int builtins_fg(int ac, char **av, t_config *conf, int *ret)
{
change_signal(0);
*ret = 0;
if (ac == 1 && put_in_foreground(conf->head_job, conf) == -1)
{
*ret = -1;
my_puterr("fg: No current job.\n");
}
else if (ac == 2)
{
if (check_job_and_put_in_foreground(conf->head_job, av[1], conf) == -1)
{
*ret = -1;
my_puterr("fg: No such job.\n");
}
}
else if (ac != 1)
{
*ret = -1;
my_puterr("fg: No such job.\n");
}
change_signal(1);
return (MYSH_SIGNAL_NOPE);
}
// move a job into the foreground
int cmd_fg(tok_t arg[]){
process* p;
if( arg[0] != NULL )
p = get_process( atoi( arg[0] ) );
else if( first_process != NULL )
p = first_process->prev;
if( p != NULL ){
put_in_foreground( p, true );
}
return 1;
}
void sh_continue(job_t *job, int foreground)
{
/* Mark suspended job as running again */
process_t *p = job->first_process;
for (; p != NULL; p = p->next)
p->suspended = 0;
job->notified = 0;
/* Put in fg or bg, sending non-zero cont */
if (foreground)
put_in_foreground(job, 1);
else
put_in_background(job, 1);
}
int
shell( int argc, char *argv[] ) {
init_shell(); // initialize the shell
pid_t pid = getpid(); // get current processe's PID
pid_t ppid = getppid(); // get parent's PID
pid_t cpid, tcpid, cpgid;
print_welcome( argv[0], pid, ppid );
print_prompt();
char *s = malloc(INPUT_STRING_SIZE + 1); // user input string
while( (s = freadln(stdin)) ){ // read in the input string
process *p = create_process( s );
if( p != NULL ){ // do we need to run a newly created process?
cpid = fork(); // fork off a child
if( cpid == 0 ) { // child
p->pid = getpid();
launch_process( p );
} // if( cpid == 0 )
else if( cpid > 0 ){ // parent
p->pid = cpid;
if( shell_is_interactive ){ // are we running shell from a terminal?
// put 'p' into its own process group
// since our shell is not supporting pipes, we treat
// each process by itself as a 'job' to be done
if( setpgid( cpid, cpid ) < 0 )
printf( "Failed to put the child into its own process group.\n" );
if( p->background )
put_in_background( p, false );
else
put_in_foreground( p, false );
} // if( shell_is_interactive )
else
wait_for_process( p );
} // else if( cpid > 0 )
else // fork() failed
printf( "fork() failed\n" );
} // if( p != NULL )
print_prompt();
} // while
return EXIT_SUCCESS;
} // shell
void sh_launch_job(job_t *job, int foreground)
{
process_t *p; /* Process iteration */
pid_t pid; /* PID for the newly spawned process */
int output; /* Output file descriptor */
int input = job->stdin; /* Input file descriptor */
int iopipe[2] = {STDIN_FILENO, STDOUT_FILENO}; /* Inter-process comms pipe */
for (p = job->first_process; p != NULL; p = p->next) {
/* Set up pipes if applicable, set output */
if (p->next != NULL) {
check(pipe(iopipe) >= 0);
output = iopipe[1];
} else {
output = job->stdout;
}
/* Fork child process and launch */
check((pid = fork()) >= 0);
if (pid == 0) {
/* I am the fork */
sh_launch_process(p, job->pgid, input, output,
job->stderr, foreground);
} else {
/* I am parent */
p->pid = pid;
if (shell_interactive) {
/*
* if (job->pgid == 0)
* job->pgid = pid;
*
* MAN specifies that if pgid is 0, pid of
* indicated process (pid) shall be used.
*/
setpgid(pid, job->pgid);
}
}
/* Clean up the pipes, set input */
if (input != job->stdin)
close(input);
if (output != job->stdout)
close(output);
input = iopipe[0];
}
format_job_info(job, "launched");
/* Either wait until job is finished, or engage new */
if (!shell_interactive)
job_wait_blocked(job);
else if (foreground)
put_in_foreground(job, 0);
else
put_in_background(job, 0);
}
