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/* test 4 */
#include <sys/types.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
pid_t pid0, pid1, pid2, pid3;
int s, i, fd, nextb;
char *tempfile = "test4.temp";
char buf[1024];
int max_error = 2;
#include "common.h"
int main(void);
void subr(void);
void nofork(void);
void quit(void);
int main()
{
int k;
start(4);
creat(tempfile, 0777);
for (k = 0; k < 20; k++) {
subr();
}
unlink(tempfile);
quit();
return(-1); /* impossible */
}
void subr()
{
if ( (pid0 = fork()) != 0) {
/* Parent 0 */
if (pid0 < 0) nofork();
if ( (pid1 = fork()) != 0) {
/* Parent 1 */
if (pid1 < 0) nofork();
if ( (pid2 = fork()) != 0) {
/* Parent 2 */
if (pid2 < 0) nofork();
if ( (pid3 = fork()) != 0) {
/* Parent 3 */
if (pid3 < 0) nofork();
for (i = 0; i < 10000; i++);
kill(pid2, SIGKILL);
kill(pid1, SIGKILL);
kill(pid0, SIGKILL);
wait(&s);
wait(&s);
wait(&s);
wait(&s);
} else {
fd = open(tempfile, O_RDONLY);
lseek(fd, 20480L * nextb, 0);
for (i = 0; i < 10; i++) read(fd, buf, 1024);
nextb++;
close(fd);
exit(0);
}
} else {
while (1) getpid();
}
} else {
while (1) getpid();
}
} else {
while (1) getpid();
}
}
void nofork()
{
int e = errno;
printf("Fork failed: %s (%d)\n",strerror(e),e);
exit(1);
}
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