68 lines
1.3 KiB
C
68 lines
1.3 KiB
C
#include <errno.h>
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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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#include <signal.h>
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#include <sys/wait.h>
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void sighup() {
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signal(SIGHUP,sighup); /* reset signal */
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printf("CHILD: SIGHUP received\n");
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}
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int
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main(int argc, char *argv[])
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{
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pid_t cpid, w;
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int ret, status;
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cpid = fork();
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if(cpid == -1){
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perror("fork");
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exit(EXIT_FAILURE);
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}
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if (cpid == 0) { /* Code executed by child */
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signal(SIGHUP, sighup); /* set function calls */
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printf("Child PID is %ld, calling pause()...\n", (long) getpid());
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ret = pause();
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if(ret == -1 && errno == EINTR){
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printf("Pause returned %d with errno = EINTR\n", ret);
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_exit(0);
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}
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if(ret != -1)
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printf("Pause returned %d\n", ret);
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if(errno != EINTR)
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printf("Pause returned but errno != EINTR\n");
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_exit(1);
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}
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/* Code executed by parent */
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sleep(5);
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kill(cpid, SIGHUP);
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do {
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w = waitpid(cpid, &status, WUNTRACED);
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if (w == -1) {
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perror("waitpid");
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exit(EXIT_FAILURE);
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}
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if (WIFEXITED(status)) {
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printf("exited, status=%d\n", WEXITSTATUS(status));
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} else if (WIFSIGNALED(status)) {
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printf("killed by signal %d\n", WTERMSIG(status));
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exit(EXIT_FAILURE);
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} else if (WIFSTOPPED(status)) {
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printf("stopped by signal %d\n", WSTOPSIG(status));
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exit(EXIT_FAILURE);
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}
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} while (!WIFEXITED(status) && !WIFSIGNALED(status));
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exit(EXIT_SUCCESS);
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}
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