Programming

Hi,
in my program i need to run an external program in background.I am aware that there are at least 2 alternatives for this:
1)fork+exec
2)system("program &");

I have read several posts about this,and they all tend to suggest to use fork+exec (and that's what i am doing now).
I have some questions though:
a) I read somewhere that "system" actually uses fork+exec (and the man page for "system" implicitly seems to confirm it).Can you confirm this?

b)in the original source code i started working on,the external program was run like this:

Code:

int status=system("program &");
printf("exited with status %d",WEXITSTATUS(status));

I don't think that's correct for ay least 2 reasons:
a)it doesn't check WIFEXITED before checking WEXITSTATUS
b)since i am interested in the exit value of the external program,i think that this code is wrong since it wil output only the "system" exit code,and not the external program's one(consider that the external program will run for a while,so its exit code will be outputted much later).
Am i correct?

Oops i forgot the 3rd question

If i use fork+exec,i get a zombie process when external program exits,which i treat with wait.
This didn't happen when i used "system" to run it.Why?

I would read your man page - the original code is correct - system does return the lower 8 bits (just like you get for wait) of the the exit status code of "process"

system returns -1 if fork() fails, otherwise it returns the exit status.