Efficient way to read exit codes (popen, system, exec...?) 1

[LenRI]

I'm calling a little C program (let's say PorgA) I wrote from a C++ application (call this one ProgB) which I am in the process of writing. I know I can talk between them by other means (signals, pipes, sockets, etc...), but I am simply trying to read the exit code of ProgA after calling it from ProgB. What would be in your opinion the best way to accomplish this. Mind you I not only need to get the exit code, but also the PID of ProgA whenever I launch it.

Thanks for your help.

Len

 

[Salem]

Which OS/Compiler do you have?

Because something like

int status = system("myprogA");

Will work in Linux, but won't work for some windows compilers.

Since you mention PID, I'll guess Linux or Unix.
The way to get the PID and the exit status in these operating systems is something like this

pid_t pid = fork();
if ( pid == 0 ) {
  // running in child process, replace it with progA
  char *argv[] = { "./progA", NULL };
  execv( argv[0], argv );
} else {
  // running in parent, wait for progA to complete
  // and return its exit status.
  int status;
  waitpid( pid, &status, 0 );
  printf("Child %d exited with status %d\n", pid, status );
}

--

 

[LenRI]

Thank you very much. This is exactly what I was trying to accomplish. By the way, it is on Linux.