54 lines
1.4 KiB
C
54 lines
1.4 KiB
C
/* Signal Handlers that Return
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Copyright (C) 1991-2022 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, see <https://www.gnu.org/licenses/>.
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*/
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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/* This flag controls termination of the main loop. */
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volatile sig_atomic_t keep_going = 1;
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/* The signal handler just clears the flag and re-enables itself. */
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void
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catch_alarm (int sig)
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{
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keep_going = 0;
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signal (sig, catch_alarm);
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}
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void
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do_stuff (void)
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{
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puts ("Doing stuff while waiting for alarm....");
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}
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int
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main (void)
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{
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/* Establish a handler for SIGALRM signals. */
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signal (SIGALRM, catch_alarm);
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/* Set an alarm to go off in a little while. */
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alarm (2);
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/* Check the flag once in a while to see when to quit. */
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while (keep_going)
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do_stuff ();
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return EXIT_SUCCESS;
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}
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