0;
-                        close(fd);
-                    } else {
-                        cmdline[0] = 0;
+                    std::string cmdline;
+                    android::base::ReadFileToString("/proc/cmdline", &cmdline);
+
+                    const char* logcat = strstr(cmdline.c_str(), KERNEL_OPTION);
+                    // if nothing found or invalid filters, exit quietly
+                    if (!logcat) {
+                        context->retval = EXIT_SUCCESS;
+                        goto exit;
                     }
 
-                    logcat  = strstr( cmdline, KERNEL_OPTION );
-                    console = strstr( cmdline, CONSOLE_OPTION );
-                    if (logcat != NULL) {
-                        char*  p = logcat + sizeof(KERNEL_OPTION)-1;;
-                        char*  q = strpbrk( p, " \t\n\r" );;
-
-                        if (q != NULL)
-                            *q = 0;
-
-                        forceFilters = p;
-                        force_exit   = 0;
-                    }
-                    /* if nothing found or invalid filters, exit quietly */
-                    if (force_exit) {
-                        return EXIT_SUCCESS;
+                    const char* p = logcat + strlen(KERNEL_OPTION);
+                    const char* q = strpbrk(p, " \t\n\r");
+                    if (!q) q = p + strlen(p);
+                    forceFilters = std::string(p, q);
+
+                    // redirect our output to the emulator console
+                    const char* console =
+                        strstr(cmdline.c_str(), CONSOLE_OPTION);
+                    if (!console) break;
+
+                    p = console + strlen(CONSOLE_OPTION);
+                    q = strpbrk(p, " \t\n\r");
+                    int len = q ? q - p : strlen(p);
+                    std::string devname = "/dev/" + std::string(p, len);
+                    cmdline.erase();
+
+                    if (context->error) {
+                        fprintf(context->error, "logcat using %s\n",
+                                devname.c_str());
                     }
 
-                    /* redirect our output to the emulator console */
-                    if (console) {
-                        char*  p = console + sizeof(CONSOLE_OPTION)-1;
-                        char*  q = strpbrk( p, " \t\n\r" );
-                        char   devname[64];
-                        int    len;
-
-                        if (q != NULL) {
-                            len = q - p;
-                        } else
-                            len = strlen(p);
-
-                        len = snprintf( devname, sizeof(devname), "/dev/%.*s", len, p );
-                        fprintf(stderr, "logcat using %s (%d)\n", devname, len);
-                        if (len < (int)sizeof(devname)) {
-                            fd = open( devname, O_WRONLY );
-                            if (fd >= 0) {
-                                dup2(fd, 1);
-                                dup2(fd, 2);
-                                close(fd);
-                            }
-                        }
-                    }
+                    FILE* fp = fopen(devname.c_str(), "web");
+                    devname.erase();
+                    if (!fp) break;
+
+                    // close output and error channels, replace with console
+                    android::close_output(context);
+                    android::close_error(context);
+                    context->stderr_stdout = true;
+                    context->output = fp;
+                    context->error = context->output;
+                    if (context->stderr_null) context->error = NULL;
                 }
                 break;
 
@@ -1012,103 +1241,119 @@ int main(int argc, char **argv)
                 break;
 
             case ':':
-                logcat_panic(HELP_TRUE,
+                logcat_panic(context, HELP_TRUE,
                              "Option -%c needs an argument\n", optopt);
-                break;
+                goto exit;
 
             default:
-                logcat_panic(HELP_TRUE,
-                             "Unrecognized Option %c\n", optopt);
-                break;
+                logcat_panic(context, HELP_TRUE, "Unrecognized Option %c\n",
+                             optopt);
+                goto exit;
         }
     }
 
-    if (g_maxCount && got_t) {
-        logcat_panic(HELP_TRUE,
+    if (context->maxCount && got_t) {
+        logcat_panic(context, HELP_TRUE,
                      "Cannot use -m (--max-count) and -t together\n");
+        goto exit;
     }
-    if (g_printItAnyways && (!g_regex || !g_maxCount)) {
+    if (context->printItAnyways && (!context->regex || !context->maxCount)) {
         // One day it would be nice if --print -v color and --regex <expr>
         // could play with each other and show regex highlighted content.
-        fprintf(stderr, "WARNING: "
+        // clang-format off
+        if (context->error) {
+            fprintf(context->error, "WARNING: "
                             "--print ignored, to be used in combination with\n"
-                        "         "
+                                "         "
                             "--regex <expr> and --max-count <N>\n");
-        g_printItAnyways = false;
+        }
+        context->printItAnyways = false;
     }
 
     if (!devices) {
         dev = devices = new log_device_t("main", false);
-        g_devCount = 1;
+        context->devCount = 1;
         if (android_name_to_log_id("system") == LOG_ID_SYSTEM) {
             dev = dev->next = new log_device_t("system", false);
-            g_devCount++;
+            context->devCount++;
         }
         if (android_name_to_log_id("crash") == LOG_ID_CRASH) {
             dev = dev->next = new log_device_t("crash", false);
-            g_devCount++;
+            context->devCount++;
         }
     }
 
-    if (g_logRotateSizeKBytes != 0 && g_outputFileName == NULL) {
-        logcat_panic(HELP_TRUE, "-r requires -f as well\n");
+    if (context->logRotateSizeKBytes != 0 && context->outputFileName == NULL) {
+        logcat_panic(context, HELP_TRUE, "-r requires -f as well\n");
+        goto exit;
     }
 
     if (setId != NULL) {
-        if (g_outputFileName == NULL) {
-            logcat_panic(HELP_TRUE, "--id='%s' requires -f as well\n", setId);
+        if (context->outputFileName == NULL) {
+            logcat_panic(context, HELP_TRUE,
+                         "--id='%s' requires -f as well\n", setId);
+            goto exit;
         }
 
-        std::string file_name = android::base::StringPrintf("%s.id", g_outputFileName);
+        std::string file_name = android::base::StringPrintf(
+                                        "%s.id", context->outputFileName);
         std::string file;
         bool file_ok = android::base::ReadFileToString(file_name, &file);
-        android::base::WriteStringToFile(setId, file_name,
-                                         S_IRUSR | S_IWUSR, getuid(), getgid());
+        android::base::WriteStringToFile(setId, file_name, S_IRUSR | S_IWUSR,
+                                         getuid(), getgid());
         if (!file_ok || (file.compare(setId) == 0)) {
             setId = NULL;
         }
     }
 
     if (hasSetLogFormat == 0) {
-        const char* logFormat = getenv("ANDROID_PRINTF_LOG");
+        const char* logFormat = android::getenv(context, "ANDROID_PRINTF_LOG");
 
         if (logFormat != NULL) {
-            err = setLogFormat(logFormat);
-            if (err < 0) {
-                fprintf(stderr, "invalid format in ANDROID_PRINTF_LOG '%s'\n",
-                                    logFormat);
+            err = setLogFormat(context, logFormat);
+            if ((err < 0) && context->error) {
+                fprintf(context->error,
+                        "invalid format in ANDROID_PRINTF_LOG '%s'\n",
+                        logFormat);
             }
         } else {
-            setLogFormat("threadtime");
+            setLogFormat(context, "threadtime");
         }
     }
 
-    if (forceFilters) {
-        err = android_log_addFilterString(g_logformat, forceFilters);
+    if (forceFilters.size()) {
+        err = android_log_addFilterString(context->logformat,
+                                          forceFilters.c_str());
         if (err < 0) {
-            logcat_panic(HELP_FALSE,
+            logcat_panic(context, HELP_FALSE,
                          "Invalid filter expression in logcat args\n");
+            goto exit;
         }
     } else if (argc == optind) {
         // Add from environment variable
-        char *env_tags_orig = getenv("ANDROID_LOG_TAGS");
+        const char* env_tags_orig = android::getenv(context, "ANDROID_LOG_TAGS");
 
         if (env_tags_orig != NULL) {
-            err = android_log_addFilterString(g_logformat, env_tags_orig);
+            err = android_log_addFilterString(context->logformat,
+                                              env_tags_orig);
 
             if (err < 0) {
-                logcat_panic(HELP_TRUE,
+                logcat_panic(context, HELP_TRUE,
                             "Invalid filter expression in ANDROID_LOG_TAGS\n");
+                goto exit;
             }
         }
     } else {
         // Add from commandline
         for (int i = optind ; i < argc ; i++) {
-            err = android_log_addFilterString(g_logformat, argv[i]);
+            // skip stderr redirections of _all_ kinds
+            if ((argv[i][0] == '2') && (argv[i][1] == '>')) continue;
 
+            err = android_log_addFilterString(context->logformat, argv[i]);
             if (err < 0) {
-                logcat_panic(HELP_TRUE,
+                logcat_panic(context, HELP_TRUE,
                              "Invalid filter expression '%s'\n", argv[i]);
+                goto exit;
             }
         }
     }
@@ -1119,10 +1364,6 @@ int main(int argc, char **argv)
     } else {
         logger_list = android_logger_list_alloc(mode, tail_lines, pid);
     }
-    const char *openDeviceFail = NULL;
-    const char *clearFail = NULL;
-    const char *setSizeFail = NULL;
-    const char *getSizeFail = NULL;
     // We have three orthogonal actions below to clear, set log size and
     // get log size. All sharing the same iteration loop.
     while (dev) {
@@ -1136,18 +1377,21 @@ int main(int argc, char **argv)
         }
 
         if (clearLog || setId) {
-            if (g_outputFileName) {
+            if (context->outputFileName) {
                 int maxRotationCountDigits =
-                    (g_maxRotatedLogs > 0) ? (int) (floor(log10(g_maxRotatedLogs) + 1)) : 0;
+                    (context->maxRotatedLogs > 0) ?
+                        (int)(floor(log10(context->maxRotatedLogs) + 1)) :
+                        0;
 
