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/*
* Copyright (C) 2013 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.
*/
#define LOG_TAG "forkpty"
#include <utils/Log.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <termios.h>
#include <unistd.h>
#include "forkpty.h"
pid_t forkpty(int *master, int *slave, const struct termios *termp,
const struct winsize *winp) {
int ptm = open("/dev/ptmx", O_RDWR);
if (ptm < 0) {
ALOGE("cannot open /dev/ptmx - %s", strerror(errno));
return -1;
}
fcntl(ptm, F_SETFD, FD_CLOEXEC);
char *devname;
if (grantpt(ptm) || unlockpt(ptm) || ((devname = (char *) ptsname(ptm)) == 0)) {
ALOGE("error opening pty - %s", strerror(errno));
return -1;
}
int pts = open(devname, O_RDWR);
if (pts < 0) {
ALOGE("unable to open slave pty - %s", strerror(errno));
return -1;
}
if (termp) {
tcsetattr(pts, TCSAFLUSH, termp);
}
if (winp) {
ioctl(pts, TIOCSWINSZ, winp);
}
pid_t pid = fork();
if (pid < 0) {
ALOGE("fork failed - %s", strerror(errno));
return -1;
}
if (pid == 0) {
setsid();
if (ioctl(pts, TIOCSCTTY, (char *)NULL) == -1) exit(-1);
dup2(pts, STDIN_FILENO);
dup2(pts, STDOUT_FILENO);
dup2(pts, STDERR_FILENO);
if (pts > 2) {
close(pts);
}
} else {
*master = ptm;
if (slave) {
*slave = pts;
}
}
return pid;
}
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