\section exec exec - execute command in current process
\subsection exec-synopsis Synopsis
exec COMMAND [OPTIONS...]
\subsection exec-description Description
\c exec replaces the currently running shell with a new command.
On successful completion, \c exec never returns. \c exec cannot be used
inside a pipeline.
\subsection exec-example Example
exec emacs starts up the emacs text editor, and exits \c fish.
When emacs exits, the session will terminate.