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/*
CSci 4061 - Recitation 2 - 21st Sept 2020
Breakout 1
An iditoic loner's lone attempt
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <errno.h>
int main(int argc, char **argv) {
// take 'n' from the input and convert to integer
// hint: see cmd slide
if (argc < 2) {
printf("USAGE: ./main int\n");
return -1;
}
int n = strtol(argv[1], NULL, 10);
// for i in n
// create child process
// print pid //hint: check week 2 slides
// call execl to print 'hello there' using 'echo' //hint: check recitation slide
pid_t pid;
for (int i=0; i<n; i++) {
pid = fork();
if (pid != 0) {
printf("%d\n", getpid());
execl("/bin/echo", "/bin/echo", "hello", "there", NULL);
}
}
// parent waits for all child processes to terminate
for (int i=0; i<n; i++) {
wait(NULL);
}
// parent create child process
// call execv on 'ptime' executable // hint: similar to 'echo' usage in slide
pid = fork();
if (pid != 0) {
char *args[] = {"./ptime", NULL};
execv(*args, args);
}
// parent waits for child to complete
waitpid(pid, NULL, 0);
return 0;
}
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