ConMan: Configuration-file Manager

ConMan is tool for managing dotfiles and other config files on multiple unix systems, each requiring largely the same set of files but with minor changes in each location. The system is built on the m4 macro processor which is widely installed and reasonably powerful.

Tutorial

Configuration/dot file templates should be placed in ConMan/configs/*.m4 (can be overridden by -t). In the simplest case this requires just a single modification. For example:

CONFIG_FILE(my bash rc, ~/.bashrc)

# bashrc continues as-per-normal below...

This defines the contents of ~/.bashrc for all machines. Nice and straight forward. Note: as this is still a 'normal' m4 script you must ensure that templates don't accidentally trigger any m4 functionality.

Obviously this isn't very useful as we want to make things only appear for certain machines. Say we have a config file we only want on machines in my university department, we can make the config file conditional like so:

CONFIG_FILE(ARCADE Settings, ~/.arcaderc, UNI)

# ...configuration file for some university software here...

The extra argument here (UNI) is an expression saying which computers this file should be present on. See the 'Defining Computers' section to see how you define these names.

Given that your dotfiles are also now in m4 you can use other macros to clean up your configs. Some macros are provided by ConMan to help make fine-grain conditional inclusion easier:

CONFIG_FILE(Example File, ~/.examplerc)

These lines appear on all computers (as usual).

ON_COMPUTER(LAPTOP)
        These lines only appear on my laptop's version of exaple RC.
        How lovely!
ELSE_COMPUTER()
        These lines only appear on other computers' versions.
END_COMPUTER()

IF_COMPUTER(LAPTOP|UNI_RESEARCH_DOMAIN,
        `only appears on laptop & uni on the research domain',
        `appears everywhere else')

Finally, it is also worth noting that you can have multiple files defined in one template. For example, your bashrc and bashprofile all in one template:

CONFIG_FILE(my bashrc, ~/.bashrc)

# Stuff from your bashrc goes here. Maybe you define/use some handy m4 macros?

CONFIG_FILE(my bashprofile, ~/.bashprofile)

# Stuff for the bash profile goes here (still the same file!). Maybe you can
# use some of those handy macros again here too?

Defining Computers

A list of all the computers which your config files might apply to should be defined in the 'global' configuration file ConMan/config.m4 (or alternatively the file specified by the -C argument) like so:

DEFINE_COMPUTER(LAPTOP)
DEFINE_COMPUTER(DESKTOP)
DEFINE_COMPUTER(UNI_TEACHING_DOMAIN)
DEFINE_COMPUTER(UNI_RESEARCH_DOMAIN)

It is also possible to group combinations of computers (and groups) under a common label. For example, you can add:

DEFINE_GROUP(PERSONAL, LAPTOP | DESKTOP)
DEFINE_GROUP(UNI,      UNI_RESEARCH_DOMAIN | UNI_TEACHING_DOMAIN)

Each computer also has a 'local' configuration file ConMan/local_config.m4 (or alternatively the file specified by the -c argument) which simply defines which computer this actually is:

SET_COMPUTER(LAPTOP)

Backups

When a config file is created from a template, a backup is made in ConMan/backups (or the directory set by -b). If the file being created doesn't match its backup then you'll be asked to confirm the overwrite. This is designed to protect against overwriting changes made to config files by other utilities.

You can force ConMan to overwrite files which don't match their backups using the -f option.

Quickly editing files

Using conman -e filename will attempt to open the M4 file which created the given file in your $EDITOR.

Health Warnings

There are a few thins you should be aware of when using ConMan. Hopefully these should be resolved over time but for now...

1. It is worth mentioning a second time: your templates are just regular m4 and so must be careful to avoid any keywords etc. A list of extra keywords to avoid due to ConMan can be found by reading its source (sorry...).
2. Your m4 templates actually get parsed 1+n times (where n is the number of config files defined within it). This is due to the current bodge being used to get multiple files (and their file names) out of an m4 file. This may change to use a different bodge at some time in the future which solves this...
3. Be very careful using m4's divert command in your m4 scripts... Hopefully this will be cleaned up in the future...

Plugins

ConMan can be extended with plugins giving it extra functionality. These are documented below.

Git

The GIT_REPO(local_dir, repo_url) macro requests the git repo stored in local_dir is pulled from repo_url. For example, here it is fetching various VIM plugins:

CONFIG_FILE(my vim configs, ~/.vimrc)

" stuff for my .vimrc goes here as usual

GIT_REPO(~/.vim/bundle/pathogen, git://github.com/tpope/vim-pathogen.git)
GIT_REPO(~/.vim/bundle/fugitive, git://github.com/tpope/vim-fugitive.git)
GIT_REPO(~/.vim/bundle/ctrlp,    git://github.com/kien/ctrlp.vim.git)

The plugin can be disabled using the -g flag.

Binary File Installer

The INSTALL_BINARY(src, dst) macro copies a binary file (make sure it doesn't end in .m4 to prevent conman processing it as a template) at the location "src" (relative to the m4 file's directory) into dst. For example, this installs a nice font for vim:

CONFIG_FILE(my vim configs, ~/.vimrc)

" stuff for my .vimrc goes here as usual

INSTALL_BINARY(Monaco_Linux.ttf,~/.fonts/)

The plugin can be disabled using the -B flag.

For Plugin Developers

ConMan searches for plugins in ConMan/plugins (but this can be overridden by -p). There are two types of plugin:

• Files ending in .m4 will be included after ConMan's header and before the target m4 file. What you do here is up to you. Have fun.
• Executable (bash) files ending in .sh will be sourced by ConMan. The rest of the documentation in this section describes the facilities available to the plugin writer.

Defining Macros

The easiest way to define an macro is to define a suitable bash function and use add_m4_command to make it available to m4 like so:

function touch_file() {
        touch "$1"
}

add_m4_command "TOUCH_FILE" "touch_file"

This defines the m4 macro TOUCH_FILE which essentially wraps the bash function touch_file passing on all arguments. For example if you place the following in a template:

TOUCH_FILE(/tmp/some_file)dnl

The file /tmp/some_file will be touched.

Warning: Arguments given to the m4 wrapper will be (double) quoted but not escaped so watch out!

The environment variable $M4_FILE is set with the full path of the m4 file which called the the macro.

Defining Macros (Advanced)

You can append m4 commands into the file defined by $M4_INCLUDE which is included by m4 after the ConMan header and before the target m4 file.

Adding ConMan Arguments

You can add command-line arguments to ConMan.

Calling Functions

You can define an argument which, when given, executes a function using add_argument. This takes an argument to match, a bash expression to eval if found and a documentation string, e.g.:

add_argument -t "echo testing $1;shift" "Print 'testing' and the argument on stdout."

Remember that arguments can be accessed via $1 etc. remember to shift any that you use.

Setting Variabls

If you just want to add an argument that overrides a bash variable with the argument given, you can use add_argument_var which takes an argument to match, a variable name to override and a help string. For example:

MY_VAR="initial value"
add_argument_var -v "MY_VAR" "Override MY_VAR."

If called without an argument, $MY_VAR will remain 'initial value' but if called with -v something then $MY_VAR will be set to 'something'.