return 0;
}
-int execute_command(const char *command, const char *subsystem)
+int execute_program(const char *command, const char *subsystem,
+ char *result, size_t ressize, size_t *reslen)
{
- int retval;
+ int retval = 0;
+ int count;
+ int status;
+ int pipefds[2];
pid_t pid;
- char arg[PATH_SIZE];
- char *argv[(PATH_SIZE / 2) + 1];
char *pos;
+ char arg[PATH_SIZE];
+ char *argv[(sizeof(arg) / 2) + 1];
int devnull;
int i;
+ size_t len;
strlcpy(arg, command, sizeof(arg));
i = 0;
dbg("execute '%s' with subsystem '%s' argument", arg, argv[1]);
}
+ if (result) {
+ if (pipe(pipefds) != 0) {
+ err("pipe failed");
+ return -1;
+ }
+ }
+
pid = fork();
- switch (pid) {
+ switch(pid) {
case 0:
- /* child */
+ /* child dup2 write side of pipe to STDOUT */
devnull = open("/dev/null", O_RDWR);
if (devnull >= 0) {
dup2(devnull, STDIN_FILENO);
- dup2(devnull, STDOUT_FILENO);
+ if (!result)
+ dup2(devnull, STDOUT_FILENO);
dup2(devnull, STDERR_FILENO);
close(devnull);
}
- retval = execv(arg, argv);
- err("exec of child '%s' failed", command);
+ if (result)
+ dup2(pipefds[1], STDOUT_FILENO);
+ execv(arg, argv);
+ err("exec of program failed");
_exit(1);
case -1:
- dbg("fork of child '%s' failed", command);
- break;
+ err("fork of '%s' failed", arg);
return -1;
default:
- waitpid(pid, NULL, 0);
+ /* parent reads from pipefds[0] */
+ if (result) {
+ close(pipefds[1]);
+ len = 0;
+ while (1) {
+ count = read(pipefds[0], result + len, ressize - len-1);
+ if (count < 0) {
+ err("read failed with '%s'", strerror(errno));
+ retval = -1;
+ break;
+ }
+
+ if (count == 0)
+ break;
+
+ len += count;
+ if (len >= ressize-1) {
+ err("ressize %d too short", ressize);
+ retval = -1;
+ break;
+ }
+ }
+ result[len] = '\0';
+ close(pipefds[0]);
+ if (reslen)
+ *reslen = len;
+ }
+ waitpid(pid, &status, 0);
+
+ if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
+ dbg("exec program status 0x%x", status);
+ retval = -1;
+ }
}
- return 0;
+ return retval;
}