between fork, exec, & system

[debkumar]

Somewhere I saw a question saying
"Whats the difference between fork, exec, & system commands"

Can anyone answer me the above question?

Thanks in advance
Deb

[nspils]

Are you looking for the use of these terms in C++, Java, or in Unix?

[Danny]

it's a huge topic, but in essence, fork creates a child process which is clone of the parent process: it has the same memory image, credentials, open files etc.

exec creates a new process that is usually a different program. The precise details depend of course on the specific variant called.

system() is a syscall that launches a new process and takes an executable file as its only argument. It doesn't communicate with the parent process in any other way.