c code vs shell script?

khucinx · 05-12-2004, 05:44 PM

i have c code ( test.c ) like :

#include<stdio.h>
#include<unistd.h>
int main()
{
execl ("/bin/csh", "csh", "-c", "./coba", (char *)0);
printf("succes\n");
return 0;
}

in the same directory, i have shell script (coba) too :

#!/bin/sh
ls

when i run c code ( by type ./test ), the output are file and directory :
ahmad/
test.c
test
coba
but "succes" is not printed in terminal. how can i print "succes" from code above?

Hko · 05-12-2004, 06:06 PM

execl() replaces the current process (which is your program) with the program passed to execl(). In your case /bin/csh.

So after execl() your program does not run anymore, because it was replaced by /bin/csh. So the printf() line is never reached.

To solve this, use system() instead, with start a new process, then waits for it to exit, return to your program. Using system(), the program is even simpler:

Code:

#include <stdio.h>
#include <stdlib.h>

int main()
{
	 system("/bin/csh -c ./coba");
	 printf("succes\n");
	 return 0;
}

Note that:
#include <unistd.h> is replaced by
#include <stdlib.h>