/* do_fg - Execute the builtin fg command */
void
do_fg(char **argv)
{
struct job_t * job;
pid_t pid;
if (verbose)
printf("do_fg: entering\n");
job = treat_argv(argv);
job->jb_state = FG;
pid = jobs_fgpid();
assert(kill(-pid, SIGCONT) != -1);
if (verbose)
printf("do_fg: sigcont %d \n", pid);
waitfg(pid);
if (verbose)
printf("do_fg: exiting\n");
return;
}
/* waitfg - Block until process pid is no longer the foreground process */
void
waitfg(pid_t pid)
{
sigset_t vide;
sigset_t masque;
if (verbose)
printf("waitfg: entering\n");
sigemptyset(&masque);
sigemptyset(&vide);
sigaddset(&masque, SIGCHLD);
assert(sigprocmask(SIG_SETMASK, &masque, NULL) != -1);
while(pid==jobs_fgpid()) {
sigsuspend(&vide);
}
sigprocmask(SIG_SETMASK, &vide, NULL);
if (verbose)
printf("waitfg: exiting\n");
return;
}
/*
* sigint_handler - The kernel sends a SIGINT to the shell whenver the
* user types ctrl-c at the keyboard. Catch it and send it along
* to the foreground job.
*/
void sigint_handler(int sig)
{
int pid;
if (verbose) printf("sigint_handler: entering\n");
if ((pid = jobs_fgpid()))
kill(pid,sig); /* sig or SIGINT */
if (verbose) printf("sigint_handler: exiting\n");
return;
}
/*
* sigtstp_handler - The kernel sends a SIGTSTP to the shell whenever
* the user types ctrl-z at the keyboard. Catch it and supid : 6031, getpid 6030
spend the
* foreground job by sending it a SIGTSTP.
*/
void sigtstp_handler(int sig)
{
int pid;
if (verbose) printf("sigtstp_handler: entering\n");
;
if ((pid = jobs_fgpid()))
kill(pid,SIGSTOP); /* sig or SIGTSTP */
if (verbose) printf("sigtstp_handler: exiting\n");
return;
}
/*
* sigint_handler - The kernel sends a SIGINT to the shell whenver the
* user types ctrl-c at the keyboard. Catch it and send it along
* to the foreground job.
*/
void
sigint_handler(int sig)
{
pid_t pid;
if (verbose)
printf("sigint_handler: entering\n");
if ((pid = jobs_fgpid()) > 0){
/* send SIGINT signal to the job of PID=pid*/
kill(pid,SIGINT);
}
if (verbose)
printf("sigint_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;
}
