NAME

       setuid - run a command with a different uid.

SYNOPSIS

       setuid username|uid   command [ args ]

DESCRIPTION

       Setuid changes user id, then executes the specified command.  Unlike some versions of su(1), this program
       doesn't  ever  ask for a password when executed with effective uid=root.  This program doesn't change the
       environment; it only changes the uid and then uses execvp() to find the command in the path, and  execute
       it.  (If the command is a script, execvp() passes the command name to /bin/sh for processing.)

       For example,
              setuid  some_user  $SHELL
       can be used to start a shell running as another user.

       Setuid  is useful inside scripts that are being run by a setuid-root user — such as a script invoked with
       super, so that the script can execute some commands using the uid of the original user, instead of  root.
       This  allows  unsafe  commands  (such as editors and pagers) to be used in a non-root mode inside a super
       script.  For example, an operator with permission to modify a certain protected_file could  use  a  super
       command that simply does:
              cp protected_file temp_file
              setuid $ORIG_USER ${EDITOR:-/bin/vi} temp_file
              cp temp_file protected_file
       (Note:  don't  use  this  example directly.  If the temp_file can somehow be replaced by another user, as
       might be the case if it's kept in a temporary directory, there will be  a  race  condition  in  the  time
       between editing the temporary file and copying it back to the protected file.)

AUTHOR

       Will Deich

                                                      local                                            SETUID(1)