80 lines
1.3 KiB
C
80 lines
1.3 KiB
C
#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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int child, cstatus;
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void sigquit() {
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printf("CHILD: got SIGQUIT\n");
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exit(0);
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}
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void sigchld() {
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printf("PARENT: got SIGCHLD\n");
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#ifdef WITH_SIGCHLD
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child = wait(&cstatus);
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if(cstatus == 0)
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exit(0);
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else
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{
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printf("PARENT: child exited with status %d\n", cstatus);
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exit(1);
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}
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#endif
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}
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int
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main() {
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int pid, p[2];
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char dummy[1];
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/* get child process */
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if(pipe(p)){
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perror("pipe");
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exit(1);
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}
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if ((pid = fork()) < 0) {
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perror("fork");
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exit(2);
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}
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if (pid == 0) {
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printf("%d is the new child!\n", getpid());
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signal(SIGHUP, SIG_IGN);
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signal(SIGQUIT, sigquit);
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printf("Child wait in blocking syscall...\n");
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read(p[0], &dummy, 1);
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/* reached only if the ignored SIGHUP interrupts the read */
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printf("Child interrupted by ignored signal\n");
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exit(5);
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}
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else /* parent */
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{
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signal(SIGCHLD,sigchld);
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sleep(3);
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printf("PARENT: sending SIGHUP\n");
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kill(pid,SIGHUP);
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sleep(3); /* pause for 3 secs */
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printf("PARENT: sending SIGQUIT\n");
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kill(pid,SIGQUIT);
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#ifdef WITH_SIGCHLD
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sleep(10000);
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exit(1);
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#else
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child = wait(&cstatus);
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if(child == pid && cstatus == 0)
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exit(0);
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else
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{
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printf("PARENT: child exited with status %d\n", cstatus);
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exit(1);
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}
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#endif
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}
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}
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