-                for (int i = g_maxRotatedLogs ; i >= 0 ; --i) {
+                for (int i = context->maxRotatedLogs ; i >= 0 ; --i) {
                     std::string file;
 
                     if (i == 0) {
-                        file = android::base::StringPrintf("%s", g_outputFileName);
+                        file = android::base::StringPrintf(
+                            "%s", context->outputFileName);
                     } else {
                         file = android::base::StringPrintf("%s.%.*d",
-                            g_outputFileName, maxRotationCountDigits, i);
+                            context->outputFileName, maxRotationCountDigits, i);
                     }
 
                     if (file.length() == 0) {
@@ -1181,66 +1425,79 @@ int main(int argc, char **argv)
             if ((size < 0) || (readable < 0)) {
                 reportErrorName(&getSizeFail, dev->device, allSelected);
             } else {
-                printf("%s: ring buffer is %ld%sb (%ld%sb consumed), "
-                       "max entry is %db, max payload is %db\n", dev->device,
+                std::string str = android::base::StringPrintf(
+                       "%s: ring buffer is %ld%sb (%ld%sb consumed),"
+                         " max entry is %db, max payload is %db\n",
+                       dev->device,
                        value_of_size(size), multiplier_of_size(size),
                        value_of_size(readable), multiplier_of_size(readable),
-                       (int) LOGGER_ENTRY_MAX_LEN,
-                       (int) LOGGER_ENTRY_MAX_PAYLOAD);
+                       (int)LOGGER_ENTRY_MAX_LEN,
+                       (int)LOGGER_ENTRY_MAX_PAYLOAD);
+                TEMP_FAILURE_RETRY(write(context->output_fd,
+                                         str.data(), str.length()));
             }
         }
 
         dev = dev->next;
     }
+
+    context->retval = EXIT_SUCCESS;
+
     // report any errors in the above loop and exit
     if (openDeviceFail) {
-        logcat_panic(HELP_FALSE,
+        logcat_panic(context, HELP_FALSE,
                      "Unable to open log device '%s'\n", openDeviceFail);
+        goto close;
     }
     if (clearFail) {
-        logcat_panic(HELP_FALSE,
+        logcat_panic(context, HELP_FALSE,
                      "failed to clear the '%s' log\n", clearFail);
+        goto close;
     }
     if (setSizeFail) {
-        logcat_panic(HELP_FALSE,
+        logcat_panic(context, HELP_FALSE,
                      "failed to set the '%s' log size\n", setSizeFail);
+        goto close;
     }
     if (getSizeFail) {
-        logcat_panic(HELP_FALSE,
+        logcat_panic(context, HELP_FALSE,
                      "failed to get the readable '%s' log size", getSizeFail);
+        goto close;
     }
 
     if (setPruneList) {
         size_t len = strlen(setPruneList);
-        /*extra 32 bytes are needed by  android_logger_set_prune_list */
+        // extra 32 bytes are needed by android_logger_set_prune_list
         size_t bLen = len + 32;
-        char *buf = NULL;
+        char* buf = NULL;
         if (asprintf(&buf, "%-*s", (int)(bLen - 1), setPruneList) > 0) {
             buf[len] = '\0';
             if (android_logger_set_prune_list(logger_list, buf, bLen)) {
-                logcat_panic(HELP_FALSE, "failed to set the prune list");
+                logcat_panic(context, HELP_FALSE,
+                             "failed to set the prune list");
             }
             free(buf);
         } else {
-            logcat_panic(HELP_FALSE, "failed to set the prune list (alloc)");
+            logcat_panic(context, HELP_FALSE,
+                         "failed to set the prune list (alloc)");
         }
+        goto close;
     }
 
     if (printStatistics || getPruneList) {
         size_t len = 8192;
-        char *buf;
+        char* buf;
 
-        for (int retry = 32;
-                (retry >= 0) && ((buf = new char [len]));
-                delete [] buf, buf = NULL, --retry) {
+        for (int retry = 32; (retry >= 0) && ((buf = new char[len]));
+             delete[] buf, buf = NULL, --retry) {
             if (getPruneList) {
                 android_logger_get_prune_list(logger_list, buf, len);
             } else {
                 android_logger_get_statistics(logger_list, buf, len);
             }
-            buf[len-1] = '\0';
+            buf[len - 1] = '\0';
             if (atol(buf) < 3) {
-                delete [] buf;
+                delete[] buf;
                 buf = NULL;
                 break;
             }
@@ -1253,11 +1510,12 @@ int main(int argc, char **argv)
         }
 
         if (!buf) {
-            logcat_panic(HELP_FALSE, "failed to read data");
+            logcat_panic(context, HELP_FALSE, "failed to read data");
+            goto close;
         }
 
         // remove trailing FF
-        char *cp = buf + len - 1;
+        char* cp = buf + len - 1;
         *cp = '\0';
         bool truncated = *--cp != '\f';
         if (!truncated) {
@@ -1275,37 +1533,32 @@ int main(int argc, char **argv)
             }
         }
 
-        printf("%s", cp);
-        delete [] buf;
-        return EXIT_SUCCESS;
+        len = strlen(cp);
+        TEMP_FAILURE_RETRY(write(context->output_fd, cp, len));
+        delete[] buf;
+        goto close;
     }
 
-    if (getLogSize) {
-        return EXIT_SUCCESS;
-    }
-    if (setLogSize || setPruneList) {
-        return EXIT_SUCCESS;
-    }
-    if (clearLog) {
-        return EXIT_SUCCESS;
+    if (getLogSize || setLogSize || clearLog) {
+        goto close;
     }
 
-    setupOutputAndSchedulingPolicy((mode & ANDROID_LOG_NONBLOCK) == 0);
+    setupOutputAndSchedulingPolicy(context, (mode & ANDROID_LOG_NONBLOCK) == 0);
+    if (context->stop) goto close;
 
-    //LOG_EVENT_INT(10, 12345);
-    //LOG_EVENT_LONG(11, 0x1122334455667788LL);
-    //LOG_EVENT_STRING(0, "whassup, doc?");
+    // LOG_EVENT_INT(10, 12345);
+    // LOG_EVENT_LONG(11, 0x1122334455667788LL);
+    // LOG_EVENT_STRING(0, "whassup, doc?");
 
     dev = NULL;
-    log_device_t unexpected("unexpected", false);
 
-    while (!g_maxCount || (g_printCount < g_maxCount)) {
+    while (!context->stop &&
+           (!context->maxCount || (context->printCount < context->maxCount))) {
         struct log_msg log_msg;
-        log_device_t* d;
         int ret = android_logger_list_read(logger_list, &log_msg);
-
         if (ret == 0) {
-            logcat_panic(HELP_FALSE, "read: unexpected EOF!\n");
+            logcat_panic(context, HELP_FALSE, "read: unexpected EOF!\n");
+            break;
         }
 
         if (ret < 0) {
@@ -1314,37 +1567,217 @@ int main(int argc, char **argv)
             }
 
             if (ret == -EIO) {
-                logcat_panic(HELP_FALSE, "read: unexpected EOF!\n");
+                logcat_panic(context, HELP_FALSE, "read: unexpected EOF!\n");
+                break;
             }
             if (ret == -EINVAL) {
-                logcat_panic(HELP_FALSE, "read: unexpected length.\n");
+                logcat_panic(context, HELP_FALSE, "read: unexpected length.\n");
+                break;
             }
-            logcat_panic(HELP_FALSE, "logcat read failure");
+            logcat_panic(context, HELP_FALSE, "logcat read failure");
+            break;
         }
 
+        log_device_t* d;
         for (d = devices; d; d = d->next) {
             if (android_name_to_log_id(d->device) == log_msg.id()) {
                 break;
             }
         }
         if (!d) {
-            g_devCount = 2; // set to Multiple
+            context->devCount = 2; // set to Multiple
             d = &unexpected;
             d->binary = log_msg.id() == LOG_ID_EVENTS;
         }
 
         if (dev != d) {
             dev = d;
-            maybePrintStart(dev, printDividers);
+            maybePrintStart(context, dev, printDividers);
+            if (context->stop) break;
         }
-        if (g_printBinary) {
-            printBinary(&log_msg);
+        if (context->printBinary) {
+            printBinary(context, &log_msg);
         } else {
-            processBuffer(dev, &log_msg);
+            processBuffer(context, dev, &log_msg);
         }
     }
 
+close:
     android_logger_list_free(logger_list);
 
