gboolean
ck_job_cancel (CkJob *job)
{
if (job->priv->child_pid > 0) {
kill (job->priv->child_pid, SIGTERM);
wait_on_job (job);
return TRUE;
}
return FALSE;
}
static void
maybe_complete_job (CkJob *job)
{
if (job->priv->out_watch_id == 0
&& job->priv->err_watch_id == 0) {
int status;
status = wait_on_job (job);
g_debug ("Emitting completed");
g_signal_emit (job, signals [COMPLETED], 0, status);
}
}
/* Continue job with specifed pgid in the foreground */
void resume_foreground_job(pid_t pgid) {
job_t* j = find_job(pgid); //obtain job with specified processs group ID
j->bg = false; //if was in background before, it is no longer
process_t* p;
for (p = j->first_process; p; p = p->next) {
if (p->stopped) { //ID stopped processes in specified job and resume them
p->stopped = false;
p->status = -1;
}
}
tcsetpgrp(shell_terminal, j->pgid); //move the job to the terminal foreground
continue_job(j); //send SIGCONT signal
wait_on_job(j); //suspend dsh until job exits or stops
tcsetpgrp(shell_terminal, shell_pgid); //when foregroung job exits or stops, return control to dsh
}
void spawn_job(job_t *j, bool fg) {
pid_t pid;
process_t *p;
int read_fd = -1;
/* Check for input/output redirection; If present, set the IO descriptors
* to the appropriate files given by the user
*/
/* A job can contain a pipeline; Loop through process and set up pipes accordingly */
/* For each command (process), fork to create a new process context,
* set the process group, and execute the command
*/
/* The code below provides an example on how to set the process context for each command */
for(p = j->first_process; p; p = p->next) { //if job has multiple processes it means they are linked by pipes, so assign accordingly
int fd[2] = {-1,-1};
if(p->next != NULL){
pipe(fd);
}
switch (pid = fork()) {
case -1: /* fork failure */
perror("fork");
exit(EXIT_FAILURE);
case 0: /* child */
/* establish a new process group, and put the child in
* foreground if requested
*/
if (j->pgid < 0) {/* init sets -ve to a new process */
j->pgid = getpid();
fprintf(stdout, "%d(Launched): %s\n", j->pgid, j->commandinfo);
}
p->pid = 0;
if (!setpgid(0,j->pgid))
if(fg) // If success and fg is set
tcsetpgrp(shell_terminal, j->pgid); // assign the terminal
/* Set the handling for job control signals back to the default. */
signal(SIGTTOU, SIG_DFL);
if (read_fd > 0) {
dup2(read_fd, STDIN_FILENO);
}
else if (j->mystdin == INPUT_FD) {
dup2(open(j->ifile, O_RDONLY), STDIN_FILENO);
}
if (fd[1] > 0) {
dup2(fd[1], STDOUT_FILENO);
}
else if (j->mystdout == OUTPUT_FD) {
dup2(open(j->ofile, O_WRONLY|O_CREAT|O_TRUNC, 0664),
STDOUT_FILENO);
}
dup2(log_fd, STDERR_FILENO);
execvp(p->argv[0], p->argv);
perror("now you done f****d up"); //exec only returns on failure, so exit
exit(1);
default: /* parent */
/* establish child process group here to avoid race
* conditions. */
p->pid = pid;
if (j->pgid <= 0)
j->pgid = pid;
setpgid(pid, j->pgid);
if (read_fd > 0)
close(read_fd);
if (fd[1] > 0)
close(fd[1]);
read_fd = fd[0];
}
}
if (fg) {
wait_on_job(j);
}
tcsetpgrp(shell_terminal, shell_pgid);
}
