libfsobasics: add own implementation of pidof method

2 files changed, 59 insertions, 0 deletions

diff --git a/libfsobasics/fsobasics/process.vala b/libfsobasics/fsobasics/process.vala
index 83205554..28244a69 100644
--- a/libfsobasics/fsobasics/process.vala
+++ b/libfsobasics/fsobasics/process.vala
@@ -17,6 +17,8 @@
  *
  */
 
+using FsoFramework.FileHandling;
+
 /**
  * @interface FsoFramework.IProcessGuard
  **/
@@ -34,6 +36,55 @@ public interface FsoFramework.IProcessGuard : GLib.Object
 }
 
 /**
+ * Some process relevant utility functions
+ **/
+namespace FsoFramework.Process
+{
+    private static const string PROC_PATH = "/proc";
+
+    public Posix.pid_t pidof( string name )
+    {
+        int result = 0;
+        int pid = 0;
+        string statfile, pstat, comm, pname;
+        string[] stat_info;
+        string[] subdirs = listDirectory( PROC_PATH );
+
+        foreach ( var dirname in subdirs )
+        {
+            pid = dirname.to_int();
+
+            // check for invalid pid and ignore them
+            if ( pid <= 0 )
+                continue;
+
+            // Now we have a valid pid, find out more about the process! (see man 5 proc
+            // for more details)
+            statfile = @"$(PROC_PATH)/$(pid)/stat";
+            if ( !isPresent(statfile) )
+                continue;
+
+            pstat = read( statfile );
+            stat_info = pstat.split( " " );
+
+            // validate process command name for correct length
+            if ( !( stat_info.length >= 2 ) && stat_info[0].length > 2 )
+                continue;
+
+            // extract and check process name for the correct one
+            pname = (stat_info[1])[1:stat_info[1].length-2];
+            if ( name.has_prefix( pname ) )
+            {
+                result = pid;
+                break;
+            }
+        }
+
+        return (Posix.pid_t) result;
+    }
+}
+
+/**
  * @class FsoFramework.GProcessGuard
  **/
 public class FsoFramework.GProcessGuard : FsoFramework.IProcessGuard, GLib.Object
diff --git a/libfsobasics/tests/testprocess.vala b/libfsobasics/tests/testprocess.vala
index 257e107f..30286230 100644
--- a/libfsobasics/tests/testprocess.vala
+++ b/libfsobasics/tests/testprocess.vala
@@ -81,6 +81,13 @@ void test_process_kill_implicit()
 }
 
 //===========================================================================
+void test_pidof()
+//===========================================================================
+{
+    assert( FsoFramework.Process.pidof( "init" ) == 1 );
+}
+
+//===========================================================================
 void main (string[] args)
 //===========================================================================
 {
@@ -90,6 +97,7 @@ void main (string[] args)
     Test.add_func( "/Process/signals", test_process_signals );
     Test.add_func( "/Process/kill/explicit", test_process_kill_explicit );
     Test.add_func( "/Process/kill/implicit", test_process_kill_implicit );
+    Test.add_func( "/Process/pidof", test_pidof );
 
     Test.run ();
 }