-    return EXIT_SUCCESS;
+exit:
+    // close write end of pipe to help things along
+    if (context->output_fd == context->fds[1]) {
+        android::close_output(context);
+    }
+    if (context->error_fd == context->fds[1]) {
+        android::close_error(context);
+    }
+    if (context->fds[1] >= 0) {
+        // NB: should be closed by the above
+        int save_errno = errno;
+        close(context->fds[1]);
+        errno = save_errno;
+        context->fds[1] = -1;
+    }
+    context->thread_stopped = true;
+    return context->retval;
+}
+
+// Can block
+int android_logcat_run_command(android_logcat_context ctx,
+                               int output, int error,
+                               int argc, char* const* argv,
+                               char* const* envp) {
+    android_logcat_context_internal* context = ctx;
+
+    context->output_fd = output;
+    context->error_fd = error;
+    context->argc = argc;
+    context->argv = argv;
+    context->envp = envp;
+    context->stop = false;
+    context->thread_stopped = false;
+    return __logcat(context);
+}
+
+// starts a thread, opens a pipe, returns reading end.
+int android_logcat_run_command_thread(android_logcat_context ctx,
+                                      int argc, char* const* argv,
+                                      char* const* envp) {
+    android_logcat_context_internal* context = ctx;
+
+    int save_errno = EBUSY;
+    if ((context->fds[0] >= 0) || (context->fds[1] >= 0)) {
+        goto exit;
+    }
+
+    if (pipe(context->fds) < 0) {
+        save_errno = errno;
+        goto exit;
+    }
+
+    pthread_attr_t attr;
+    if (pthread_attr_init(&attr)) {
+        save_errno = errno;
+        goto close_exit;
+    }
+
+    struct sched_param param;
+    memset(&param, 0, sizeof(param));
+    pthread_attr_setschedparam(&attr, &param);
+    pthread_attr_setschedpolicy(&attr, SCHED_BATCH);
+    if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED)) {
+        int save_errno = errno;
+        goto pthread_attr_exit;
+    }
+
+    context->stop = false;
+    context->thread_stopped = false;
+    context->output_fd = context->fds[1];
+    // save off arguments so they remain while thread is active.
+    for (int i = 0; i < argc; ++i) {
+        context->args.push_back(std::string(argv[i]));
+    }
+    // save off environment so they remain while thread is active.
+    if (envp) for (size_t i = 0; envp[i]; ++i) {
+        context->envs.push_back(std::string(envp[i]));
+    }
+
+    for (auto& str : context->args) {
+        context->argv_hold.push_back(str.c_str());
+    }
+    context->argv_hold.push_back(NULL);
+    for (auto& str : context->envs) {
+        context->envp_hold.push_back(str.c_str());
+    }
+    context->envp_hold.push_back(NULL);
+
+    context->argc = context->argv_hold.size() - 1;
+    context->argv = (char* const*)&context->argv_hold[0];
+    context->envp = (char* const*)&context->envp_hold[0];
+
+#ifdef DEBUG
+    fprintf(stderr, "argv[%d] = {", context->argc);
+    for (auto str : context->argv_hold) {
+        fprintf(stderr, " \"%s\"", str ?: "NULL");
+    }
+    fprintf(stderr, " }\n");
+    fflush(stderr);
+#endif
+    context->retval = EXIT_SUCCESS;
+    if (pthread_create(&context->thr, &attr,
+                       (void*(*)(void*))__logcat, context)) {
+        int save_errno = errno;
+        goto argv_exit;
+    }
+    pthread_attr_destroy(&attr);
+
+    return context->fds[0];
+
+argv_exit:
+    context->argv_hold.clear();
+    context->args.clear();
+    context->envp_hold.clear();
+    context->envs.clear();
+pthread_attr_exit:
+    pthread_attr_destroy(&attr);
+close_exit:
+    close(context->fds[0]);
+    context->fds[0] = -1;
+    close(context->fds[1]);
+    context->fds[1] = -1;
+exit:
+    errno = save_errno;
+    context->stop = true;
+    context->thread_stopped = true;
+    context->retval = EXIT_FAILURE;
+    return -1;
+}
+
+// test if the thread is still doing 'stuff'
+int android_logcat_run_command_thread_running(android_logcat_context ctx) {
+    android_logcat_context_internal* context = ctx;
+
+    return context->thread_stopped == false;
+}
+
+// Finished with context
+int android_logcat_destroy(android_logcat_context* ctx) {
+    android_logcat_context_internal* context = *ctx;
+
+    *ctx = NULL;
+
+    context->stop = true;
+
+    while (context->thread_stopped == false) {
+        sched_yield();
+    }
+
+    delete context->regex;
+    context->argv_hold.clear();
+    context->args.clear();
+    context->envp_hold.clear();
+    context->envs.clear();
+    if (context->fds[0] >= 0) {
+        close(context->fds[0]);
+        context->fds[0] = -1;
+    }
+    android::close_output(context);
+    android::close_error(context);
+    if (context->fds[1] >= 0) {
+        // NB: could be closed by the above fclose(s), ignore error.
+        int save_errno = errno;
+        close(context->fds[1]);
+        errno = save_errno;
+        context->fds[1] = -1;
+    }
+
+    android_closeEventTagMap(context->eventTagMap);
+
+    int retval = context->retval;
+
+    free(context);
+
+    return retval;
 }
diff --git a/logcat/logcat_main.cpp b/logcat/logcat_main.cpp
new file mode 100644
index 000000000..9477e793e
--- /dev/null
+++ b/logcat/logcat_main.cpp
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <signal.h>
+#include <stdlib.h>
+
+#include <log/logcat.h>
+
+int main(int argc, char** argv, char** envp) {
+    android_logcat_context ctx = create_android_logcat();
+    if (!ctx) return -1;
+    signal(SIGPIPE, exit);
+    int retval = android_logcat_run_command(ctx, -1, -1, argc, argv, envp);
+    int ret = android_logcat_destroy(&ctx);
+    if (!ret) ret = retval;
+    return ret;
+}
diff --git a/logcat/logcat_system.cpp b/logcat/logcat_system.cpp
new file mode 100644
index 000000000..ea393bd67
--- /dev/null
+++ b/logcat/logcat_system.cpp
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include <log/logcat.h>
+
+static std::string unquote(const char*& cp, const char*& delim) {
+    if ((*cp == '\'') || (*cp == '"')) {
+        // KISS: Simple quotes. Do not handle the case
+        //       of concatenation like "blah"foo'bar'
+        char quote = *cp++;
+        delim = strchr(cp, quote);
+        if (!delim) delim = cp + strlen(cp);
+        std::string str(cp, delim);
+        if (*delim) ++delim;
+        return str;
+    }
+    delim = strpbrk(cp, " \t\f\r\n");
+    if (!delim) delim = cp + strlen(cp);
+    return std::string(cp, delim);
+}
+
+static bool __android_logcat_parse(const char* command,
+                                   std::vector<std::string>& args,
+                                   std::vector<std::string>& envs) {
+    for (const char *delim, *cp = command; cp && *cp; cp = delim) {
+        while (isspace(*cp)) ++cp;
+        if ((args.size() == 0) && (*cp != '=') && !isdigit(*cp)) {
+            const char* env = cp;
+            while (isalnum(*cp) || (*cp == '_')) ++cp;
+            if (cp && (*cp == '=')) {
+                std::string str(env, ++cp);
+                str += unquote(cp, delim);
+                envs.push_back(str);
+                continue;
+            }
+            cp = env;
+        }
+        args.push_back(unquote(cp, delim));
+        if ((args.size() == 1) && (args[0] != "logcat") &&
+            (args[0] != "/system/bin/logcat")) {
+            return false;
+        }
+    }
+    return args.size() != 0;
+}
+
+FILE* android_logcat_popen(android_logcat_context* ctx, const char* command) {
+    *ctx = NULL;
+
+    std::vector<std::string> args;
+    std::vector<std::string> envs;
+    if (!__android_logcat_parse(command, args, envs)) return NULL;
+
+    std::vector<const char*> argv;
+    for (auto& str : args) {
+        argv.push_back(str.c_str());
+    }
+    argv.push_back(NULL);
+
+    std::vector<const char*> envp;
+    for (auto& str : envs) {
+        envp.push_back(str.c_str());
+    }
+    envp.push_back(NULL);
+
+    *ctx = create_android_logcat();
+    if (!*ctx) return NULL;
+
+    int fd = android_logcat_run_command_thread(
+        *ctx, argv.size() - 1, (char* const*)&argv[0], (char* const*)&envp[0]);
+    argv.clear();
+    args.clear();
+    envp.clear();
+    envs.clear();
+    if (fd < 0) {
+        android_logcat_destroy(ctx);
+        return NULL;
+    }
+
+    FILE* retval = fdopen(fd, "reb");
+    if (!retval) android_logcat_destroy(ctx);
+    return retval;
+}
+
+int android_logcat_pclose(android_logcat_context* ctx, FILE* output) {
+    if (*ctx) {
+        static const useconds_t wait_sample = 20000;
+        // Wait two seconds maximum
+        for (size_t retry = ((2 * 1000000) + wait_sample - 1) / wait_sample;
+             android_logcat_run_command_thread_running(*ctx) && retry; --retry) {
+            usleep(wait_sample);
+        }
+    }
+
+    if (output) fclose(output);
+    return android_logcat_destroy(ctx);
+}
+
+int android_logcat_system(const char* command) {
+    std::vector<std::string> args;
+    std::vector<std::string> envs;
+    if (!__android_logcat_parse(command, args, envs)) return -1;
+
+    std::vector<const char*> argv;
+    for (auto& str : args) {
+        argv.push_back(str.c_str());
+    }
+    argv.push_back(NULL);
+
+    std::vector<const char*> envp;
+    for (auto& str : envs) {
+        envp.push_back(str.c_str());
+    }
+    envp.push_back(NULL);
+
+    android_logcat_context ctx = create_android_logcat();
+    if (!ctx) return -1;
+    /* Command return value */
+    int retval = android_logcat_run_command(ctx, -1, -1, argv.size() - 1,
+                                            (char* const*)&argv[0],
+                                            (char* const*)&envp[0]);
+    /* destroy return value */
+    int ret = android_logcat_destroy(&ctx);
+    /* Paranoia merging any discrepancies between the two return values */
+    if (!ret) ret = retval;
+    return ret;
+}
diff --git a/logcat/tests/Android.mk b/logcat/tests/Android.mk
index cb8b061ed..bfb20f039 100644
--- a/logcat/tests/Android.mk
+++ b/logcat/tests/Android.mk
@@ -48,6 +48,7 @@ include $(BUILD_NATIVE_TEST)
 
 test_src_files := \
     logcat_test.cpp \
+    liblogcat_test.cpp \
 
 # Build tests for the device (with .so). Run with:
 #   adb shell /data/nativetest/logcat-unit-tests/logcat-unit-tests
@@ -55,6 +56,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE := $(test_module_prefix)unit-tests
 LOCAL_MODULE_TAGS := $(test_tags)
 LOCAL_CFLAGS += $(test_c_flags)
-LOCAL_SHARED_LIBRARIES := liblog libbase
+LOCAL_SHARED_LIBRARIES := liblog libbase liblogcat
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../include
 LOCAL_SRC_FILES := $(test_src_files)
 include $(BUILD_NATIVE_TEST)
diff --git a/logcat/tests/liblogcat_test.cpp b/logcat/tests/liblogcat_test.cpp
new file mode 100644
index 000000000..9e9a2c25f
--- /dev/null
+++ b/logcat/tests/liblogcat_test.cpp
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <log/logcat.h>
+
+#define logcat_define(context) android_logcat_context context
+#define logcat_popen(context, command) android_logcat_popen(&context, command)
+#define logcat_pclose(context, fp) android_logcat_pclose(&context, fp)
+#define logcat_system(command) android_logcat_system(command)
+#define logcat liblogcat
+
+#include "logcat_test.cpp"
diff --git a/logcat/tests/logcat_test.cpp b/logcat/tests/logcat_test.cpp
index 081bf926a..9c777b3a9 100644
--- a/logcat/tests/logcat_test.cpp
+++ b/logcat/tests/logcat_test.cpp
@@ -33,36 +33,45 @@
 #include <log/log.h>
 #include <log/log_event_list.h>
 
+#ifndef logcat_popen
+#define logcat_define(context)
+#define logcat_popen(context, command) popen((command), "r")
+#define logcat_pclose(context, fp) pclose(fp)
+#define logcat_system(command) system(command)
+#endif
+
 #define BIG_BUFFER (5 * 1024)
 
 // enhanced version of LOG_FAILURE_RETRY to add support for EAGAIN and
 // non-syscall libs. Since we are only using this in the emergency of
 // a signal to stuff a terminating code into the logs, we will spin rather
 // than try a usleep.
-#define LOG_FAILURE_RETRY(exp) ({  \
-    typeof (exp) _rc;              \
-    do {                           \
-        _rc = (exp);               \
-    } while (((_rc == -1)          \
-           && ((errno == EINTR)    \
-            || (errno == EAGAIN))) \
-          || (_rc == -EINTR)       \
-          || (_rc == -EAGAIN));    \
-    _rc; })
+#define LOG_FAILURE_RETRY(exp)                                               \
+    ({                                                                       \
+        typeof(exp) _rc;                                                     \
+        do {                                                                 \
+            _rc = (exp);                                                     \
+        } while (((_rc == -1) && ((errno == EINTR) || (errno == EAGAIN))) || \
+                 (_rc == -EINTR) || (_rc == -EAGAIN));                       \
+        _rc;                                                                 \
+    })
 
 static const char begin[] = "--------- beginning of ";
 
 TEST(logcat, buckets) {
-    FILE *fp;
+    FILE* fp;
+    logcat_define(ctx);
 
 #undef LOG_TAG
 #define LOG_TAG "inject"
     RLOGE("logcat.buckets");
     sleep(1);
 
-    ASSERT_TRUE(NULL != (fp = popen(
-      "logcat -b radio -b events -b system -b main -d 2>/dev/null",
-      "r")));
+    ASSERT_TRUE(
+        NULL !=
+        (fp = logcat_popen(
+             ctx,
+             "logcat -b radio -b events -b system -b main -d 2>/dev/null")));
 
     char buffer[BIG_BUFFER];
 
@@ -71,7 +80,7 @@ TEST(logcat, buckets) {
 
     while (fgets(buffer, sizeof(buffer), fp)) {
         if (!strncmp(begin, buffer, sizeof(begin) - 1)) {
-            while (char *cp = strrchr(buffer, '\n')) {
+            while (char* cp = strrchr(buffer, '\n')) {
                 *cp = '\0';
             }
             log_id_t id = android_name_to_log_id(buffer + sizeof(begin) - 1);
@@ -80,7 +89,7 @@ TEST(logcat, buckets) {
         }
     }
 
