symin

Symlink installer - a lightweight package manager for installations from sources on UNIX systems.

symin performs different operations on packages, such as install, uninstall, hide, and unhide packages using symlink-style package management. The operations do not need the root privileges and are performed locally under the home directory with a single command.

symin is kept leightweight to make it available on most systems with minimum dependencies.

Sample Usages

First, execute source setup.sh to create the initial directories and configure the library and binary paths. Here you find some sample usages of symin to install, uninstall, hide (making the package temporarily unavailable to the system without uninstalling/destroying it), and unhide packages:

symin --url=https://ftp.gnu.org/gnu/bc/bc-1.07.tar.gz               # install from the URL (archive will be downloaded)
symin --file=bc-1.07.tar.gz                                         # install from the archive file (archive file should be available)
symin --file=gnuplot-5.4.2.tar.gz --config-params="--with-cairo"    # install from the archive and setting the configure parameters
symin --uninstall --name=neovim                                     # uninstall the neovim application (program identified by a part of its name)
symin --uninstall --executable=gnuplot                              # uninstall the gnuplot program (program identified by its executable)
symin --hide --name=python                                          # hides python3 without actually uninstalling it
symin --unhide --name=python                                        # undo hide a hidden application by (a part of) its name  

Notice that symin only supports GNU build system installations (./configure & make & make install) with the optional configure command. If necessary, autogen.sh is performed before ./configure.

Setup

To setup symin you can simply run source setup. More options of the setup script for special cases are as follows:

Usage: source setup.sh [ -p package_path ] [ -r export_root ] [ -i install_path ] [ -j cores ] [ -s installer_path ]

You are good to go with the defaults and just performing source setup.sh. All flags are optional and setup.sh can be invoked without defining any flags. In the case of having specific requirements, please first refer to the section Package Management bellow to understand the setup parameters. The following flags can be adjusted to match with more specific usages.

• -p <package_path>: defines the package path to keep the archive files.
• -r <export_root>: the directory that is exported to the $PATH and $LD_LIBRARY_PATH environment variables.
• -i <install_path>: the directory containing the installed packages in separate directories each.
• -j <cores>: the number of cores for make. This is automatically detected if not specified.
• -s <installer_path>: the path to the symin script.

Using symin

Usage: symin
          [ --install ]                               # installs the specified package (default behavior)
          [ --uninstall ]                             # uninstalls the specified package
          [ --hide ]                                  # hides the specified package as if it is not installed
          [ --unhide ]                                # undo hides the specified package
          [ --url=<download url> ]                    # package download URL
          [ --file=<tar archive> ]                    # package archive file name
          [ --cores=<number of cores> ]               # number of cores to use for build
          [ --config-params=<configure parameters> ]  # parameters to be passed to ./configure
          [ --name=<package name> ]                   # the name of the package (or a part of its name)
          [ --executable=<program executable> ]       # an executable to specify a program for uninstall or hide
          [ --help | -h ]                             # prints this help message

Supported operations are:

install (default): installs a package. to install a package, one of the following parameters must be set: url: the URL to download the package. name: the name (or a part of the name) of an already downloaded package (e.g., when a package is installed and then uninstalled, its archive file is kept). If more than one packages match with the name, the user will choose between the matching candidates. file: the archive file of the package (locally available). optional parameters to install a package are as follows: config-params (optional): parameters that to be passed to the ./configure script. cores (optional): number of cores available to build the package (make -j<cores>).

uninstall: uninstalls a package. To specify a package to be uninstalled, one of the following parameters must be set: executable: an executable of the program to be uninstalled. The program is determined from the executable. name: the name or a part of the name of the package to specify the target package. If more than one packages match with the name, the user will choose between the matching candidates.

hide: makes a package (that is already installed) unavailable as if it's not installed, without actually uninstalling it. This operation hides the package on the system while it is still there safely. symin does not touch the package installation and only removes its symlinks (which can be recreated using unhide). This can be useful for some testing/expertimenting scenarios with the packages. To specify a package for hiding, one of the parameters executable or name must be set (see the discussion under the uninstall operation).

unhide: undo hides a hidden package to be available again on the system. To specify a hidden package, its name must be given. If more than one packages match with the name, the user will choose between the matching candidates.

Package Management

Packages are maintained in three directories:

• package_path: contains all the archive files of the packages in case they are needed in the future.
• export_root: contains the directories that are exported in the $PATH and $LD_LIBRARY_PATH environment variables (in .bashrc).
  • The directories <export_root>/usr/bin and <export_root>/usr/sbin are exported to $PATH.
  • The directories <export_root>/usr/lib and <export_root>/usr/lib64 are exported to $LD_LIBRARY_PATH.
• install_path: the packages are installed here in separate directories for each package. Hence, they can be distinguished easily by their directories. Though, these directories are not exported to the $PATH and $LD_LIBRARY_PATH environment variables.

symin performs the installation of a package package_namein fakeroot:

1. It configures the package to be installed under the export_root/usr/ directory.
   • The package thinks it is going to be installed under export_root/usr/.
2. symin redirects the installation (make install) to install the files under the install_path/package_name directory instead.
   • As a result, the files are actually placed under install_path/package_name.
3. Then, symin recursively creates symbolic links under export_root/usr pointing to all files that are installed under install_path/package_name.
   • As a result, the installed files are visible in the exported paths to the $PATH and $LD_LIBRARY_PATH environment variables without actually being installed there.
   • The files find each other under export_root/usr as they expect.
   • The packages are keeped separated in different directories.

symin uninstalls a package package_name by removing the files in the export_root/usr that point to the install_path/package_name, and then removing the install_path/package_name itself.