INSTALL.txt

Building and Installing OSH
===========================

OSH is a bash-compatible shell, and is part of the Oil project
(http://www.oilshell.org).

This file describes how to install OSH.  (It's in the release tarball and also
published on the web.)

Quick Start
-----------

If you haven't already done so, extract the tarball:
 
    tar -x --xz < oil-0.6.pre16.tar.xz
    cd oil-0.6.pre16

Either install as /usr/local/bin/osh:

    ./configure      # completes very quickly
    make             # 30-60 seconds
    sudo ./install

or install as ~/bin/osh:

    ./configure --prefix ~
    make
    ./install

The latter doesn't require root access, but it requires ~/bin to be in your
PATH.

NOTE: Out-of-tree builds are NOT currently supported, so you have to be in the
oil-0.6.pre16 directory.

Smoke Test
----------

OSH behaves like a POSIX shell:

    $ osh -c 'echo hi'
    hi

This parses and prints a syntax tree for the 'configure' script.

    osh -n configure

System Requirements
-------------------

Roughly speaking, you need:

  - an ANSI C environment (compiler and libc)
  - GNU Bash
  - GNU Make.

(I want to eventually remove the GNU requirements and require just POSIX sh
instead).

Optional:

  - GNU readline library, for interactive features
    (https://cnswww.cns.cwru.edu/php/chet/readline/rltop.html)

Debian/Ubuntu and derivatives:

    sudo apt install build-essential libreadline-dev

Alpine Linux:

    apk add libc-dev gcc bash make readline-dev

OSH hasn't been tested on non-Linux systems, but eventually it should run on
any POSIX-compatible system.

Build Options
-------------

./configure --help will show the options.  Right now, the only significant
options are --prefix and --{with,without}-readline.

Notes
-----

- The oil executable behaves like busybox, and osh is a symlink to it.  Compare
  oil --help vs. osh --help.
- OSH uses a slight fork of the Python 2.7 runtime, so it should
  compile with most popular compiler/OS combinations.

TODO
----

- Add back build support for PGO and LTO and document them.  (CPython has
  this.)