/* treat_argv - Determine pid or jobid and return the associated job structure */
struct job_t *
treat_argv(char **argv) {
struct job_t *jobp = NULL;
/* Ignore command if no argument */
if (argv[1] == NULL) {
printf("%s command requires PID or %%jobid argument\n", argv[0]);
return NULL;
}
/* Parse the required PID or %JID arg */
if (isdigit((int) argv[1][0])) {
pid_t pid = atoi(argv[1]);
if (!(jobp = jobs_getjobpid(pid))) {
printf("(%d): No such process\n", (int) pid);
return NULL;
}
}
else if (argv[1][0] == '%') {
int jid = atoi(&argv[1][1]);
if (!(jobp = jobs_getjobjid(jid))) {
printf("%s: No such job\n", argv[1]);
return NULL;
}
}
else {
printf("%s: argument must be a PID or %%jobid\n", argv[0]);
return NULL;
}
return jobp;
}
/* waitfg - Block until process pid is no longer the foreground process */
void waitfg(pid_t pid) {
struct job_t *job;
if (verbose) {
printf("Entering wait FG\n");
}
job=jobs_getjobpid(pid);
if (job == NULL) {
if (verbose) {
printf("Non existing job : exiting wait FG\n");
}
return;
}
while (job->jb_pid == pid && job->jb_state == FG) {
sleep(1);
if (verbose) {
fprintf(stderr, "Waiting\n");
}
}
if (verbose) {
printf("Exiting wait FG\n");
}
return;
}
/* waitfg - Block until process pid is no longer the foreground process */
void
waitfg(pid_t pid)
{
struct job_t *j;
sigset_t maskchld;
sigset_t masknormal;
j = jobs_getjobpid(pid);
if (!j)
return;
/* maskchld initialization (no signal) */
sigemptyset(&maskchld);
/* Adding SIGCHLD signal to maskchld */
sigaddset(&maskchld, SIGCHLD);
/* Initialize masknormal with previous blocked signals, then block */
/* all previous blocked signals and all signals in maskchld signals. */
/* This call ensures that a SIGCHLD isn't caught by a sighandler */
sigprocmask(SIG_BLOCK, &maskchld, &masknormal);
while (j->jb_pid == pid && j->jb_state == FG) {
/* Wait for a signal which isn't blocked in masknormal set, */
/* ignoring mask previously sets by sigprocmask calls, */
/* potentially catching some previous blocked signals */
/* (i.e. blocked SIGCHLD) */
sigsuspend(&masknormal);
}
/* Back to previous blocked signals only */
sigprocmask(SIG_SETMASK, &masknormal, NULL);
return;
}
/*
* sigchld_handler - The kernel sends a SIGCHLD to the shell whenever
* a child job terminates (becomes a zombie), or stops because it
* received a SIGSTOP or SIGTSTP signal. The handler reaps all
* available zombie children
*/
void
sigchld_handler(int sig)
{
pid_t pid;
int status;
struct job_t *job;
if (verbose)
printf("sigchld_handler: entering\n");
while ((pid = waitpid(-1,&status,WUNTRACED)) > 0){
job = jobs_getjobpid(pid);
if (WIFEXITED(status)){ /*if job exited normally*/
printf("[%d] (%d) Terminated \t\t %s\n",job->jb_jid,pid,job->jb_cmdline);
if(!jobs_deletejob(pid)) /* delete the job */
unix_error("error while deleting job");
} else if (WIFSTOPPED(status)){/*if job received a stop signal*/
job->jb_state = ST; /* change the job state */
printf("[%d] (%d) Suspended \t\t %s\n",job->jb_jid,pid,job->jb_cmdline);
} else if (WIFSIGNALED(status)){/*if job was killed*/
printf("[%d] (%d) Killed \t\t %s\n",job->jb_jid,pid,job->jb_cmdline);
if(!jobs_deletejob(pid)) /* delete the job */
unix_error("error while deleting job");
}
if (verbose)
printf("sigchld_handler: exiting\n");
return;
}
}
/*
* sigchld_handler - The kernel sends a SIGCHLD to the shell whenever
* a child job terminates (becomes a zombie), or stops because it
* received a SIGSTOP or SIGTSTP signal. The handler reaps all
* available zombie children
*/
void sigchld_handler(int sig)
{
struct job_t* job;
int status, pid;
if (verbose) printf("sigchld_handler: entering\n");
if ((pid = waitpid(-1,&status,WNOHANG | WUNTRACED)) == -1)
pid = jobs_fgpid();
if (pid > 0)
{
job = jobs_getjobpid(pid);
if (WIFSTOPPED(status))
{
job->jb_state = ST;
printf("[%d] (%d) : Stopped\n",job->jb_jid,job->jb_pid);
}
else if (WIFEXITED(status))
{
printf("[%d] (%d) : Exited\n",job->jb_jid,job->jb_pid);
jobs_deletejob(pid);
}
else if (WIFSIGNALED(status))
{
printf("[%d] (%d) : Exited by User\n",job->jb_jid,job->jb_pid);
jobs_deletejob(pid);
}
else
{
printf("Error on : [%d] (%d) - %s \n",job->jb_jid,job->jb_pid,job->jb_cmdline);
}
}
if (verbose) printf("sigchld_handler: exiting\n");
return;
}
