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.
Use name for the value of argv.
Clear the environment before executing the program.
Place a minus sign at the front of argv, just as login(1) does.
trap 'exec 2>&-' 0Close standard error when shell script exits (signal 0) $
exec /bin/cshReplace shell with C shell $
exec < infileReassign standard input to infile