Mac OS X Panther in a Nutshell, 2nd Edition

Name

exec

Synopsis

                     exec [options] [command]

Execute command in place of the current shell (instead of creating a new process). exec is also useful for opening, closing, or copying file descriptors.

Options

-a name

Tell command that it was invoked as name.

-c

Remove all environment variables from the process when the new command runs.

-l

Treat the new process as if the user were logging in.

Examples

$ trap 'exec 2>&-' 0   
                     Close standard error when shell script exits (signal 0)
$ exec /bin/tcsh       
                     Replace current shell with extended C shell
$ exec < infile        
                     Reassign standard input to infile