Bash/Optional-Features

10.8 Optional Features

The Bash configure has a number of --enable-feature options, where feature indicates an optional part of Bash. There are also several --with-package options, where package is something like ‘bash-malloc’ or ‘purify’. To turn off the default use of a package, use --without-package. To configure Bash without a feature that is enabled by default, use --disable-feature.

Here is a complete list of the --enable- and --with- options that the Bash configure recognizes.

--with-afs: Define if you are using the Andrew File System from Transarc.
--with-bash-malloc: Use the Bash version of malloc in the directory lib/malloc. This is not the same malloc that appears in GNU libc, but an older version originally derived from the 4.2 BSD malloc. This malloc is very fast, but wastes some space on each allocation. This option is enabled by default. The NOTES file contains a list of systems for which this should be turned off, and configure disables this option automatically for a number of systems.
--with-curses: Use the curses library instead of the termcap library. This should be supplied if your system has an inadequate or incomplete termcap database.
--with-gnu-malloc: A synonym for --with-bash-malloc.
--with-installed-readline[=PREFIX]: Define this to make Bash link with a locally-installed version of Readline rather than the version in lib/readline. This works only with Readline 5.0 and later versions. If PREFIX is yes or not supplied, configure uses the values of the make variables includedir and libdir, which are subdirectories of prefix by default, to find the installed version of Readline if it is not in the standard system include and library directories. If PREFIX is no, Bash links with the version in lib/readline. If PREFIX is set to any other value, configure treats it as a directory pathname and looks for the installed version of Readline in subdirectories of that directory (include files in PREFIX/include and the library in PREFIX/lib).
--with-purify: Define this to use the Purify memory allocation checker from Rational Software.
--enable-minimal-config: This produces a shell with minimal features, close to the historical Bourne shell.

There are several --enable- options that alter how Bash is compiled and linked, rather than changing run-time features.

--enable-largefile: Enable support for large files if the operating system requires special compiler options to build programs which can access large files. This is enabled by default, if the operating system provides large file support.
--enable-profiling: This builds a Bash binary that produces profiling information to be processed by gprof each time it is executed.
--enable-static-link: This causes Bash to be linked statically, if gcc is being used. This could be used to build a version to use as root’s shell.

The ‘minimal-config’ option can be used to disable all of the following options, but it is processed first, so individual options may be enabled using ‘enable-feature’.

All of the following options except for ‘disabled-builtins’, ‘direxpand-default’, and ‘xpg-echo-default’ are enabled by default, unless the operating system does not provide the necessary support.

--enable-alias: Allow alias expansion and include the alias and unalias builtins (see Aliases).
--enable-arith-for-command: Include support for the alternate form of the for command that behaves like the C language for statement (see Looping Constructs).
--enable-array-variables: Include support for one-dimensional array shell variables (see Arrays).
--enable-bang-history: Include support for csh-like history substitution (see History Interaction).
--enable-brace-expansion: Include csh-like brace expansion ( b{a,b}c → bac bbc ). See Brace Expansion, for a complete description.
--enable-casemod-attributes: Include support for case-modifying attributes in the declare builtin and assignment statements. Variables with the uppercase attribute, for example, will have their values converted to uppercase upon assignment.
--enable-casemod-expansion: Include support for case-modifying word expansions.
--enable-command-timing: Include support for recognizing time as a reserved word and for displaying timing statistics for the pipeline following time (see Pipelines). This allows pipelines as well as shell builtins and functions to be timed.
--enable-cond-command: Include support for the [[../ conditional command|Conditional Constructs]]).
--enable-cond-regexp: Include support for matching POSIX regular expressions using the ‘=~’ binary operator in the [[../ conditional command|Conditional Constructs]]).
--enable-coprocesses: Include support for coprocesses and the coproc reserved word (see Pipelines).
--enable-debugger: Include support for the bash debugger (distributed separately).
--enable-dev-fd-stat-broken: If calling stat on /dev/fd/N returns different results than calling fstat on file descriptor N, supply this option to enable a workaround. This has implications for conditional commands that test file attributes.
--enable-direxpand-default: Cause the direxpand shell option (see The Shopt Builtin) to be enabled by default when the shell starts. It is normally disabled by default.
--enable-directory-stack: Include support for a csh-like directory stack and the pushd, popd, and dirs builtins (see The Directory Stack).
--enable-disabled-builtins: Allow builtin commands to be invoked via ‘builtin xxx’ even after xxx has been disabled using ‘enable -n xxx’. See Bash Builtins, for details of the builtin and enable builtin commands.
--enable-dparen-arithmetic: Include support for the ((…)) command (see Conditional Constructs).
--enable-extended-glob: Include support for the extended pattern matching features described above under Pattern Matching.
--enable-extended-glob-default: Set the default value of the extglob shell option described above under The Shopt Builtin to be enabled.
--enable-function-import: Include support for importing function definitions exported by another instance of the shell from the environment. This option is enabled by default.
--enable-glob-asciirange-default: Set the default value of the globasciiranges shell option described above under The Shopt Builtin to be enabled. This controls the behavior of character ranges when used in pattern matching bracket expressions.
--enable-help-builtin: Include the help builtin, which displays help on shell builtins and variables (see Bash Builtins).
--enable-history: Include command history and the fc and history builtin commands (see Bash History Facilities).
--enable-job-control: This enables the job control features (see Job Control), if the operating system supports them.
--enable-multibyte: This enables support for multibyte characters if the operating system provides the necessary support.
--enable-net-redirections: This enables the special handling of filenames of the form /dev/tcp/host/port and /dev/udp/host/port when used in redirections (see Redirections).
--enable-process-substitution: This enables process substitution (see Process Substitution) if the operating system provides the necessary support.
--enable-progcomp: Enable the programmable completion facilities (see Programmable Completion). If Readline is not enabled, this option has no effect.
--enable-prompt-string-decoding: Turn on the interpretation of a number of backslash-escaped characters in the $PS0, $PS1, $PS2, and $PS4 prompt strings. See Controlling the Prompt, for a complete list of prompt string escape sequences.
--enable-readline: Include support for command-line editing and history with the Bash version of the Readline library (see Command Line Editing).
--enable-restricted: Include support for a restricted shell. If this is enabled, Bash, when called as rbash, enters a restricted mode. See The Restricted Shell, for a description of restricted mode.
--enable-select: Include the select compound command, which allows the generation of simple menus (see Conditional Constructs).
--enable-separate-helpfiles: Use external files for the documentation displayed by the help builtin instead of storing the text internally.
--enable-single-help-strings: Store the text displayed by the help builtin as a single string for each help topic. This aids in translating the text to different languages. You may need to disable this if your compiler cannot handle very long string literals.
--enable-strict-posix-default: Make Bash POSIX-conformant by default (see Bash POSIX Mode).
--enable-usg-echo-default: A synonym for --enable-xpg-echo-default.
--enable-xpg-echo-default: Make the echo builtin expand backslash-escaped characters by default, without requiring the -e option. This sets the default value of the xpg_echo shell option to on, which makes the Bash echo behave more like the version specified in the Single Unix Specification, version 3. See Bash Builtins, for a description of the escape sequences that echo recognizes.

The file config-top.h contains C Preprocessor ‘#define’ statements for options which are not settable from configure. Some of these are not meant to be changed; beware of the consequences if you do. Read the comments associated with each definition for more information about its effect.