80 lines
1.7 KiB
C
80 lines
1.7 KiB
C
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/* This file is part of the sample code and exercises
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* used by the class "Advanced Programming in the UNIX
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* Environment" taught by Jan Schaumann
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* <jschauma@netmeister.org> at Stevens Institute of
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* Technology.
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*
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* This file is in the public domain.
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*
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* You don't have to, but if you feel like
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* acknowledging where you got this code, you may
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* reference me by name, email address, or point
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* people to the course website:
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* https://stevens.netmeister.org/631/
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*/
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/* A simple illustration of exit handlers. Note that exit handlers are
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* pushed onto a stack and thus execute in reverse order.
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*
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* Illustrate exiting at different times by invoking
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* this program as
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* ./a.out exit handlers invoked after return from main
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* ./a.out 1 exit handlers invoked from within func
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* ./a.out 1 2 no exit handlers invoked
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* ./a.out 1 2 3 we call abort(3), no exit handlers invoked
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*
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*
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* */
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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void
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my_exit1(void) {
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(void)printf("first exit handler\n");
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}
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void
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my_exit2(void) {
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(void)printf("second exit handler\n");
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}
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void
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func(int argc) {
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(void)printf("In func.\n");
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if (argc == 2) {
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exit(EXIT_SUCCESS);
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} else if (argc == 3) {
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_exit(EXIT_SUCCESS);
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} else if (argc == 4) {
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abort();
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}
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}
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int
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main(int argc, char **argv) {
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(void)argv;
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if (atexit(my_exit2) != 0) {
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perror("can't register my_exit2\n");
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exit(EXIT_FAILURE);
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}
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if (atexit(my_exit1) != 0) {
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perror("can't register my_exit1");
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exit(EXIT_FAILURE);
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}
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if (atexit(my_exit1) != 0) {
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perror("can't register my_exit1");
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exit(EXIT_FAILURE);
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}
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func(argc);
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(void)printf("main is done\n");
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return EXIT_SUCCESS;
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}
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