Unix in a Nutshell, 4th Edition

Name

exec

Synopsis

    exec [command args ...]
    exec [-a name] [-cl] [command args ... ]

Execute command in place of the current process (instead of creating a new process). exec is also useful for opening, closing, or copying file descriptors. The second form is for ksh93 and Bash.

Options

-a

Use name for the value of argv[0].

-c

Clear the environment before executing the program.

-l

Place a minus sign at the front of argv[0], just as login(1) does. Bash only.

Examples

trap 'exec 2>&-' 0              Close standard error when
                                    shell script exits (signal 0)

    $ exec /bin/csh                 
                     Replace shell with C shell
    $ exec < infileReassign standard input to infile