This is the AT&T Software Technology ast software download site from AT&T Research. The AT&T AST OpenSource Software Collection provides an overview and Practical Reusable UNIX Software provides a historical perspective. You can join the ast and uwin mailgroups, or monitor the mail archives. There is also an AT&T internal talk. The man page inde…
Clone or download
krader1961 `bin/style all` plus bump to clang-format version
I just ran  `bin/style all` on my development server and was surprised
by the large number of changes. That's because my system now has
clang-format 8.0.0 which finally stops producing output like this for
`switch` blocks just because the statement fits on a single line:

    default: { break; }

It now, more sensibly, formats that as

    default: {

So commit those style changes and bump the minimum acceptable clang
version to 8.0.0.
Latest commit 9b24556 Dec 14, 2018
Type Name Latest commit message Commit time
Failed to load latest commit information.
.copr Fix shellcheck warnings in .copr/ script Aug 27, 2018
.github/ISSUE_TEMPLATE Add non-empty about section in bug report template May 18, 2018
bin `bin/style all` plus bump to clang-format version Dec 14, 2018
etc Augment the IWYU map file for BSD systems Nov 1, 2018
features Disable sigqueue() on WSL Nov 12, 2018
lib/package Remove out of date source archives Dec 10, 2018
packaging Use semantic version numbers in Linux packages Aug 26, 2018
scripts Enable auditing in travis builds Dec 10, 2018
src `bin/style all` plus bump to clang-format version Dec 14, 2018
.clang-format Don't allow slightly over long lines Jan 2, 2018
.cppcheck.rules Implement `bin/style` and `bin/lint` scripts Jan 17, 2018
.cppcheck.suppressions Implement an `eaccess()` fallback Oct 14, 2018
.editorconfig Implement config for clang-format and editors Nov 30, 2017
.gitignore Allow missing expect out and err files Aug 16, 2018
.oclint Disable oclint CollapsibleIfStatements warning Sep 15, 2018
.travis.yml Enable auditing in travis builds Dec 10, 2018 Remove legacy, pre 2012, APIs Nov 5, 2018 Add link to test coverage report in readme Nov 20, 2018
LICENSE Add LICENSE file with text from EPL-1.0 May 17, 2018 Update readme regarding mailing lists Nov 21, 2018
app-compat-travis.yml Fix syntax in application compatibility travis file Sep 11, 2018 Disable sigqueue() on WSL Nov 12, 2018
coverity-travis.yml Update coverity secure token Oct 21, 2018 Remove ASAN workaround Sep 30, 2018
meson_options.txt Remove coshell support Sep 24, 2018


This repository contains the AT&T Software Technology (AST) toolkit from AT&T Research. As of November 2017 the development focus has been shifted to the ksh (or ksh93) command and supporting code required to build it.

The non-ksh code of the AST project is no longer being actively maintained. If you are interested in the non-ksh code see below for details on which branches contain the full AST code base.

The project only supports systems where the compiler and underlying hardware is ASCII compatible. This includes Linux on IBM zSeries but not z/OS. The nascent, incomplete, support for EBCDIC has been removed. See issue #742.

Building Korn shell

Building ksh requires the Meson build system. To build ksh execute these commands from the project root directory:

meson build
ninja -C build

You can add a --prefix flag followed by a path to the meson build command to specify where the binaries and libraries are installed. The default is /usr/local.


The ksh executable, helper libraries and man page can be installed with:

ninja -C build install

Getting KornShell


Latest builds for Red Hat Enterprise Linux (CentOS) and Fedora can be found in Copr.

Latest builds for openSUSE and Ubuntu can be found in OBS.

See full list of distros that ship packages for current development version.





Contributing changes to the source code

See the contributing guidelines for information about code style, unit tests, and other topics of interest to anyone who wants to modify the source.

Coverity Scan

Latest results of coverity scan can be viewed here.

Test Coverage

Latest test coverage report can be viewed here.

Working with the full AST source

Warning: Running test cases through the legacy test script may wipe out your home directory (See #477). This has been fixed in current development version.

Full AST source code is available under the 2012-08-01-master and 2016-01-10-beta branches (see below for more details). Bug fixes to these branches are welcome but they are otherwise under low maintenance.

The full AST code includes many tools and libraries, like KSH, NMAKE, SFIO, VMALLOC, VCODEX, etc. It also includes efficient replacements for a lot of the POSIX tools. It was designed to be portable across many UNIX systems and also works under UWIN on Microsoft Windows (see UWIN repo on GitHub under att/uwin).

This software is used to build itself, using NMAKE. After cloning this repo, cd to the top directory of it and run:

./bin/package make

NOTE: That build command only applies to the legacy branches that include the entire AST source. It does not apply to the current master branch that is focused solely on the ksh command and uses the Meson build system.

Almost all the tools in this package (including the bin/package script) are self-documenting; run --man (or --html) for the man page for the tool.

(If you were used to the old AST packaging mechanism, on, this repo is equivalent to downloading the INIT and ast-open packages and running: ./bin/package read on them).


The master branch contains the current development version of ksh93. It only contains source code for ksh93 and the libraries required to build it.

The 2012-08-01-master branch contains the last stable release of full AST source code. It contains one cherry-picked change to allow building on Linux.

The 2016-01-10-beta branch contains the last beta release of full AST source code plus a number of patches that were later added on top of it. Changes for the legacy AST project are normally merged to this branch.

The gh-pages branch will probably be removed. It contains files needed to generate the static AST project page hosted by GitHub. See for more info.


This section needs more detail and clarity. The original README document said the following:

Each package is covered by one of the license files


where is the license type for the package. At the top of each license file is a URL; the license covers all software that refers to this URL. For details run

bin/package license []

Any archives, distributions or packages made from source or binaries covered by license(s) must contain the corresponding license file(s).

Contact Us

The primary mechanism for interacting with this project is the GitHub project by opening issues and pull-requests and watching the project.


Use #ksh channel on freenode to discuss about AT&T KornShell and related variants.


ksh93/users is the Gitter chatroom for AT&T KornShell users.

Mailing lists

Archives of the AST mailing lists (which is mostly about ksh) are available at: and

As of 2018-11-01 the AT&T hosted mailing lists no longer respond to email. Note that the precise date the mailing lists stopped working is unknown. That was simply the date it came to our attention. The last known message to both mailing lists was sent on 2018-03-15. Ironically, since you can't unsubscribe, they still send monthly reminders that you are subscribed.