swmod is a simple tool to manage custom compiled software (in your home directory or a central location). It handles software as "modules" - modules can be loaded, and new software packages can be installed into a module.

Basically, swmod sets environment variables like PATH and LD_LIBRARY_PATH and can automatically supply options like --prefix to configure scripts.

swmod is currently only works with bash, though it may in the future also support other sh-compatible shells. There are no plans to support tcsh or similar, so far.

Copy the shell script swmod.sh from bin into (e.g.)

$HOME/.local/bin

and add the following to your .bashrc (resp. .profile):

export PATH="$HOME/.local/bin:$PATH"
. swmod.sh init

You may, of course, use any other directory in your $PATH instead of $HOME/.local/bin.

Any directory structure of the form

MODULE_NAME/`swmod hostspec`/MODULE_VERSION

that looks like a binary software installation (there's a bin or lib directory or an swmod.deps file, etc.) can be used as an swmod software module.

The output of the swmod hostspec command (part of swmod) is a system specific string, e.g. "linux-ubuntu-12.04-x86_64", to support heterogeneous computing environments. You can override it with the environment variable $SWMOD_HOSTSPEC.

swmod looks for modules in all directories listed in the (colon-separated) path $SWMOD_MODPATH. $SWMOD_MODPATH defaults to $HOME/.local/sw/.

So a typical user-installed module might look like this:

$HOME/.local/sw/my-software/linux-ubuntu-12.04-x86_64/4.2

Of course, a module may comprise several individual software packages with the same installation prefix.

Just run

# swmod load mysoftware

or

# swmod load [email protected]

if you want to load a specific one. Otherwise swmod will try to guess which version is the current one. For numerical versions, it is legal to specify only a part of the version number:

# swmod load [email protected]

Again, swmod will try to do the right thing.

Important: In shell scripts (like .bashrc) you have to use

. swmod.sh load ...

instead of

swmod load ...

since the swmod alias that is set up by source swmod.sh init does not work in shell scripts.

swmod compatible software module can be created simply by manually installing (or copying) software packages into a prefix directory with a path of a certain structure (see above). However, swmod also provides several tools to assist with the installation of software packages into a module.

Fist, specify the installation target module and it's version, e.g.:

# swmod target [email protected]

This is the module (here, module "mysoftware", version "1.2.3"), into which you want to install your software. You can specify a new module, or add more software packages to an existing module.

By default, the module will be created under the path $HOME/.local/sw/. You can override the default installation base path with the environment variable $SWMOD_INST_BASE.

To make things more comfortable, you can use swmod target -l, e.g.

# swmod target -l [email protected]

as a shortcut for the frequently used combination

# swmod target [email protected]
# swmod load [email protected]

The software package(s) you want to install into your module ("mysoftware", in this example) may depend on other software to build and to run. You can permanently add dependencies on other modules to the target module using swmod add-deps:

# swmod add-deps [email protected] [email protected]

This way, the correct versions of your dependencies will be automatically loaded when you load your module:

# swmod load [email protected]

Use the -l option to immediately load the added dependencies, e.g.

# swmod add-deps -l [email protected] [email protected]

This comes in handy when adding dependencies to an already loaded module.

You may also add the special dependency !clflags. If added to a module, the include and library directories in the module will be added with -I and -L options to the environment variables SWMOD_CPPFLAGS and SWMOD_LDFLAGS. swmod configure and similar try to pass these through to the build system of packages to be configured or installed. Usually, this is not necessary as modern software uses mechanisms like ...-config or pkg-config ... to get the necessary compiler and linker options for their dependencies. Where such a mechanism is not provided, adding the special dependency !clflags can help.

Now build and install the desired software package(s) into the module. swmod has direct support for the following build systems:

• GNU Autotools (and compatible "configure" scripts)
• CMake
• Phyton setup.py

If the software package you want to install uses GNU Autoconf (and possibly Automake) or provides a compatible "configure" script, run swmod ./configure instead of ./configure. configure must support the usual options like --prefix for this to work. Then run make and make install as usual:

# swmod ./configure
# make && make install && echo OK

Afterwards, you should find a directory structure like this (depending on your system and the software package(s) you installed):

• $HOME/.local/sw/mysoftware/linux-ubuntu-14.04-x86_64/1.2.3/bin
• $HOME/.local/sw/mysoftware/linux-ubuntu-14.04-x86_64/1.2.3/lib
• ...

You can also use

# swmod path/to/project/dir/configure

for Autoconf/Automake out-of-tree builds (if supported by the project).

For CMake projects, use swmod cmake instead of cmake, then run make and make install as usual:

# cd my/build/dir
# swmod cmake path/to/project/dir
# make && make install && echo OK

To build and install Python projects based on "setup.py", use

# swmod setup.py

swmod will run python setup.py with the correct --prefix option (and also create the "site-packages" directory first, if necessary).

To download and install Python packages via pip, use

# swmod pip install ...

This is equivalent to

PYTHONUSERBASE="${SWMOD_INST_PREFIX}" pip install --user ...

If the software package you are installing uses SCons or another build system, you have to pass the installation target directory to the build system manually. swmod target exports an environment variable SWMOD_INST_PREFIX that may come in handy.

If your software module requires special initialization, environment variables, etc., a create shell script named swmodrc.sh inside $SWMOD_INST_PREFIX. swmod load will source this script - after loading the dependencies of the module, but before modifying environment variables (PATH, ...) for the module itself. Environment variables already modified by swmodrc.sh are skipped by swmod afterwards, instead of changing them in the usual fashion.

The variable SWMOD_INST_PREFIX is available from within swmodrc.sh. Also, the command swmod_load is available from within swmodrc.sh, to manually load other modules.

For example, if the software in question already provides a script like bin/env.sh, to set all paths and so on, just create a file swmodrc.sh containing

. "$SWMOD_PREFIX/bin/env.sh"

inside the $SWMOD_INST_PREFIX directory.