When possible, it is best to use the same files across all systems. However, there are occasions when you need different files in some places. Below are features and strategies for dealing with those occasions.
It can be useful to have an automated way of choosing an alternate version of a file for a different operating system, host, or user. yadm implements a feature which will automatically create a symbolic link to the appropriate version of a file, as long as you follow a specific naming convention. yadm can detect files with names ending in:
|Default file linked|
|Matching Class & OS|
|Matching Class, OS & Hostname|
|Matching Class, OS, Hostname, & User|
|Matching OS & Hostname|
|Matching OS, Hostname, & User|
If there are any files managed by yadm’s repository, or listed in
$HOME/.yadm/encrypt, which match this naming convention, symbolic links will be created for the most appropriate version. This may best be demonstrated by example. Assume the following files are managed by yadm’s repository:
$HOME/path/example.txt## $HOME/path/example.txt##Work $HOME/path/example.txt##Darwin $HOME/path/example.txt##Darwin.host1 $HOME/path/example.txt##Darwin.host2 $HOME/path/example.txt##Linux $HOME/path/example.txt##Linux.host1 $HOME/path/example.txt##Linux.host2
If running on a Macbook named
host2, yadm will create a symbolic link which looks like this:
However, on another Macbook named
host3, yadm will create a symbolic link which looks like this:
Since the host name doesn’t match any of the managed files, the more generic version is chosen.
If running on a Linux server named
host4, the link will be:
If running on a Solaris server, the link use the default
If running on a system, with
CLASS set to “Work” (see below), the link will be:
## version exists and no files match the current CLASS/OS/HOSTNAME/USER, then no link will be created.
|CLASS must be manually set using |
|OS is determined by running |
|HOSTNAME by running |
|USER by running |
yadm will automatically create these links by default. This can be disabled using the
yadm.auto-alt configuration. Even if disabled, links can be manually created by running yadm alt.
It is possible to use
% as a “wildcard” in place of
USER. For example, The following file could be linked for any host when the user is “harvey”.
Class and Overrides
Class is a special value which is stored locally on each host (inside the local repository). To use alternate symlinks using
CLASS, you must set the value of class using the configuration
local.class. This is set like any other yadm configuration—with the
yadm config command. The following sets the
CLASS to be “Work”.
yadm config local.class Work
Similarly, the values of
USER can be manually overridden using the configuration options
Strategies for alternate files on different systems
Where possible, you should try to use the same file on every system. Here are a few examples:
let OS=substitute(system('uname -s'),"\n","","") if (OS == "Darwin") " do something that only makes sense on a Mac endif
# use reattach-to-user-namespace as the default command on OSX if-shell "test -f /usr/local/bin/reattach-to-user-namespace" 'set -g default-command "reattach-to-user-namespace -l bash"'
system_type=$(uname -s) if [ "$system_type" = "Darwin" ]; then eval $(gdircolors $HOME/.dir_colors) else eval $(dircolors -b $HOME/.dir_colors) fi
However, sometimes the type of file you are using doesn’t allow for this type of logic. If a configuration can do an “include”, you can include a specific alternate version using yadm. Consider these three files:
[log] decorate = short abbrevCommit = true [include] path = .gitconfig.local
[user] name = Tim Byrne email = firstname.lastname@example.org
[user] name = Dr. Tim Byrne email = email@example.com
Configuring Git this way includes
.gitconfig.local in the standard
.gitconfig. yadm will automatically link the correct version based on the operating system. The bulk of your configurations can go in a single file, and you just put the exceptions in OS-specific files.