-    pclose(fp);
+    logcat_pclose(ctx, fp);
 
     EXPECT_EQ(15, ids);
 
@@ -88,11 +97,14 @@ TEST(logcat, buckets) {
 }
 
 TEST(logcat, event_tag_filter) {
-    FILE *fp;
+    FILE* fp;
+    logcat_define(ctx);
 
-    ASSERT_TRUE(NULL != (fp = popen(
-      "logcat -b events -d -s auditd am_proc_start am_pss am_proc_bound dvm_lock_sample am_wtf 2>/dev/null",
-      "r")));
+    ASSERT_TRUE(NULL !=
+                (fp = logcat_popen(ctx,
+                                   "logcat -b events -d -s auditd "
+                                   "am_proc_start am_pss am_proc_bound "
+                                   "dvm_lock_sample am_wtf 2>/dev/null")));
 
     char buffer[BIG_BUFFER];
 
@@ -102,7 +114,7 @@ TEST(logcat, event_tag_filter) {
         ++count;
     }
 
-    pclose(fp);
+    logcat_pclose(ctx, fp);
 
     EXPECT_LT(4, count);
 }
@@ -115,7 +127,7 @@ static size_t inject(ssize_t count) {
     static const size_t retry = 4;
     size_t errors = retry;
     size_t num = 0;
-    for(;;) {
+    for (;;) {
         log_time ts(CLOCK_MONOTONIC);
         if (__android_log_btwrite(0, EVENT_TYPE_LONG, &ts, sizeof(ts)) >= 0) {
             if (++num >= (size_t)count) {
@@ -124,7 +136,7 @@ static size_t inject(ssize_t count) {
                 return num;
             }
             errors = retry;
-            usleep(100); // ~32 per timer tick, we are a spammer regardless
+            usleep(100);  // ~32 per timer tick, we are a spammer regardless
         } else if (--errors <= 0) {
             return num;
         }
@@ -134,22 +146,22 @@ static size_t inject(ssize_t count) {
 }
 
 TEST(logcat, year) {
-
     if (android_log_clockid() == CLOCK_MONOTONIC) {
         fprintf(stderr, "Skipping test, logd is monotonic time\n");
         return;
     }
 
     int count;
-    int tries = 3; // in case run too soon after system start or buffer clear
+    int tries = 3;  // in case run too soon after system start or buffer clear
 
     do {
-        FILE *fp;
+        FILE* fp;
+        logcat_define(ctx);
 
         char needle[32];
         time_t now;
         time(&now);
-        struct tm *ptm;
+        struct tm* ptm;
 #if !defined(_WIN32)
         struct tm tmBuf;
         ptm = localtime_r(&now, &tmBuf);
@@ -158,9 +170,10 @@ TEST(logcat, year) {
 #endif
         strftime(needle, sizeof(needle), "[ %Y-", ptm);
 
-        ASSERT_TRUE(NULL != (fp = popen(
-          "logcat -v long -v year -b all -t 3 2>/dev/null",
-          "r")));
+        ASSERT_TRUE(
+            NULL !=
+            (fp = logcat_popen(
+                 ctx, "logcat -v long -v year -b all -t 3 2>/dev/null")));
 
         char buffer[BIG_BUFFER];
 
@@ -171,7 +184,7 @@ TEST(logcat, year) {
                 ++count;
             }
         }
-        pclose(fp);
+        logcat_pclose(ctx, fp);
 
     } while ((count < 3) && --tries && inject(3 - count));
 
@@ -179,21 +192,21 @@ TEST(logcat, year) {
 }
 
 // Return a pointer to each null terminated -v long time field.
-char *fgetLongTime(char *buffer, size_t buflen, FILE *fp) {
+static char* fgetLongTime(char* buffer, size_t buflen, FILE* fp) {
     while (fgets(buffer, buflen, fp)) {
-        char *cp = buffer;
+        char* cp = buffer;
         if (*cp != '[') {
             continue;
         }
         while (*++cp == ' ') {
             ;
         }
-        char *ep = cp;
+        char* ep = cp;
         while (isdigit(*ep)) {
             ++ep;
         }
         if ((*ep != '-') && (*ep != '.')) {
-           continue;
+            continue;
         }
         // Find PID field
         while (((ep = strchr(ep, ':'))) && (*++ep != ' ')) {
@@ -211,21 +224,22 @@ char *fgetLongTime(char *buffer, size_t buflen, FILE *fp) {
 }
 
 TEST(logcat, tz) {
-
     if (android_log_clockid() == CLOCK_MONOTONIC) {
         fprintf(stderr, "Skipping test, logd is monotonic time\n");
         return;
     }
 
-    int tries = 4; // in case run too soon after system start or buffer clear
+    int tries = 4;  // in case run too soon after system start or buffer clear
     int count;
 
     do {
-        FILE *fp;
+        FILE* fp;
+        logcat_define(ctx);
 
-        ASSERT_TRUE(NULL != (fp = popen(
-          "logcat -v long -v America/Los_Angeles -b all -t 3 2>/dev/null",
-          "r")));
+        ASSERT_TRUE(NULL !=
+                    (fp = logcat_popen(ctx,
+                                       "logcat -v long -v America/Los_Angeles "
+                                       "-b all -t 3 2>/dev/null")));
 
         char buffer[BIG_BUFFER];
 
@@ -239,7 +253,7 @@ TEST(logcat, tz) {
             }
         }
 
-        pclose(fp);
+        logcat_pclose(ctx, fp);
 
     } while ((count < 3) && --tries && inject(3 - count));
 
@@ -247,11 +261,13 @@ TEST(logcat, tz) {
 }
 
 TEST(logcat, ntz) {
-    FILE *fp;
+    FILE* fp;
+    logcat_define(ctx);
 
-    ASSERT_TRUE(NULL != (fp = popen(
-      "logcat -v long -v America/Los_Angeles -v zone -b all -t 3 2>/dev/null",
-      "r")));
+    ASSERT_TRUE(NULL !=
+                (fp = logcat_popen(ctx,
+                                   "logcat -v long -v America/Los_Angeles -v "
+                                   "zone -b all -t 3 2>/dev/null")));
 
     char buffer[BIG_BUFFER];
 
@@ -263,13 +279,13 @@ TEST(logcat, ntz) {
         }
     }
 
-    pclose(fp);
+    logcat_pclose(ctx, fp);
 
     ASSERT_EQ(0, count);
 }
 
-void do_tail(int num) {
-    int tries = 4; // in case run too soon after system start or buffer clear
+static void do_tail(int num) {
+    int tries = 4;  // in case run too soon after system start or buffer clear
     int count;
 
     if (num > 10) ++tries;
@@ -278,10 +294,11 @@ void do_tail(int num) {
         char buffer[BIG_BUFFER];
 
         snprintf(buffer, sizeof(buffer),
-                 "logcat -v long -b all -t %d 2>/dev/null", num);
+                 "ANDROID_PRINTF_LOG=long logcat -b all -t %d 2>/dev/null", num);
 
-        FILE *fp;
-        ASSERT_TRUE(NULL != (fp = popen(buffer, "r")));
+        FILE* fp;
+        logcat_define(ctx);
+        ASSERT_TRUE(NULL != (fp = logcat_popen(ctx, buffer)));
 
         count = 0;
 
@@ -289,7 +306,7 @@ void do_tail(int num) {
             ++count;
         }
 
-        pclose(fp);
+        logcat_pclose(ctx, fp);
 
     } while ((count < num) && --tries && inject(num - count));
 
@@ -313,25 +330,27 @@ TEST(logcat, tail_1000) {
 }
 
 TEST(logcat, tail_time) {
-    FILE *fp;
+    FILE* fp;
     int count;
     char buffer[BIG_BUFFER];
-    char *last_timestamp = NULL;
+    char* last_timestamp = NULL;
     // Hard to predict 100% if first (overlap) or second line will match.
     // -v nsec will in a substantial majority be the second line.
-    char *first_timestamp = NULL;
-    char *second_timestamp = NULL;
-    char *input;
+    char* first_timestamp = NULL;
+    char* second_timestamp = NULL;
+    char* input;
 
-    int tries = 4; // in case run too soon after system start or buffer clear
+    int tries = 4;  // in case run too soon after system start or buffer clear
 
     do {
-        ASSERT_TRUE(NULL != (fp = popen("logcat"
-                                        " -v long"
-                                        " -v nsec"
-                                        " -b all"
-                                        " -t 10"
-                                        " 2>&1", "r")));
+        logcat_define(ctx);
+        ASSERT_TRUE(NULL != (fp = logcat_popen(ctx,
+                                               "logcat"
+                                               " -v long"
+                                               " -v nsec"
+                                               " -b all"
+                                               " -t 10"
+                                               " 2>&1")));
         count = 0;
 
         while ((input = fgetLongTime(buffer, sizeof(buffer), fp))) {
@@ -344,28 +363,30 @@ TEST(logcat, tail_time) {
             free(last_timestamp);
             last_timestamp = strdup(input);
         }
-        pclose(fp);
+        logcat_pclose(ctx, fp);
 
     } while ((count < 10) && --tries && inject(10 - count));
 
-    EXPECT_EQ(10, count); // We want _some_ history, too small, falses below
+    EXPECT_EQ(10, count);  // We want _some_ history, too small, falses below
     EXPECT_TRUE(last_timestamp != NULL);
     EXPECT_TRUE(first_timestamp != NULL);
     EXPECT_TRUE(second_timestamp != NULL);
 
-    snprintf(buffer, sizeof(buffer), "logcat"
-                                     " -v long"
-                                     " -v nsec"
-                                     " -b all"
-                                     " -t '%s'"
-                                     " 2>&1",
-                                     first_timestamp);
-    ASSERT_TRUE(NULL != (fp = popen(buffer, "r")));
+    snprintf(buffer, sizeof(buffer),
+             "logcat"
+             " -v long"
+             " -v nsec"
+             " -b all"
+             " -t '%s'"
+             " 2>&1",
+             first_timestamp);
+    logcat_define(ctx);
+    ASSERT_TRUE(NULL != (fp = logcat_popen(ctx, buffer)));
 
     int second_count = 0;
     int last_timestamp_count = -1;
 
-    --count; // One less unless we match the first_timestamp
+    --count;  // One less unless we match the first_timestamp
     bool found = false;
     while ((input = fgetLongTime(buffer, sizeof(buffer), fp))) {
         ++second_count;
@@ -381,9 +402,8 @@ TEST(logcat, tail_time) {
             found = !strcmp(input, first_timestamp);
             if (found) {
                 ++count;
-                GTEST_LOG_(INFO) << "input = first("
-                                 << first_timestamp
-                                 << ")\n";
+                GTEST_LOG_(INFO)
+                    << "input = first(" << first_timestamp << ")\n";
             }
             free(first_timestamp);
             first_timestamp = NULL;
@@ -391,11 +411,8 @@ TEST(logcat, tail_time) {
         if (second_timestamp) {
             found = found || !strcmp(input, second_timestamp);
             if (!found) {
-                GTEST_LOG_(INFO) << "input("
-                                 << input
-                                 << ") != second("
-                                 << second_timestamp
-                                 << ")\n";
+                GTEST_LOG_(INFO) << "input(" << input << ") != second("
+                                 << second_timestamp << ")\n";
             }
             free(second_timestamp);
             second_timestamp = NULL;
@@ -404,7 +421,7 @@ TEST(logcat, tail_time) {
             last_timestamp_count = second_count;
         }
     }
-    pclose(fp);
+    logcat_pclose(ctx, fp);
 
