57 lines
1.2 KiB
C
57 lines
1.2 KiB
C
#include <unistd.h>
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#include <sys/types.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <errno.h>
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int
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main(int argc, char **argv)
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{
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pid_t pid;
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int p[2], ppgrp, opgrp, npgrp;
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char c = '?';
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if (pipe(p) != 0){
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perror("pipe() error");
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exit(EXIT_FAILURE);
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}
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ppgrp = getpgrp();
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printf("parent's pid %d; process group id %d\n", getpid(), ppgrp);
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if ((pid = fork()) == 0) {
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opgrp = getpgrp();
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printf("child's pid %d; process group id %d\n", getpid(), opgrp);
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if(setsid() == -1){
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write(p[1], "e", 1);
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perror("FAIL: setsid");
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exit(EXIT_FAILURE);
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}
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write(p[1], &c, 1);
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npgrp = getpgrp();
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if(opgrp == npgrp){
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printf("FAIL: setsid did not changed child's process group id\n");
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exit(EXIT_FAILURE);
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}
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printf("child's process group id is now %d\n", npgrp);
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sleep(5);
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exit(EXIT_SUCCESS);
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} else {
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read(p[0], &c, 1);
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sleep(3);
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if(c == 'e')
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exit(EXIT_FAILURE);
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if(ppgrp != getpgrp()){
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printf("FAIL: parent's process group id changed from %d to %d\n", ppgrp, getpgrp());
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exit(EXIT_FAILURE);
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}
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#ifndef WITH_SIGCHLD
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npgrp = getsid(pid);
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if(npgrp == ppgrp){
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printf("FAIL: parent's getsid(%d) returned old process group id that should be changed\n", pid);
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exit(EXIT_FAILURE);
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}
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#endif
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exit(EXIT_SUCCESS);
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}
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}
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