Is std::system or exec better practice?

Question

I have a program that calls a shell script tool that I made that goes through a directory and zips up files and gets the checksum value and calls some other tools to upload the files. The operation takes roughly 3 to 4 minutes.

I call the script like this:

int result = system("/bin/sh /path/to/my/script");

I've also got the same result by using the exec() family of functions:

int child = fork();
if(child == 0) {
    execl( "/bin/sh", "sh", "/path/to/my/script", (char*)0 );
}

I know with exec you can redirect output to the parent program so it can read the output of the command line tools, but other than that when should you use system as opposed to exec?

Answer 1

Ignoring for the time being that use of system is portable while use of exec family of functions is not portable...

When you combine use of exec family of functions with other POSIX functions such as pipe, dup, wait, you get a lot more control over how to pass data between the parent process and the child process.

When you don't need any of those controls, i.e. you just want to execute a command, then using system is preferable, IMO.