exec

exec [command args ...]
exec [-a name] [-c] [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 only.

Options

-a

Use name for the value of argv[0].

-c

Clear the environment before executing the program.

Examples

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