     EXPECT_TRUE(found);
     if (!found) {
@@ -436,10 +453,11 @@ TEST(logcat, End_to_End) {
 
     ASSERT_LT(0, __android_log_btwrite(0, EVENT_TYPE_LONG, &ts, sizeof(ts)));
 
-    FILE *fp;
-    ASSERT_TRUE(NULL != (fp = popen(
-      "logcat -v brief -b events -t 100 2>/dev/null",
-      "r")));
+    FILE* fp;
+    logcat_define(ctx);
+    ASSERT_TRUE(NULL !=
+                (fp = logcat_popen(
+                     ctx, "logcat -v brief -b events -t 100 2>/dev/null")));
 
     char buffer[BIG_BUFFER];
 
@@ -449,27 +467,28 @@ TEST(logcat, End_to_End) {
         int p;
         unsigned long long t;
 
-        if ((2 != sscanf(buffer, "I/[0]     ( %d): %llu", &p, &t))
-         || (p != pid)) {
+        if ((2 != sscanf(buffer, "I/[0]     ( %d): %llu", &p, &t)) ||
+            (p != pid)) {
             continue;
         }
 
-        log_time tx((const char *) &t);
+        log_time tx((const char*)&t);
         if (ts == tx) {
             ++count;
         }
     }
 
-    pclose(fp);
+    logcat_pclose(ctx, fp);
 
     ASSERT_EQ(1, count);
 }
 
-int get_groups(const char *cmd) {
-    FILE *fp;
+static int get_groups(const char* cmd) {
+    FILE* fp;
+    logcat_define(ctx);
 
     // NB: crash log only available in user space
-    EXPECT_TRUE(NULL != (fp = popen(cmd, "r")));
+    EXPECT_TRUE(NULL != (fp = logcat_popen(ctx, cmd)));
 
     if (fp == NULL) {
         return 0;
@@ -487,75 +506,78 @@ int get_groups(const char *cmd) {
         size = consumed = max = payload = 0;
         // NB: crash log can be very small, not hit a Kb of consumed space
         //     doubly lucky we are not including it.
-        if (6 != sscanf(buffer, "%*s ring buffer is %d%2s (%d%2s consumed),"
-                                " max entry is %db, max payload is %db",
-                                &size, size_mult, &consumed, consumed_mult,
-                                &max, &payload)) {
+        if (6 != sscanf(buffer,
+                        "%*s ring buffer is %d%2s (%d%2s consumed),"
+                        " max entry is %db, max payload is %db",
+                        &size, size_mult, &consumed, consumed_mult, &max,
+                        &payload)) {
             fprintf(stderr, "WARNING: Parse error: %s", buffer);
             continue;
         }
         full_size = size;
-        switch(size_mult[0]) {
-        case 'G':
-            full_size *= 1024;
+        switch (size_mult[0]) {
+            case 'G':
+                full_size *= 1024;
             /* FALLTHRU */
-        case 'M':
-            full_size *= 1024;
+            case 'M':
+                full_size *= 1024;
             /* FALLTHRU */
-        case 'K':
-            full_size *= 1024;
+            case 'K':
+                full_size *= 1024;
             /* FALLTHRU */
-        case 'b':
-            break;
+            case 'b':
+                break;
         }
         full_consumed = consumed;
-        switch(consumed_mult[0]) {
-        case 'G':
-            full_consumed *= 1024;
+        switch (consumed_mult[0]) {
+            case 'G':
+                full_consumed *= 1024;
             /* FALLTHRU */
-        case 'M':
-            full_consumed *= 1024;
+            case 'M':
+                full_consumed *= 1024;
             /* FALLTHRU */
-        case 'K':
-            full_consumed *= 1024;
+            case 'K':
+                full_consumed *= 1024;
             /* FALLTHRU */
-        case 'b':
-            break;
+            case 'b':
+                break;
         }
         EXPECT_GT((full_size * 9) / 4, full_consumed);
         EXPECT_GT(full_size, max);
         EXPECT_GT(max, payload);
 
-        if ((((full_size * 9) / 4) >= full_consumed)
-         && (full_size > max)
-         && (max > payload)) {
+        if ((((full_size * 9) / 4) >= full_consumed) && (full_size > max) &&
+            (max > payload)) {
             ++count;
         }
     }
 
-    pclose(fp);
+    logcat_pclose(ctx, fp);
 
     return count;
 }
 
 TEST(logcat, get_size) {
-    ASSERT_EQ(4, get_groups(
-      "logcat -v brief -b radio -b events -b system -b main -g 2>/dev/null"));
+    ASSERT_EQ(4, get_groups("logcat -v brief -b radio -b events -b system -b "
+                            "main -g 2>/dev/null"));
 }
 
 // duplicate test for get_size, but use comma-separated list of buffers
 TEST(logcat, multiple_buffer) {
-    ASSERT_EQ(4, get_groups(
-      "logcat -v brief -b radio,events,system,main -g 2>/dev/null"));
+    ASSERT_EQ(
+        4, get_groups(
+               "logcat -v brief -b radio,events,system,main -g 2>/dev/null"));
 }
 
 TEST(logcat, bad_buffer) {
-    ASSERT_EQ(0, get_groups(
-      "logcat -v brief -b radio,events,bogo,system,main -g 2>/dev/null"));
+    ASSERT_EQ(
+        0,
+        get_groups(
+            "logcat -v brief -b radio,events,bogo,system,main -g 2>/dev/null"));
 }
 
-static void caught_blocking(int signum)
-{
+#ifndef logcat
+static void caught_blocking(int signum) {
     unsigned long long v = 0xDEADBEEFA55A0000ULL;
 
     v += getpid() & 0xFFFF;
@@ -565,7 +587,7 @@ static void caught_blocking(int signum)
 }
 
 TEST(logcat, blocking) {
-    FILE *fp;
+    FILE* fp;
     unsigned long long v = 0xDEADBEEFA55F0000ULL;
 
     pid_t pid = getpid();
@@ -576,10 +598,11 @@ TEST(logcat, blocking) {
 
     v &= 0xFFFFFFFFFFFAFFFFULL;
 
-    ASSERT_TRUE(NULL != (fp = popen(
-      "( trap exit HUP QUIT INT PIPE KILL ; sleep 6; echo DONE )&"
-      " logcat -v brief -b events 2>&1",
-      "r")));
+    ASSERT_TRUE(
+        NULL !=
+        (fp = popen("( trap exit HUP QUIT INT PIPE KILL ; sleep 6; echo DONE )&"
+                    " logcat -v brief -b events 2>&1",
+                    "r")));
 
     char buffer[BIG_BUFFER];
 
@@ -590,7 +613,6 @@ TEST(logcat, blocking) {
     signal(SIGALRM, caught_blocking);
     alarm(2);
     while (fgets(buffer, sizeof(buffer), fp)) {
-
         if (!strncmp(buffer, "DONE", 4)) {
             break;
         }
@@ -600,8 +622,7 @@ TEST(logcat, blocking) {
         int p;
         unsigned long long l;
 
-        if ((2 != sscanf(buffer, "I/[0] ( %u): %lld", &p, &l))
-         || (p != pid)) {
+        if ((2 != sscanf(buffer, "I/[0] ( %u): %lld", &p, &l)) || (p != pid)) {
             continue;
         }
 
@@ -624,8 +645,7 @@ TEST(logcat, blocking) {
     EXPECT_EQ(1, signals);
 }
 
-static void caught_blocking_tail(int signum)
-{
+static void caught_blocking_tail(int signum) {
     unsigned long long v = 0xA55ADEADBEEF0000ULL;
 
     v += getpid() & 0xFFFF;
@@ -635,7 +655,7 @@ static void caught_blocking_tail(int signum)
 }
 
 TEST(logcat, blocking_tail) {
-    FILE *fp;
+    FILE* fp;
     unsigned long long v = 0xA55FDEADBEEF0000ULL;
 
     pid_t pid = getpid();
@@ -646,10 +666,11 @@ TEST(logcat, blocking_tail) {
 
     v &= 0xFFFAFFFFFFFFFFFFULL;
 
-    ASSERT_TRUE(NULL != (fp = popen(
-      "( trap exit HUP QUIT INT PIPE KILL ; sleep 6; echo DONE )&"
-      " logcat -v brief -b events -T 5 2>&1",
-      "r")));
+    ASSERT_TRUE(
+        NULL !=
+        (fp = popen("( trap exit HUP QUIT INT PIPE KILL ; sleep 6; echo DONE )&"
+                    " logcat -v brief -b events -T 5 2>&1",
+                    "r")));
 
     char buffer[BIG_BUFFER];
 
@@ -660,7 +681,6 @@ TEST(logcat, blocking_tail) {
     signal(SIGALRM, caught_blocking_tail);
     alarm(2);
     while (fgets(buffer, sizeof(buffer), fp)) {
-
         if (!strncmp(buffer, "DONE", 4)) {
             break;
         }
@@ -670,8 +690,7 @@ TEST(logcat, blocking_tail) {
         int p;
         unsigned long long l;
 
-        if ((2 != sscanf(buffer, "I/[0] ( %u): %lld", &p, &l))
-         || (p != pid)) {
+        if ((2 != sscanf(buffer, "I/[0] ( %u): %lld", &p, &l)) || (p != pid)) {
             continue;
         }
 
@@ -695,13 +714,13 @@ TEST(logcat, blocking_tail) {
 
     EXPECT_EQ(1, signals);
 }
+#endif
 
 // meant to be handed to ASSERT_FALSE / EXPECT_FALSE to expand the message
 static testing::AssertionResult IsFalse(int ret, const char* command) {
-    return ret ?
-        (testing::AssertionSuccess() <<
-            "ret=" << ret << " command=\"" << command << "\"") :
-        testing::AssertionFailure();
+    return ret ? (testing::AssertionSuccess()
+                  << "ret=" << ret << " command=\"" << command << "\"")
+               : testing::AssertionFailure();
 }
 
 TEST(logcat, logrotate) {
@@ -709,17 +728,18 @@ TEST(logcat, logrotate) {
     char buf[sizeof(form)];
     ASSERT_TRUE(NULL != mkdtemp(strcpy(buf, form)));
 
