55 lines
947 B
C
55 lines
947 B
C
#include <signal.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <time.h>
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#include <errno.h>
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void catcher(int sig) {
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printf("Signal catcher called for signal %d\n", sig);
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}
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void timestamp(char *str) {
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time_t t;
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time(&t);
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printf("The time %s is %s", str, ctime(&t));
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}
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int main(int argc, char *argv[]) {
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int result = 0;
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int err = 0;
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struct sigaction sigact;
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sigset_t waitset;
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int sig;
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sigemptyset(&sigact.sa_mask);
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sigact.sa_flags = 0;
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sigact.sa_handler = catcher;
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sigaction(SIGALRM, &sigact, NULL);
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sigemptyset(&waitset);
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sigaddset(&waitset, SIGALRM);
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sigprocmask(SIG_BLOCK, &waitset, NULL);
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alarm(3);
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timestamp("before sigwait()");
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result = sigwait(&waitset, &sig);
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err = errno;
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timestamp("after sigwait()");
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if(result == 0){
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printf("sigwait() returned for signal %d\n", sig);
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return 0;
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}
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printf("sigwait() returned %d; errno = %d\n", result, err);
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perror("sigwait() function failed");
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return 1;
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}
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