Options (Learning the Korn Shell, 2nd Edition) B.6. Options These are options that can be turned on with the set -o command. All are initially off except where noted. Abbreviations, where listed, are options to set that can be used instead of the full set -o command (e.g., set -a is an abbreviation for set -o allexport). For the most part, the abbreviations are actually backward-compatible Bourne shell options. To disable an option, use set +o long-name or set +X, where long-name and X are the long form or the single character form of the option, respectively. Option Abbrev Meaning allexport -a Export all subsequently defined variables. bgnice   Run all background jobs at decreased priority (on by default). emacs   Use Emacs-style command-line editing. errexit -e Exit the shell when a command exits with nonzero status. gmacs   Use Emacs-style command-line editing, but with a slightly different meaning for CTRL-T (See Chapter 2). ignoreeof   Disallow CTRL-D to exit the shell. keyword -k Execute assignments in the middle of command lines. (Very obsolete.) markdirs   Add / to all directory names generated from wildcard expansion. monitor -m Enable job control (on by default). noclobber -C Don't allow > redirection to existing files. noexec -n Read commands and check for syntax errors, but don't execute them. noglob -f Disable wildcard expansion. nolog   Disable command history for function definitions. notify -b Print job completion messages right away, instead of waiting for next prompt. nounset -u Treat undefined variables as errors, not as null. pipefail   Wait for all jobs in a pipeline to complete. Exit status is that of last command that failed, or zero otherwise. (ksh93g and later.) privileged -p Script is running in suid mode. trackall -h Create an alias for each full pathname found in a command search. (ksh93 ignores this option; the behavior is always on, even if this option is turned off.) verbose -v Print commands (verbatim) before running them. vi   Use vi-style command-line editing. viraw   Use vi-mode and have each keystroke take effect immediately. (This is required on some very old systems for vi-mode to work at all, and is necessary on all systems in order to use TAB for completion. Starting with ksh93n, it is automatically enabled when vi-mode is being used.) xtrace -x Print commands (after expansions) before running them. The set command has a few additional options that don't have corresponding set -o versions, as follows: Option Meaning set -A ... Indexed array assignment. set -s Sort the positional parameters. set -t Read and execute one command, and then exit. (Obsolete.) B.5. Test OperatorsB.7. Typeset Options Copyright © 2003 O'Reilly & Associates. All rights reserved.