-    static const char comm[] = "logcat -b radio -b events -b system -b main"
-                                     " -d -f %s/log.txt -n 7 -r 1";
+    static const char comm[] =
+        "logcat -b radio -b events -b system -b main"
+        " -d -f %s/log.txt -n 7 -r 1";
     char command[sizeof(buf) + sizeof(comm)];
     snprintf(command, sizeof(command), comm, buf);
 
     int ret;
-    EXPECT_FALSE(IsFalse(ret = system(command), command));
+    EXPECT_FALSE(IsFalse(ret = logcat_system(command), command));
     if (!ret) {
         snprintf(command, sizeof(command), "ls -s %s 2>/dev/null", buf);
 
-        FILE *fp;
+        FILE* fp;
         EXPECT_TRUE(NULL != (fp = popen(command, "r")));
         if (fp) {
             char buffer[BIG_BUFFER];
@@ -731,7 +751,7 @@ TEST(logcat, logrotate) {
                 char c;
 
                 if ((2 == sscanf(buffer, "%d log.tx%c", &num, &c)) &&
-                        (num <= 40)) {
+                    (num <= 40)) {
                     ++count;
                 } else if (strncmp(buffer, total, sizeof(total) - 1)) {
                     fprintf(stderr, "WARNING: Parse error: %s", buffer);
@@ -749,21 +769,23 @@ TEST(logcat, logrotate) {
 }
 
 TEST(logcat, logrotate_suffix) {
-    static const char tmp_out_dir_form[] = "/data/local/tmp/logcat.logrotate.XXXXXX";
+    static const char tmp_out_dir_form[] =
+        "/data/local/tmp/logcat.logrotate.XXXXXX";
     char tmp_out_dir[sizeof(tmp_out_dir_form)];
     ASSERT_TRUE(NULL != mkdtemp(strcpy(tmp_out_dir, tmp_out_dir_form)));
 
-    static const char logcat_cmd[] = "logcat -b radio -b events -b system -b main"
-                                     " -d -f %s/log.txt -n 10 -r 1";
+    static const char logcat_cmd[] =
+        "logcat -b radio -b events -b system -b main"
+        " -d -f %s/log.txt -n 10 -r 1";
     char command[sizeof(tmp_out_dir) + sizeof(logcat_cmd)];
     snprintf(command, sizeof(command), logcat_cmd, tmp_out_dir);
 
     int ret;
-    EXPECT_FALSE(IsFalse(ret = system(command), command));
+    EXPECT_FALSE(IsFalse(ret = logcat_system(command), command));
     if (!ret) {
         snprintf(command, sizeof(command), "ls %s 2>/dev/null", tmp_out_dir);
 
-        FILE *fp;
+        FILE* fp;
         EXPECT_TRUE(NULL != (fp = popen(command, "r")));
         char buffer[BIG_BUFFER];
         int log_file_count = 0;
@@ -774,21 +796,24 @@ TEST(logcat, logrotate_suffix) {
                 strlen(rotated_log_filename_prefix);
             static const char log_filename[] = "log.txt";
 
-            if (!strncmp(buffer, rotated_log_filename_prefix, rotated_log_filename_prefix_len)) {
-              // Rotated file should have form log.txt.##
-              char* rotated_log_filename_suffix = buffer + rotated_log_filename_prefix_len;
-              char* endptr;
-              const long int suffix_value = strtol(rotated_log_filename_suffix, &endptr, 10);
-              EXPECT_EQ(rotated_log_filename_suffix + 2, endptr);
-              EXPECT_LE(suffix_value, 10);
-              EXPECT_GT(suffix_value, 0);
-              ++log_file_count;
-              continue;
+            if (!strncmp(buffer, rotated_log_filename_prefix,
+                         rotated_log_filename_prefix_len)) {
+                // Rotated file should have form log.txt.##
+                char* rotated_log_filename_suffix =
+                    buffer + rotated_log_filename_prefix_len;
+                char* endptr;
+                const long int suffix_value =
+                    strtol(rotated_log_filename_suffix, &endptr, 10);
+                EXPECT_EQ(rotated_log_filename_suffix + 2, endptr);
+                EXPECT_LE(suffix_value, 10);
+                EXPECT_GT(suffix_value, 0);
+                ++log_file_count;
+                continue;
             }
 
             if (!strncmp(buffer, log_filename, strlen(log_filename))) {
-              ++log_file_count;
-              continue;
+                ++log_file_count;
+                continue;
             }
 
             fprintf(stderr, "ERROR: Unexpected file: %s", buffer);
@@ -802,24 +827,26 @@ TEST(logcat, logrotate_suffix) {
 }
 
 TEST(logcat, logrotate_continue) {
-    static const char tmp_out_dir_form[] = "/data/local/tmp/logcat.logrotate.XXXXXX";
+    static const char tmp_out_dir_form[] =
+        "/data/local/tmp/logcat.logrotate.XXXXXX";
     char tmp_out_dir[sizeof(tmp_out_dir_form)];
     ASSERT_TRUE(NULL != mkdtemp(strcpy(tmp_out_dir, tmp_out_dir_form)));
 
     static const char log_filename[] = "log.txt";
-    static const char logcat_cmd[] = "logcat -b all -v nsec -d -f %s/%s -n 256 -r 1024";
+    static const char logcat_cmd[] =
+        "logcat -b all -v nsec -d -f %s/%s -n 256 -r 1024";
     static const char cleanup_cmd[] = "rm -rf %s";
     char command[sizeof(tmp_out_dir) + sizeof(logcat_cmd) + sizeof(log_filename)];
     snprintf(command, sizeof(command), logcat_cmd, tmp_out_dir, log_filename);
 
     int ret;
-    EXPECT_FALSE(IsFalse(ret = system(command), command));
+    EXPECT_FALSE(IsFalse(ret = logcat_system(command), command));
     if (ret) {
         snprintf(command, sizeof(command), cleanup_cmd, tmp_out_dir);
         EXPECT_FALSE(IsFalse(system(command), command));
         return;
     }
-    FILE *fp;
+    FILE* fp;
     snprintf(command, sizeof(command), "%s/%s", tmp_out_dir, log_filename);
     EXPECT_TRUE(NULL != ((fp = fopen(command, "r"))));
     if (!fp) {
@@ -827,10 +854,11 @@ TEST(logcat, logrotate_continue) {
         EXPECT_FALSE(IsFalse(system(command), command));
         return;
     }
-    char *line = NULL;
-    char *last_line = NULL; // this line is allowed to stutter, one-line overlap
-    char *second_last_line = NULL; // should never stutter
-    char *first_line = NULL; // help diagnose failure?
+    char* line = NULL;
+    char* last_line =
+        NULL;  // this line is allowed to stutter, one-line overlap
+    char* second_last_line = NULL;  // should never stutter
+    char* first_line = NULL;        // help diagnose failure?
     size_t len = 0;
     while (getline(&line, &len, fp) != -1) {
         if (!first_line) {
@@ -861,7 +889,7 @@ TEST(logcat, logrotate_continue) {
     // re-run the command, it should only add a few lines more content if it
     // continues where it left off.
     snprintf(command, sizeof(command), logcat_cmd, tmp_out_dir, log_filename);
-    EXPECT_FALSE(IsFalse(ret = system(command), command));
+    EXPECT_FALSE(IsFalse(ret = logcat_system(command), command));
     if (ret) {
         snprintf(command, sizeof(command), cleanup_cmd, tmp_out_dir);
         EXPECT_FALSE(IsFalse(system(command), command));
@@ -869,7 +897,8 @@ TEST(logcat, logrotate_continue) {
         free(first_line);
         return;
     }
-    std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(tmp_out_dir), closedir);
+    std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(tmp_out_dir),
+                                                  closedir);
     EXPECT_NE(nullptr, dir);
     if (!dir) {
         snprintf(command, sizeof(command), cleanup_cmd, tmp_out_dir);
@@ -878,7 +907,7 @@ TEST(logcat, logrotate_continue) {
         free(first_line);
         return;
     }
-    struct dirent *entry;
+    struct dirent* entry;
     unsigned count = 0;
     while ((entry = readdir(dir.get()))) {
         if (strncmp(entry->d_name, log_filename, sizeof(log_filename) - 1)) {
@@ -904,15 +933,15 @@ TEST(logcat, logrotate_continue) {
         unlink(command);
     }
     if (count > 1) {
-        char *brk = strpbrk(second_last_line, "\r\n");
+        char* brk = strpbrk(second_last_line, "\r\n");
         if (!brk) brk = second_last_line + strlen(second_last_line);
         fprintf(stderr, "\"%.*s\" occurred %u times\n",
-            (int)(brk - second_last_line), second_last_line, count);
+                (int)(brk - second_last_line), second_last_line, count);
         if (first_line) {
             brk = strpbrk(first_line, "\r\n");
             if (!brk) brk = first_line + strlen(first_line);
             fprintf(stderr, "\"%.*s\" was first line, fault?\n",
-                (int)(brk - first_line), first_line);
+                    (int)(brk - first_line), first_line);
         }
     }
     free(second_last_line);
@@ -923,7 +952,8 @@ TEST(logcat, logrotate_continue) {
 }
 
 TEST(logcat, logrotate_clear) {
-    static const char tmp_out_dir_form[] = "/data/local/tmp/logcat.logrotate.XXXXXX";
+    static const char tmp_out_dir_form[] =
+        "/data/local/tmp/logcat.logrotate.XXXXXX";
     char tmp_out_dir[sizeof(tmp_out_dir_form)];
     ASSERT_TRUE(NULL != mkdtemp(strcpy(tmp_out_dir, tmp_out_dir_form)));
 
@@ -932,28 +962,30 @@ TEST(logcat, logrotate_clear) {
     static const char logcat_cmd[] = "logcat -b all -d -f %s/%s -n %d -r 1";
     static const char clear_cmd[] = " -c";
     static const char cleanup_cmd[] = "rm -rf %s";
-    char command[sizeof(tmp_out_dir) + sizeof(logcat_cmd) + sizeof(log_filename) + sizeof(clear_cmd) + 32];
+    char command[sizeof(tmp_out_dir) + sizeof(logcat_cmd) +
+                 sizeof(log_filename) + sizeof(clear_cmd) + 32];
 
