int
main(int argc, char *argv[])
{
- int master, slave, cc, sendeof = 0, status;
- time_t starttime;
+ int master_in, master_out, slave, cc, status;
+ time_t starttime, now;
const char *slavename;
pid_t child;
unsigned char readbuf[1024];
exit(1);
}
- if ((master = posix_openpt(O_RDWR | O_NOCTTY)) < 0) {
+ if ((master_in = posix_openpt(O_RDWR | O_NOCTTY)) < 0) {
fprintf(stderr, "Unable to open master pseudo-tty: %s\n",
strerror(errno));
exit(1);
}
- if (grantpt(master) < 0) {
- fprintf(stderr, "Unable to grant permissions to master pty: %s\n",
+ if ((master_out = posix_openpt(O_RDWR | O_NOCTTY)) < 0) {
+ fprintf(stderr, "Unable to open master pseudo-tty: %s\n",
strerror(errno));
exit(1);
}
- if (unlockpt(master) < 0) {
- fprintf(stderr, "Unable to unlock master pty: %s\n", strerror(errno));
+ if (grantpt(master_in) < 0) {
+ fprintf(stderr, "Unable to grant permissions to master pty: %s\n",
+ strerror(errno));
exit(1);
}
- if (!(slavename = ptsname(master))) {
- fprintf(stderr, "Unable to determine name of slave pty: %s\n",
+ if (grantpt(master_out) < 0) {
+ fprintf(stderr, "Unable to grant permissions to master pty: %s\n",
strerror(errno));
exit(1);
}
- if ((slave = open(slavename, O_RDWR | O_NOCTTY)) < 0) {
- fprintf(stderr, "Unable to open slave pty \"%s\": %s\n", slavename,
- strerror(errno));
+ if (unlockpt(master_in) < 0) {
+ fprintf(stderr, "Unable to unlock master pty: %s\n", strerror(errno));
+ exit(1);
+ }
+
+ if (unlockpt(master_out) < 0) {
+ fprintf(stderr, "Unable to unlock master pty: %s\n", strerror(errno));
exit(1);
}
child = fork();
/*
- * Start the child process if we are in the child; close the master
- * as we are supposed to only use the slave ptys here.
+ * Start the child process if we are in the child; open the two
+ * slave pseudo-ttys and close the masters after we are done with them.
*/
if (child == 0) {
- close(master);
+ if (!(slavename = ptsname(master_in))) {
+ fprintf(stderr, "Unable to determine name of slave pty: %s\n",
+ strerror(errno));
+ exit(1);
+ }
+
+ if ((slave = open(slavename, O_RDWR)) < 0) {
+ fprintf(stderr, "Unable to open slave pty \"%s\": %s\n", slavename,
+ strerror(errno));
+ exit(1);
+ }
+
dup2(slave, STDIN_FILENO);
+ close(slave);
+ close(master_in);
+
+ if (!(slavename = ptsname(master_out))) {
+ fprintf(stderr, "Unable to determine name of slave pty: %s\n",
+ strerror(errno));
+ exit(1);
+ }
+
+ if ((slave = open(slavename, O_RDWR | O_NOCTTY)) < 0) {
+ fprintf(stderr, "Unable to open slave pty \"%s\": %s\n", slavename,
+ strerror(errno));
+ exit(1);
+ }
+
dup2(slave, STDOUT_FILENO);
dup2(slave, STDERR_FILENO);
close(slave);
+ close(master_out);
execvp(argv[2], argv + 2);
fprintf(stderr, "execvp(%s) failed: %s\n", argv[2], strerror(errno));
+ exit(1);
+
} else if (child < 0) {
fprintf(stderr, "fork() failed: %s\n", strerror(errno));
exit(1);
}
- close(slave);
-
if (!(output = fopen(argv[1], "w"))) {
fprintf(stderr, "Unable to open \"%s\" for output: %s\n", argv[1],
strerror(errno));
FD_ZERO(&readfds);
- FD_SET(master, &readfds);
+ FD_SET(master_out, &readfds);
/*
- * Okay, what's going on here?
- *
- * We want to send the EOF character (to simulate a "end of file",
- * as if we redirected stdin to /dev/null). We can't just close
- * master, because we won't be able to get any data back. So,
- * after we get SOME data, set sendeof, and that will cause us to
- * send the EOF character after the first select call. If we are
- * doing sendeof, set the timeout to 1 second; otherwise, set the
- * timeout to COMMAND_TIMEOUT seconds remaining.
+ * After we get our first bit of data, close the master pty
+ * connected to standard input on our slave; that will generate
+ * an EOF.
*/
- if (sendeof) {
- tv.tv_sec = 1;
- } else {
- tv.tv_sec = starttime + COMMAND_TIMEOUT - time(NULL);
- if (tv.tv_sec < 0)
- tv.tv_sec = 0;
- }
+ tv.tv_sec = starttime + COMMAND_TIMEOUT - time(NULL);
+ if (tv.tv_sec < 0)
+ tv.tv_sec = 0;
tv.tv_usec = 0;
- cc = select(master + 1, &readfds, NULL, NULL, &tv);
+ cc = select(master_out + 1, &readfds, NULL, NULL, &tv);
if (cc < 0) {
fprintf(stderr, "select() failed: %s\n", strerror(errno));
exit(1);
}
- if (cc > 0 && FD_ISSET(master, &readfds)) {
- cc = read(master, readbuf, sizeof(readbuf));
+ if (cc > 0 && FD_ISSET(master_out, &readfds)) {
+ cc = read(master_out, readbuf, sizeof(readbuf));
if (cc <= 0)
break;
fwrite(readbuf, 1, cc, output);
- }
-
- if (cc == 0 && sendeof) {
- struct termios rtty;
- if (tcgetattr(master, &rtty) < 0) {
- fprintf(stderr, "tcgetattr() failed: %s\n", strerror(errno));
- exit(1);
+ if (master_in != -1) {
+ close(master_in);
+ master_in = -1;
}
+ }
- if (rtty.c_lflag & ICANON)
- write(master, &rtty.c_cc[VEOF], 1);
- } else if (!sendeof)
- sendeof = 1;
-
- if (time(NULL) > starttime + COMMAND_TIMEOUT) {
- fprintf(stderr, "Command execution timed out\n");
+ now = time(NULL);
+ if (now >= starttime + COMMAND_TIMEOUT) {
+ fprintf(stderr, "Command execution timed out: %ld to %ld: %d\n",
+ starttime, now, cc);
break;
}
}
- close(master);
+ if (master_in != -1)
+ close(master_in);
+ close(master_out);
fclose(output);
waitpid(child, &status, 0);
projects / nmh / blobdiff