/**

 * @file

 * Execute external programs

 *

 * @authors

 * Copyright (C) 1996-2000,2013 Michael R. Elkins <me@mutt.org>

 * Copyright (C) 2017-2023 Richard Russon <rich@flatcap.org>

 *

 * @copyright

 * This program is free software: you can redistribute it and/or modify it under

 * the terms of the GNU General Public License as published by the Free Software

 * Foundation, either version 2 of the License, or (at your option) any later

 * version.

 *

 * This program is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more

 * details.

 *

 * You should have received a copy of the GNU General Public License along with

 * this program.  If not, see <http://www.gnu.org/licenses/>.

 */

/**

 * @page neo_system Execute external programs

 *

 * Execute external programs

 */

#include "config.h"

#include <signal.h>

#include <stdbool.h>

#include <stdlib.h>

#include <sys/types.h>

#include <sys/wait.h> // IWYU pragma: keep

#include <unistd.h>

#include "mutt/lib.h"

#include "core/lib.h"

#include "imap/lib.h"

#include "protos.h"

/**

 * mutt_system - Run an external command

 * @param cmd Command and arguments

 * @retval -1  Error

 * @retval >=0 Success (command's return code)

 *

 * Fork and run an external command with arguments.

 *

 * @note This function won't return until the command finishes.

 */

int mutt_system(const char *cmd)

{

  int rc = -1;

  struct sigaction act = { 0 };

  struct sigaction oldtstp = { 0 };

  struct sigaction oldcont = { 0 };

  pid_t pid;

  if (!cmd || (*cmd == '\0'))

    return 0;

  /* must ignore SIGINT and SIGQUIT */

  mutt_sig_block_system();

  act.sa_handler = SIG_DFL;

/* we want to restart the waitpid() below */

#ifdef SA_RESTART

  act.sa_flags = SA_RESTART;

#endif

  sigemptyset(&act.sa_mask);

  sigaction(SIGTSTP, &act, &oldtstp);

  sigaction(SIGCONT, &act, &oldcont);

  pid = fork();

  if (pid == 0)

  {

    act.sa_flags = 0;

    mutt_sig_unblock_system(false);

    mutt_sig_reset_child_signals();

    execle(EXEC_SHELL, "sh", "-c", cmd, NULL, NeoMutt->env);

    _exit(127); /* execl error */

  }

  else if (pid != -1)

  {

    rc = imap_wait_keep_alive(pid);

  }

  sigaction(SIGCONT, &oldcont, NULL);

  sigaction(SIGTSTP, &oldtstp, NULL);

  /* reset SIGINT, SIGQUIT and SIGCHLD */

  mutt_sig_unblock_system(true);

  rc = (pid != -1) ? (WIFEXITED(rc) ? WEXITSTATUS(rc) : -1) : -1;

  return rc;

}