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)