W. Richard Stevens indicates in "Advanced Programming in the UNIX Environment"
that fork and exec use COW (copy on write) to allow the parent's and child's
memory to be shared so as to avoid a complete memory copy (page 189).
During my investigation I have found that fork/exec still require at least
the same amount of available virtual memory as the parent process.
I have also found that system() does not seem to require this.
1) What are the differences between the fork/exec method and the system
Is it just that system uses vfork? Are there other subtle
2) How much memory does system() require? (Not including mem for the *cmd).
3) What else should I know about these calls?
4) What are the platform/OS version differences that I should know?
5) Where can I find a good resource about this?