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#include "ground.h"
using namespace std;
namespace ov4
{
pid_t shell_pgid;
int tty_fd;
/*
* waitfg - Block until process pid is no longer the foreground process
*/
void waitfg(pid_t pid)
{
sigset_t prev_with_sigchld_unblocked;
// get current blocked signals
sigprocmask(0, nullptr, &prev_with_sigchld_unblocked);
sigdelset(&prev_with_sigchld_unblocked, SIGCHLD);
LOG << "waiting for pid "<< fgpid(jobs) << endl;
while (fgpid(jobs) != 0)
sigsuspend(&prev_with_sigchld_unblocked);
// set shell to foreground again
tcsetpgrp(tty_fd, shell_pgid);
sigprocmask(SIG_BLOCK, &block_io, nullptr);
LOG << "finished fg " << endl;
return;
}
/*
* do_bgfg - Execute the builtin bg and fg commands
*/
void do_bgfg(char **argv)
{
if ((strcmp(argv[0], "fg") == 0) || (strcmp(argv[0], "bg") == 0))
{
int x;
job_t *j = nullptr;
sigset_t prev;
if (argv[1] == nullptr)
{
cerr << ((strcmp(argv[0], "fg") == 0) ? "fg" : "bg") << " command requires PID or %jobid argument" << endl;
return;
}
if (argv[1][0] == '%') // jid provided
{
if (!isnum(&argv[1][1]))
{
cerr << ((strcmp(argv[0], "fg") == 0) ? "fg" : "bg") << ": argument must be a PID or %jobid" << endl;
return;
}
x = atoi(&argv[1][1]); // eat %
j = getjobjid(jobs, x);
if (j == nullptr)
{
cerr << argv[1] << ": No such job" << endl;
return;
}
} else { // pid
if (!isnum(&argv[1][0]))
{
cerr << ((strcmp(argv[0], "fg") == 0) ? "fg" : "bg") << ": argument must be a PID or %jobid" << endl;
return;
}
x = atoi(&argv[1][0]);
j = getjobpid(jobs, x);
if (j == nullptr)
{
cerr << "(" << argv[1] << "): No such process" << endl;
return;
}
}
block_all(&prev);
if (strcmp(argv[0], "fg") == 0) // fg
{
LOG << "fg" << endl;
j->state = FG;
sigset_t prev_with_sigchld_blocked = prev;
sigaddset(&prev_with_sigchld_blocked, SIGCHLD);
sigprocmask(SIG_SETMASK, &prev_with_sigchld_blocked, NULL);
if (kill(-(j->pid), SIGCONT) < 0)
{
cerr << "Cannot continue process " << j->pid;
sigprocmask(SIG_SETMASK, &prev, NULL);
return;
}
waitfg(j->pid);
sigprocmask(SIG_SETMASK, &prev, NULL);
} else // bg
{
LOG << "bg" << endl;
j->state = BG;
kill(-(j->pid), SIGCONT);
sigprocmask(SIG_SETMASK, &prev, NULL);
// cmdline has nerd '\n' at the end
// so just flush
cout << "[" << j->jid << "] (" << j->pid << ") " << j->cmdline << flush;
}
}
else
cerr << "not fg/bg" << endl;
}
}
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