exec
[
command
]
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.
trap 'exec 2>&-' 0
Close standard error when
shell script exits (signal 0).
$
exec /bin/csh
Replace Bourne shell with C shell.
$
exec < infile
Reassign standard input to infile.