Re: how is "exec" executed by a shell?

[Jim Bauer <jfbauer@xxxxxxx>]

On Friday 07 January 2005 08:22, Mandeep Sandhu wrote:
> a simple "man" on the shell wud cause the shell to fork a new
> process...cal exec to load "man's" code into the addr. space to
> start execution and "wait" (not sure of this!) for this child (i.e
> man here) to finish....right? does the shell handle calling "exec"
> from the prompt differently?!?

$ man

The shell will do a fork() and the child will do an exec(man).
The parent will wait for the child to finish

$ exec man

The shell will do an exec(man) -- the shell is gone.

$ exec man &

The shell will run "exec man" in the background.
It will call fork() but not wait.
The child will exec(man).
This is not much different from just "man &"



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