fork() question

MK27 · 09-21-2008, 11:59 AM

why does this:

Code:

#include <stdio.h>

int main() {
        short int pid, i;
        for (i=0; i<=1; i++) {
                pid = fork();
                if (pid==0) printf("hello%d\n",i);
                else printf("pid: %d\n", pid);
                fflush(NULL);
        }   
}

produce this:

Code:

hello0
hello1
pid: 4790
pid: 4789
hello1
pid: 4791

esp. this red bit...

robwhit · 09-21-2008, 12:06 PM

fork returns a pid_t, not a short int. To print a short int, use %hd. #include <unistd.h> for fork.

>fflush(NULL);

*sad face*

**Salem** · 09-21-2008, 12:10 PM

The first child process doesn't exit, so it too runs a loop with i = 1

09-21-2008, 11:59 AM	#1
MK27 subminimalist Join Date: Jul 2008 Location: NYC Posts: 3,946	fork() question why does this: Code: #include <stdio.h> int main() { short int pid, i; for (i=0; i<=1; i++) { pid = fork(); if (pid==0) printf("hello%d\n",i); else printf("pid: %d\n", pid); fflush(NULL); } } produce this: Code: hello0 hello1 pid: 4790 pid: 4789 hello1 pid: 4791 esp. this red bit... __________________ Accuracy and integrity mean nothing if you don't make it past the censors...PYTHAGORAS
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09-21-2008, 12:06 PM	#2
robwhit Registered User Join Date: Oct 2001 Posts: 2,110	fork returns a pid_t, not a short int. To print a short int, use %hd. #include <unistd.h> for fork. >fflush(NULL); sad face
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09-21-2008, 12:10 PM	#3
Salem and the hat of vanishing Join Date: Aug 2001 Location: The edge of the known universe Posts: 21,214	The first child process doesn't exit, so it too runs a loop with i = 1 __________________ If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut. Up to 8Mb PlusNet broadband from only £5.99 a month!
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