Linux get pid of program launched via script with execl

Question

I have a piece of code that launches another program as child process.

pid = execlp("path-to/program", "path-to/program", nullptr);

This returns me the pid of the process i launched so I can access it. Now we need to launch a process via a shell script. Like this:

#!/bin/bash
export LD_LIBRARY_PATH=/path-to/program
/path-to/program
#or:
wine /path-to/program.exe

C++:

pid = execlp("/path-to/shelscript.sh", "/path-to/shellscript.sh", nullptr);

When I now call execl it will return the pid of the shell, not of the launched process. I could check if the the path to the program contains ".sh" and increment the pid by one, but this will not always work. Is there a cleaner & more reliable way to do this?

Answer 1

If you start a process in a shell script, the variable $! contains the pid of the process just created. You could eg output this using echo and start the shell script using popen() and read the pid from there.