     // Run command with all data
     {
-        snprintf(command, sizeof(command) - sizeof(clear_cmd),
-                 logcat_cmd, tmp_out_dir, log_filename, num_val);
+        snprintf(command, sizeof(command) - sizeof(clear_cmd), logcat_cmd,
+                 tmp_out_dir, log_filename, num_val);
 
         int ret;
-        EXPECT_FALSE(IsFalse(ret = system(command), command));
+        EXPECT_FALSE(IsFalse(ret = logcat_system(command), command));
         if (ret) {
             snprintf(command, sizeof(command), cleanup_cmd, tmp_out_dir);
             EXPECT_FALSE(IsFalse(system(command), command));
             return;
         }
-        std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(tmp_out_dir), closedir);
+        std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(tmp_out_dir),
+                                                      closedir);
         EXPECT_NE(nullptr, dir);
         if (!dir) {
             snprintf(command, sizeof(command), cleanup_cmd, tmp_out_dir);
             EXPECT_FALSE(IsFalse(system(command), command));
             return;
         }
-        struct dirent *entry;
+        struct dirent* entry;
         unsigned count = 0;
         while ((entry = readdir(dir.get()))) {
             if (strncmp(entry->d_name, log_filename, sizeof(log_filename) - 1)) {
@@ -969,21 +1001,22 @@ TEST(logcat, logrotate_clear) {
         strcat(command, clear_cmd);
 
         int ret;
-        EXPECT_FALSE(IsFalse(ret = system(command), command));
+        EXPECT_FALSE(IsFalse(ret = logcat_system(command), command));
         if (ret) {
             snprintf(command, sizeof(command), cleanup_cmd, tmp_out_dir);
             EXPECT_FALSE(system(command));
             EXPECT_FALSE(IsFalse(system(command), command));
             return;
         }
-        std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(tmp_out_dir), closedir);
+        std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(tmp_out_dir),
+                                                      closedir);
         EXPECT_NE(nullptr, dir);
         if (!dir) {
             snprintf(command, sizeof(command), cleanup_cmd, tmp_out_dir);
             EXPECT_FALSE(IsFalse(system(command), command));
             return;
         }
-        struct dirent *entry;
+        struct dirent* entry;
         unsigned count = 0;
         while ((entry = readdir(dir.get()))) {
             if (strncmp(entry->d_name, log_filename, sizeof(log_filename) - 1)) {
@@ -999,24 +1032,25 @@ TEST(logcat, logrotate_clear) {
     EXPECT_FALSE(IsFalse(system(command), command));
 }
 
-static int logrotate_count_id(const char *logcat_cmd, const char *tmp_out_dir) {
-
+static int logrotate_count_id(const char* logcat_cmd, const char* tmp_out_dir) {
     static const char log_filename[] = "log.txt";
-    char command[strlen(tmp_out_dir) + strlen(logcat_cmd) + strlen(log_filename) + 32];
+    char command[strlen(tmp_out_dir) + strlen(logcat_cmd) +
+                 strlen(log_filename) + 32];
 
     snprintf(command, sizeof(command), logcat_cmd, tmp_out_dir, log_filename);
 
-    int ret;
-    EXPECT_FALSE(IsFalse(ret = system(command), command));
+    int ret = logcat_system(command);
     if (ret) {
+        fprintf(stderr, "system(\"%s\")=%d", command, ret);
         return -1;
     }
-    std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(tmp_out_dir), closedir);
-    EXPECT_NE(nullptr, dir);
+    std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(tmp_out_dir),
+                                                  closedir);
     if (!dir) {
+        fprintf(stderr, "opendir(\"%s\") failed", tmp_out_dir);
         return -1;
     }
-    struct dirent *entry;
+    struct dirent* entry;
     int count = 0;
     while ((entry = readdir(dir.get()))) {
         if (strncmp(entry->d_name, log_filename, sizeof(log_filename) - 1)) {
@@ -1028,9 +1062,12 @@ static int logrotate_count_id(const char *logcat_cmd, const char *tmp_out_dir) {
 }
 
 TEST(logcat, logrotate_id) {
-    static const char logcat_cmd[] = "logcat -b all -d -f %s/%s -n 32 -r 1 --id=test";
-    static const char logcat_short_cmd[] = "logcat -b all -t 10 -f %s/%s -n 32 -r 1 --id=test";
-    static const char tmp_out_dir_form[] = "/data/local/tmp/logcat.logrotate.XXXXXX";
+    static const char logcat_cmd[] =
+        "logcat -b all -d -f %s/%s -n 32 -r 1 --id=test";
+    static const char logcat_short_cmd[] =
+        "logcat -b all -t 10 -f %s/%s -n 32 -r 1 --id=test";
+    static const char tmp_out_dir_form[] =
+        "/data/local/tmp/logcat.logrotate.XXXXXX";
     static const char log_filename[] = "log.txt";
     char tmp_out_dir[strlen(tmp_out_dir_form) + 1];
     ASSERT_TRUE(NULL != mkdtemp(strcpy(tmp_out_dir, tmp_out_dir_form)));
@@ -1047,19 +1084,21 @@ TEST(logcat, logrotate_id) {
     unlink(id_file);
     EXPECT_EQ(34, logrotate_count_id(logcat_short_cmd, tmp_out_dir));
 
-    FILE *fp = fopen(id_file, "w");
+    FILE* fp = fopen(id_file, "w");
     if (fp) {
         fprintf(fp, "not_a_test");
         fclose(fp);
     }
     if (getuid() != 0) {
-        chmod(id_file, 0); // API to preserve content even with signature change
+        chmod(id_file,
+              0);  // API to preserve content even with signature change
         ASSERT_EQ(34, logrotate_count_id(logcat_short_cmd, tmp_out_dir));
         chmod(id_file, 0600);
     }
 
     int new_signature;
-    EXPECT_LE(2, (new_signature = logrotate_count_id(logcat_short_cmd, tmp_out_dir)));
+    EXPECT_LE(
+        2, (new_signature = logrotate_count_id(logcat_short_cmd, tmp_out_dir)));
     EXPECT_GT(34, new_signature);
 
     static const char cleanup_cmd[] = "rm -rf %s";
@@ -1069,13 +1108,15 @@ TEST(logcat, logrotate_id) {
 }
 
 TEST(logcat, logrotate_nodir) {
-    // expect logcat to error out on writing content and exit(1) for nodir
-    EXPECT_EQ(W_EXITCODE(1, 0),
-              system("logcat -b all -d"
-                     " -f /das/nein/gerfingerpoken/logcat/log.txt"
-                     " -n 256 -r 1024"));
+    // expect logcat to error out on writing content and not exit(0) for nodir
+    static const char command[] =
+        "logcat -b all -d"
+        " -f /das/nein/gerfingerpoken/logcat/log.txt"
+        " -n 256 -r 1024";
+    EXPECT_FALSE(IsFalse(0 == logcat_system(command), command));
 }
 
+#ifndef logcat
 static void caught_blocking_clear(int signum) {
     unsigned long long v = 0xDEADBEEFA55C0000ULL;
 
@@ -1086,7 +1127,7 @@ static void caught_blocking_clear(int signum) {
 }
 
 TEST(logcat, blocking_clear) {
-    FILE *fp;
+    FILE* fp;
     unsigned long long v = 0xDEADBEEFA55C0000ULL;
 
     pid_t pid = getpid();
@@ -1095,12 +1136,13 @@ TEST(logcat, blocking_clear) {
 
     // This test is racey; an event occurs between clear and dump.
     // We accept that we will get a false positive, but never a false negative.
-    ASSERT_TRUE(NULL != (fp = popen(
-      "( trap exit HUP QUIT INT PIPE KILL ; sleep 6; echo DONE )&"
-      " logcat -b events -c 2>&1 ;"
-      " logcat -b events -g 2>&1 ;"
-      " logcat -v brief -b events 2>&1",
-      "r")));
+    ASSERT_TRUE(
+        NULL !=
+        (fp = popen("( trap exit HUP QUIT INT PIPE KILL ; sleep 6; echo DONE )&"
+                    " logcat -b events -c 2>&1 ;"
+                    " logcat -b events -g 2>&1 ;"
+                    " logcat -v brief -b events 2>&1",
+                    "r")));
 
     char buffer[BIG_BUFFER];
 
@@ -1112,7 +1154,6 @@ TEST(logcat, blocking_clear) {
     signal(SIGALRM, caught_blocking_clear);
     alarm(2);
     while (fgets(buffer, sizeof(buffer), fp)) {
-
         if (!strncmp(buffer, "clearLog: ", 10)) {
             fprintf(stderr, "WARNING: Test lacks permission to run :-(\n");
             count = signals = 1;
@@ -1126,37 +1167,38 @@ TEST(logcat, blocking_clear) {
         int size, consumed, max, payload;
         char size_mult[3], consumed_mult[3];
         size = consumed = max = payload = 0;
-        if (6 == sscanf(buffer, "events: ring buffer is %d%2s (%d%2s consumed),"
-                                " max entry is %db, max payload is %db",
-                                &size, size_mult, &consumed, consumed_mult,
-                                &max, &payload)) {
+        if (6 == sscanf(buffer,
+                        "events: ring buffer is %d%2s (%d%2s consumed),"
+                        " max entry is %db, max payload is %db",
+                        &size, size_mult, &consumed, consumed_mult, &max,
+                        &payload)) {
             long full_size = size, full_consumed = consumed;
 
-            switch(size_mult[0]) {
-            case 'G':
-                full_size *= 1024;
+            switch (size_mult[0]) {
+                case 'G':
+                    full_size *= 1024;
                 /* FALLTHRU */
-            case 'M':
-                full_size *= 1024;
+                case 'M':
+                    full_size *= 1024;
                 /* FALLTHRU */
-            case 'K':
-                full_size *= 1024;
+                case 'K':
+                    full_size *= 1024;
                 /* FALLTHRU */
-            case 'b':
-                break;
+                case 'b':
+                    break;
             }
-            switch(consumed_mult[0]) {
-            case 'G':
-                full_consumed *= 1024;
+            switch (consumed_mult[0]) {
+                case 'G':
+                    full_consumed *= 1024;
                 /* FALLTHRU */
-            case 'M':
-                full_consumed *= 1024;
+                case 'M':
+                    full_consumed *= 1024;
                 /* FALLTHRU */
-            case 'K':
-                full_consumed *= 1024;
+                case 'K':
+                    full_consumed *= 1024;
                 /* FALLTHRU */
-            case 'b':
-                break;
+                case 'b':
+                    break;
             }
             EXPECT_GT(full_size, full_consumed);
             EXPECT_GT(full_size, max);
@@ -1172,8 +1214,7 @@ TEST(logcat, blocking_clear) {
         int p;
         unsigned long long l;
 
-        if ((2 != sscanf(buffer, "I/[0] ( %u): %lld", &p, &l))
-         || (p != pid)) {
+        if ((2 != sscanf(buffer, "I/[0] ( %u): %lld", &p, &l)) || (p != pid)) {
             continue;
         }
 
@@ -1199,11 +1240,13 @@ TEST(logcat, blocking_clear) {
 
     EXPECT_EQ(1, signals);
 }
+#endif
 
-static bool get_white_black(char **list) {
-    FILE *fp;
+static bool get_white_black(char** list) {
+    FILE* fp;
+    logcat_define(ctx);
 
-    fp = popen("logcat -p 2>/dev/null", "r");
+    fp = logcat_popen(ctx, "logcat -p 2>/dev/null");
     if (fp == NULL) {
         fprintf(stderr, "ERROR: logcat -p 2>/dev/null\n");
         return false;
@@ -1212,12 +1255,12 @@ static bool get_white_black(char **list) {
     char buffer[BIG_BUFFER];
 
     while (fgets(buffer, sizeof(buffer), fp)) {
-        char *hold = *list;
-        char *buf = buffer;
+        char* hold = *list;
+        char* buf = buffer;
         while (isspace(*buf)) {
             ++buf;
         }
-        char *end = buf + strlen(buf);
+        char* end = buf + strlen(buf);
         while (isspace(*--end) && (end >= buf)) {
             *end = '\0';
         }
@@ -1231,28 +1274,29 @@ static bool get_white_black(char **list) {
             asprintf(list, "%s", buf);
         }
     }
-    pclose(fp);
+    logcat_pclose(ctx, fp);
     return *list != NULL;
 }
 
