UlfNorell/version

This is a utility program for switching between different versions of a program. It works by managing a set of symlinks for each program. The definition of what links to create for a program, and what versions of the program are installed on the system is called a bundle.

Bundle files go in $HOME/.version and the file name is the name of the bundle. Each file consists of two sections: [package] and [versions]. The package section defines the files and directories that make up the bundle, where they should be installed, and how to compute the location of a particular version. The versions section defines the available versions.

Example (~/.version/gcc):

[package]
prefix: /usr/local/bin
files: gcc, g++
source:
  /usr/local/bin/${TARGET}-${TAG}
  ${SOURCE}/${TARGET}

[versions]
clang /usr/bin
4.9
8

The package section contains three entries:

• prefix: root directory for the symlinks
• files: a comma-separated list of paths (relative to the prefix) of the symlinks to create
• source: a list of locations (one per line) where to find a particular version. These paths can use the following variables
  • ${TAG} - the name of the version
  • ${TARGET} - the relative path listed in files
  • ${SOURCE} - the optional source annotation given after the tag in the version entry
  • ${HOME} - the user's home directory When installing a version a symlink is created to the first source entry that is an existing file or directory.

The version section contains a list of versions, one per line, consisting of a tag (${TAG}) and an optional source annotation (${SOURCE}).

In the example we would get the following mappings (assuming /usr/local/bin/gcc-clang and /usr/local/bin/g++-clang do not exist):

version gcc clang
  /usr/local/bin/gcc -> /usr/bin/gcc
  /usr/local/bin/g++ -> /usr/bin/g++
version gcc 4.9
  /usr/local/bin/gcc -> /usr/local/bin/gcc-4.9
  /usr/local/bin/g++ -> /usr/local/bin/g++-4.9
version gcc 8
  /usr/local/bin/gcc -> /usr/local/bin/gcc-8
  /usr/local/bin/g++ -> /usr/local/bin/g++-8