Korn Shell Programming by Example

exec

Official Description

If an argument is given, the command specified by the argument is executed in place of this shell without creating a new process.

Syntax

exec [argument ...]

Options

-c clears variables before execution.

-a assigns a different name to the command being run.

Oddities

Options -a and -c are available in ksh93 and beyond.

If no arguments are given, the effect of this command is to modify file descriptors through redirection.

File descriptors > 2 opened with exec are closed when the shell exits.

Example

 $ ksh # Create new ksh $ $ print $$ # Display pid 4088 $ $ exec csh # Use exec to run a different shell % %echo $$ # Note pid is the same 4088 % %ksh # Run a different shell without using exec $ $ print $$ # Note different ...