(features.info)The Set Builtin

The Set Builtin
===============

   This builtin is so overloaded that it deserves its own section.

`set'
          set [-abefhkmnptuvxldCHP] [-o OPTION] [ARGUMENT ...]

    `-a'
          Mark variables which are modified or created for export.

    `-b'
          Cause the status of terminated background jobs to be reported
          immediately, rather than before printing the next primary
          prompt.

    `-e'
          Exit immediately if a command exits with a non-zero status.

    `-f'
          Disable file name generation (globbing).

    `-h'
          Locate and remember (hash) commands as functions are defined,
          rather than when the function is executed.

    `-k'
          All keyword arguments are placed in the environment for a
          command, not just those that precede the command name.

    `-m'
          Job control is enabled (Note: Job Control.).

    `-n'
          Read commands but do not execute them.

    `-o OPTION-NAME'
          Set the flag corresponding to OPTION-NAME:

         `allexport'
               same as `-a'.

         `braceexpand'
               the shell will perform brace expansion (Note: Brace
               Expansion.).

         `emacs'
               use an emacs-style line editing interface (Note: Command
               Line Editing.).

         `errexit'
               same as `-e'.

         `histexpand'
               same as `-H'.

         `ignoreeof'
               the shell will not exit upon reading EOF.

         `interactive-comments'
               allow a word beginning with a `#' to cause that word and
               all remaining characters on that line to be ignored in an
               interactive shell.

         `monitor'
               same as `-m'.

         `noclobber'
               same as `-C'.

         `noexec'
               same as `-n'.

         `noglob'
               same as `-f'.

         `nohash'
               same as `-d'.

         `notify'
               same as `-b'.

         `nounset'
               same as `-u'.

         `physical'
               same as `-P'.

         `posix'
               change the behavior of Bash where the default operation
               differs from the Posix 1003.2 standard to match the
               standard.  This is intended to make Bash behave as a
               strict superset of that standard.

         `privileged'
               same as `-p'.

         `verbose'
               same as `-v'.

         `vi'
               use a `vi'-style line editing interface.

         `xtrace'
               same as `-x'.

    `-p'
          Turn on privileged mode.  In this mode, the `$ENV' file is
          not processed, and shell functions are not inherited from the
          environment.  This is enabled automatically on startup if the
          effective user (group) id is not equal to the real user
          (group) id.  Turning this option off causes the effective user
          and group ids to be set to the real user and group ids.

    `-t'
          Exit after reading and executing one command.

    `-u'
          Treat unset variables as an error when substituting.

    `-v'
          Print shell input lines as they are read.

    `-x'
          Print commands and their arguments as they are executed.

    `-l'
          Save and restore the binding of the NAME in a `for' command.

    `-d'
          Disable the hashing of commands that are looked up for
          execution.  Normally, commands are remembered in a hash
          table, and once found, do not have to be looked up again.

    `-C'
          Disallow output redirection to existing files.

    `-H'
          Enable ! style history substitution.  This flag is on by
          default.

    `-P'
          If set, do not follow symbolic links when performing commands
          such as `cd' which change the current directory.  The
          physical directory is used instead.

    `--'
          If no arguments follow this flag, then the positional
          parameters are unset.  Otherwise, the positional parameters
          are set to the ARGUMENTS, even if some of them begin with a
          `-'.

    `-'
          Signal the end of options, cause all remaining ARGUMENTS to
          be assigned to the positional parameters.  The `-x' and `-v'
          options are turned off.  If there are no arguments, the
          positional parameters remain unchanged.

     Using `+' rather than `-' causes these flags to be turned off.
     The flags can also be used upon invocation of the shell.  The
     current set of flags may be found in `$-'.  The remaining N
     ARGUMENTS are positional parameters and are assigned, in order, to
     `$1', `$2', ..  `$N'.  If no arguments are given, all shell
     variables are printed.