-static bool set_white_black(const char *list) {
-    FILE *fp;
+static bool set_white_black(const char* list) {
+    FILE* fp;
+    logcat_define(ctx);
 
     char buffer[BIG_BUFFER];
 
     snprintf(buffer, sizeof(buffer), "logcat -P '%s' 2>&1", list ? list : "");
-    fp = popen(buffer, "r");
+    fp = logcat_popen(ctx, buffer);
     if (fp == NULL) {
         fprintf(stderr, "ERROR: %s\n", buffer);
         return false;
     }
 
     while (fgets(buffer, sizeof(buffer), fp)) {
-        char *buf = buffer;
+        char* buf = buffer;
         while (isspace(*buf)) {
             ++buf;
         }
-        char *end = buf + strlen(buf);
+        char* end = buf + strlen(buf);
         while ((end > buf) && isspace(*--end)) {
             *end = '\0';
         }
@@ -1260,15 +1304,15 @@ static bool set_white_black(const char *list) {
             continue;
         }
         fprintf(stderr, "%s\n", buf);
-        pclose(fp);
+        logcat_pclose(ctx, fp);
         return false;
     }
-    return pclose(fp) == 0;
+    return logcat_pclose(ctx, fp) == 0;
 }
 
 TEST(logcat, white_black_adjust) {
-    char *list = NULL;
-    char *adjust = NULL;
+    char* list = NULL;
+    char* adjust = NULL;
 
     get_white_black(&list);
 
@@ -1297,55 +1341,72 @@ TEST(logcat, white_black_adjust) {
 }
 
 TEST(logcat, regex) {
-    FILE *fp;
+    FILE* fp;
+    logcat_define(ctx);
     int count = 0;
 
     char buffer[BIG_BUFFER];
+// Have to make liblogcat data unique from logcat data injection
+#ifdef logcat
+#define logcat_regex_prefix "lolcat_test"
+#else
+#define logcat_regex_prefix "logcat_test"
+#endif
 
-    snprintf(buffer, sizeof(buffer), "logcat --pid %d -d -e logcat_test_a+b", getpid());
-
-    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test_ab"));
-    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test_b"));
-    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test_aaaab"));
-    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test_aaaa"));
-
+    snprintf(buffer, sizeof(buffer),
+             "logcat --pid %d -d -e " logcat_regex_prefix "_a+b", getpid());
+
+    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, logcat_regex_prefix,
+                                          logcat_regex_prefix "_ab"));
+    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, logcat_regex_prefix,
+                                          logcat_regex_prefix "_b"));
+    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, logcat_regex_prefix,
+                                          logcat_regex_prefix "_aaaab"));
+    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, logcat_regex_prefix,
+                                          logcat_regex_prefix "_aaaa"));
     // Let the logs settle
     sleep(1);
 
-    ASSERT_TRUE(NULL != (fp = popen(buffer, "r")));
+    ASSERT_TRUE(NULL != (fp = logcat_popen(ctx, buffer)));
 
     while (fgets(buffer, sizeof(buffer), fp)) {
         if (!strncmp(begin, buffer, sizeof(begin) - 1)) {
             continue;
         }
 
-        EXPECT_TRUE(strstr(buffer, "logcat_test_") != NULL);
+        EXPECT_TRUE(strstr(buffer, logcat_regex_prefix "_") != NULL);
 
         count++;
     }
 
-    pclose(fp);
+    logcat_pclose(ctx, fp);
 
     ASSERT_EQ(2, count);
 }
 
 TEST(logcat, maxcount) {
-    FILE *fp;
+    FILE* fp;
+    logcat_define(ctx);
     int count = 0;
 
     char buffer[BIG_BUFFER];
 
-    snprintf(buffer, sizeof(buffer), "logcat --pid %d -d --max-count 3", getpid());
+    snprintf(buffer, sizeof(buffer), "logcat --pid %d -d --max-count 3",
+             getpid());
 
-    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test"));
-    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test"));
-    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test"));
-    LOG_FAILURE_RETRY(__android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test"));
+    LOG_FAILURE_RETRY(
+        __android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test"));
+    LOG_FAILURE_RETRY(
+        __android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test"));
+    LOG_FAILURE_RETRY(
+        __android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test"));
+    LOG_FAILURE_RETRY(
+        __android_log_print(ANDROID_LOG_WARN, "logcat_test", "logcat_test"));
 
     // Let the logs settle
     sleep(1);
 
-    ASSERT_TRUE(NULL != (fp = popen(buffer, "r")));
+    ASSERT_TRUE(NULL != (fp = logcat_popen(ctx, buffer)));
 
     while (fgets(buffer, sizeof(buffer), fp)) {
         if (!strncmp(begin, buffer, sizeof(begin) - 1)) {
@@ -1355,7 +1416,7 @@ TEST(logcat, maxcount) {
         count++;
     }
 
-    pclose(fp);
+    logcat_pclose(ctx, fp);
 
     ASSERT_EQ(3, count);
 }
@@ -1367,8 +1428,18 @@ static bool End_to_End(const char* tag, const char* fmt, ...)
     ;
 
 static bool End_to_End(const char* tag, const char* fmt, ...) {
-    FILE *fp = popen("logcat -v brief -b events -v descriptive -t 100 2>/dev/null", "r");
-    if (!fp) return false;
+    logcat_define(ctx);
+    FILE* fp = logcat_popen(ctx,
+                            "logcat"
+                            " -v brief"
+                            " -b events"
+                            " -v descriptive"
+                            " -t 100"
+                            " 2>/dev/null");
+    if (!fp) {
+        fprintf(stderr, "End_to_End: popen failed");
+        return false;
+    }
 
     char buffer[BIG_BUFFER];
     va_list ap;
@@ -1377,7 +1448,7 @@ static bool End_to_End(const char* tag, const char* fmt, ...) {
     vsnprintf(buffer, sizeof(buffer), fmt, ap);
     va_end(ap);
 
-    char *str = NULL;
+    char* str = NULL;
     asprintf(&str, "I/%s ( %%d):%%c%s%%c", tag, buffer);
     std::string expect(str);
     free(str);
@@ -1399,15 +1470,19 @@ static bool End_to_End(const char* tag, const char* fmt, ...) {
         }
     }
 
-    pclose(fp);
+    logcat_pclose(ctx, fp);
 
     if ((count == 0) && (lastMatch.length() > 0)) {
         // Help us pinpoint where things went wrong ...
         fprintf(stderr, "Closest match for\n    %s\n  is\n    %s",
                 expect.c_str(), lastMatch.c_str());
+    } else if (count > 2) {
+        fprintf(stderr, "Too many matches (%d) for %s\n", count, expect.c_str());
     }
 
-    return count == 1;
+    // Expect one the first time around as either liblogcat.descriptive or
+    // logcat.descriptive.  Expect two the second time as the other.
+    return count == 1 || count == 2;
 }
 
 TEST(logcat, descriptive) {
@@ -1422,8 +1497,8 @@ TEST(logcat, descriptive) {
         static const char theAnswer[] = "what is five by seven";
         ctx << theAnswer;
         ctx.write();
-        EXPECT_TRUE(End_to_End(hhgtg.tagStr,
-                               "to life the universe etc=%s", theAnswer));
+        EXPECT_TRUE(
+            End_to_End(hhgtg.tagStr, "to life the universe etc=%s", theAnswer));
     }
 
     {
@@ -1434,8 +1509,7 @@ TEST(logcat, descriptive) {
             ctx << id << (int32_t)42 << (int32_t)-1 << (int32_t)0;
             ctx.write();
             EXPECT_TRUE(End_to_End(sync.tagStr,
-                                   "[id=%s,event=42,source=-1,account=0]",
-                                   id));
+                                   "[id=%s,event=42,source=-1,account=0]", id));
         }
 
         // Partial match to description
@@ -1443,9 +1517,7 @@ TEST(logcat, descriptive) {
             android_log_event_list ctx(sync.tagNo);
             ctx << id << (int32_t)43 << (int64_t)-1 << (int32_t)0;
             ctx.write();
-            EXPECT_TRUE(End_to_End(sync.tagStr,
-                                   "[id=%s,event=43,-1,0]",
-                                   id));
+            EXPECT_TRUE(End_to_End(sync.tagStr, "[id=%s,event=43,-1,0]", id));
         }
 
         // Negative Test of End_to_End, ensure it is working
@@ -1454,9 +1526,8 @@ TEST(logcat, descriptive) {
             ctx << id << (int32_t)44 << (int32_t)-1 << (int64_t)0;
             ctx.write();
             fprintf(stderr, "Expect a \"Closest match\" message\n");
-            EXPECT_FALSE(End_to_End(sync.tagStr,
-                                    "[id=%s,event=44,source=-1,account=0]",
-                                    id));
+            EXPECT_FALSE(End_to_End(
+                sync.tagStr, "[id=%s,event=44,source=-1,account=0]", id));
         }
     }
 
@@ -1466,16 +1537,16 @@ TEST(logcat, descriptive) {
             android_log_event_list ctx(sync.tagNo);
             ctx << (uint64_t)30 << (int32_t)2;
             ctx.write();
-            EXPECT_TRUE(End_to_End(sync.tagStr,
-                                   "[aggregation time=30ms,count=2]"));
+            EXPECT_TRUE(
+                End_to_End(sync.tagStr, "[aggregation time=30ms,count=2]"));
         }
 
         {
             android_log_event_list ctx(sync.tagNo);
             ctx << (uint64_t)31570 << (int32_t)911;
             ctx.write();
-            EXPECT_TRUE(End_to_End(sync.tagStr,
-                                   "[aggregation time=31.57s,count=911]"));
+            EXPECT_TRUE(
+                End_to_End(sync.tagStr, "[aggregation time=31.57s,count=911]"));
         }
     }
 
@@ -1518,7 +1589,7 @@ TEST(logcat, descriptive) {
 
         {
             android_log_event_list ctx(sync.tagNo);
-            ctx << (uint32_t)3221225472; // 3MB, but on purpose overflowed
+            ctx << (uint32_t)3221225472;  // 3MB, but on purpose overflowed
             ctx.write();
             EXPECT_TRUE(End_to_End(sync.tagStr, "current=-1GB"));
         }
@@ -1533,12 +1604,13 @@ TEST(logcat, descriptive) {
 }
 
 static bool reportedSecurity(const char* command) {
-    FILE* fp = popen(command, "r");
+    logcat_define(ctx);
+    FILE* fp = logcat_popen(ctx, command);
     if (!fp) return true;
 
     std::string ret;
     bool val = android::base::ReadFdToString(fileno(fp), &ret);
-    pclose(fp);
+    logcat_pclose(ctx, fp);
 
     if (!val) return true;
     return std::string::npos != ret.find("'security'");