quit.h

   1 /* quit.h -- How to handle SIGINT gracefully. */
   2
   3 /* Copyright (C) 1993-2013 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bash, the Bourne Again SHell.
   6
   7    Bash is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    Bash is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #if !defined (_QUIT_H_)
  22 #define _QUIT_H_
  23
  24 #include "sig.h"        /* for sig_atomic_t */
  25
  26 /* Non-zero means SIGINT has already occurred. */
  27 extern volatile sig_atomic_t interrupt_state;
  28 extern volatile sig_atomic_t terminating_signal;
  29
  30 /* Macro to call a great deal.  SIGINT just sets the interrupt_state variable.
  31    When it is safe, put QUIT in the code, and the "interrupt" will take
  32    place.  The same scheme is used for terminating signals (e.g., SIGHUP)
  33    and the terminating_signal variable.  That calls a function which will
  34    end up exiting the shell. */
  35 #define QUIT \
  36   do { \
  37     if (terminating_signal) termsig_handler (terminating_signal); \
  38     if (interrupt_state) throw_to_top_level (); \
  39   } while (0)
  40
  41 #define CHECK_ALRM \
  42   do { \
  43     if (sigalrm_seen) \
  44       longjmp (alrmbuf, 1); \
  45   } while (0)
  46
  47 #define SETINTERRUPT interrupt_state = 1
  48 #define CLRINTERRUPT interrupt_state = 0
  49
  50 #define ADDINTERRUPT interrupt_state++
  51 #define DELINTERRUPT interrupt_state--
  52
  53 /* The same sort of thing, this time just for signals that would ordinarily
  54    cause the shell to terminate. */
  55
  56 #define CHECK_TERMSIG \
  57   do { \
  58     if (terminating_signal) termsig_handler (terminating_signal); \
  59   } while (0)
  60
  61 #define LASTSIG() \
  62   (terminating_signal ? terminating_signal : (interrupt_state ? SIGINT : 0))
  63
  64 #define CHECK_WAIT_INTR \
  65   do { \
  66     if (wait_signal_received && this_shell_builtin && (this_shell_builtin == wait_builtin)) \
  67       longjmp (wait_intr_buf, 1); \
  68   } while (0)
  69
  70 #define RESET_SIGTERM \
  71   do { \
  72     sigterm_received = 0; \
  73   } while (0)
  74
  75 #define CHECK_SIGTERM \
  76   do { \
  77     if (sigterm_received) termsig_handler (SIGTERM); \
  78   } while (0)
  79 #endif /* _QUIT_H_ */