How can I exec either a shell script or an executable?

Question

This is a school project I'm working on.

I'm writing a web server. If the requested resource has the extension 'cgi', I need to fork and exec the program. If the cgi is a compiled executable, this works:

execl(path, (char*) 0);

But if the cgi program is a script that needs to be interpreted, I need to do something like this:

execl("/bin/sh", path, path, (char*) 0);

How can I write my code so it will handle either scenario? How does my shell do this? Should I use the file program to determine if it's an executable or text, and if it's text, then assume it needs to be interpreted?

Answer 1

Why do you need to invoke "/bin/sh" explicitly if it's a script?

As long as the script has execute permission and the proper shebang at the top, you should be able to execute it just as if it were an executable.