builtins/suspend.def

   1 This file is suspend.def, from which is created suspend.c.
   2 It implements the builtin "suspend" in Bash.
   3
   4 Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.
   5
   6 This file is part of GNU Bash, the Bourne Again SHell.
   7
   8 Bash is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 2, or (at your option) any later
  11 version.
  12
  13 Bash is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License along
  19 with Bash; see the file COPYING.  If not, write to the Free Software
  20 Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
  21
  22 $PRODUCES suspend.c
  23
  24 $BUILTIN suspend
  25 $DEPENDS_ON JOB_CONTROL
  26 $FUNCTION suspend_builtin
  27 $SHORT_DOC suspend [-f]
  28 Suspend the execution of this shell until it receives a SIGCONT
  29 signal.  The `-f' if specified says not to complain about this
  30 being a login shell if it is; just suspend anyway.
  31 $END
  32
  33 #include <config.h>
  34
  35 #if defined (JOB_CONTROL)
  36 #if defined (HAVE_UNISTD_H)
  37 #  ifdef _MINIX
  38 #    include <sys/types.h>
  39 #  endif
  40 #  include <unistd.h>
  41 #endif
  42
  43 #include "../bashtypes.h"
  44 #include <signal.h>
  45 #include "../shell.h"
  46 #include "../jobs.h"
  47 #include "common.h"
  48 #include "bashgetopt.h"
  49
  50 extern int job_control;
  51
  52 static SigHandler *old_cont;
  53 #if 0
  54 static SigHandler *old_stop;
  55 #endif
  56
  57 /* Continue handler. */
  58 sighandler
  59 suspend_continue (sig)
  60      int sig;
  61 {
  62   set_signal_handler (SIGCONT, old_cont);
  63 #if 0
  64   set_signal_handler (SIGSTOP, old_stop);
  65 #endif
  66   SIGRETURN (0);
  67 }
  68
  69 /* Suspending the shell.  If -f is the arg, then do the suspend
  70    no matter what.  Otherwise, complain if a login shell. */
  71 int
  72 suspend_builtin (list)
  73      WORD_LIST *list;
  74 {
  75   int opt, force;
  76
  77   reset_internal_getopt ();
  78   force = 0;
  79   while ((opt = internal_getopt (list, "f")) != -1)
  80     switch (opt)
  81       {
  82       case 'f':
  83         force++;
  84         break;
  85       default:
  86         builtin_usage ();
  87         return (EX_USAGE);
  88       }
  89
  90   list = loptend;
  91
  92   if (job_control == 0)
  93     {
  94       builtin_error ("cannot suspend a shell without job control");
  95       return (EXECUTION_FAILURE);
  96     }
  97
  98   if (force == 0)
  99     {
 100       no_args (list);
 101
 102       if (login_shell)
 103         {
 104           builtin_error ("cannot suspend a login shell");
 105           return (EXECUTION_FAILURE);
 106         }
 107     }
 108
 109   old_cont = (SigHandler *)set_signal_handler (SIGCONT, suspend_continue);
 110 #if 0
 111   old_stop = (SigHandler *)set_signal_handler (SIGSTOP, SIG_DFL);
 112 #endif
 113   killpg (shell_pgrp, SIGSTOP);
 114   return (EXECUTION_SUCCESS);
 115 }
 116
 117 #endif /* JOB_CONTROL */