Use scripts to perform actions
Understand how scripts work
chezmoi supports scripts, which are executed when you run chezmoi apply. The
scripts can either run every time you run chezmoi apply, only when their
contents have changed, or only if they have not been run before.
In verbose mode, the script's contents will be printed before executing it. In dry-run mode, the script is not executed.
Scripts are any file in the source directory with the prefix run_, and are
executed in alphabetical order. Scripts that should be run whenever their
contents change have the run_onchange_ prefix. Scripts that should only be run
if they have not been run before have the prefix run_once_.
Scripts break chezmoi's declarative approach, and as such should be used
sparingly. Any script should be idempotent, even run_onchange_ and run_once_
scripts.
Scripts are normally run while chezmoi updates your dotfiles. To configure
scripts to run before or after your dotfiles are updated use the before_ and
after_ attributes respectively, e.g.
run_once_before_install-password-manager.sh.
Scripts must be created manually in the source directory, typically by running
chezmoi cd and then creating a file with a run_ prefix. There is no need to
set the executable bit on the script.
Scripts with the suffix .tmpl are treated as templates, with the usual
template variables available. If, after executing the template, the result is
only whitespace or an empty string, then the script is not executed. This is
useful for disabling scripts.
When chezmoi executes a script, it first generates the script contents in a
file in a temporary directory with the executable bit set, and then executes
the contents with exec(3). Consequently, the script's contents must either
include a #! line or be an executable binary.
Set environment variables
You can set extra environment variables for your scripts in the scriptEnv
section of your config file. For example, to set the MY_VAR environment
variable to my_value, specify:
[scriptEnv]
MY_VAR = "my_value"
chezmoi sets a number of environment variables when running scripts, including
CHEZMOI=1 and common template data like CHEZMOI_OS and CHEZMOI_ARCH.
Note
By default, chezmoi diff will print the contents of scripts that would be
run by chezmoi apply. To exclude scripts from the output of chezmoi
diff, set diff.exclude in your configuration file, for example:
[diff]
exclude = ["scripts"]
Similarly, chezmoi status will print the names of the scripts that it
will execute with the status R. This can similarly disabled by setting
status.exclude to ["scripts"] in your configuration file.
Install packages with scripts
Change to the source directory and create a file called
run_onchange_install-packages.sh:
$ chezmoi cd
$ $EDITOR run_onchange_install-packages.sh
In this file create your package installation script, e.g.
#!/bin/sh
sudo apt install ripgrep
The next time you run chezmoi apply or chezmoi update this script will be
run. As it has the run_onchange_ prefix, it will not be run again unless its
contents change, for example if you add more packages to be installed.
This script can also be a template. For example, if you create
run_onchange_install-packages.sh.tmpl with the contents:
{{ if eq .chezmoi.os "linux" -}}
#!/bin/sh
sudo apt install ripgrep
{{ else if eq .chezmoi.os "darwin" -}}
#!/bin/sh
brew install ripgrep
{{ end -}}
This will install ripgrep on both Debian/Ubuntu Linux systems and macOS.
Run a script when the contents of another file changes
chezmoi's run_ scripts are run every time you run chezmoi apply, whereas
run_onchange_ scripts are run only when their contents have changed, after
executing them as templates. You can use this to cause a run_onchange_ script
to run when the contents of another file has changed by including a checksum of
the other file's contents in the script.
For example, if your dconf settings
are stored in dconf.ini in your source directory then you can make chezmoi
apply only load them when the contents of dconf.ini has changed by adding
the following script as run_onchange_dconf-load.sh.tmpl:
#!/bin/bash
# dconf.ini hash: {{ include "dconf.ini" | sha256sum }}
dconf load / < {{ joinPath .chezmoi.sourceDir "dconf.ini" | quote }}
As the SHA256 sum of dconf.ini is included in a comment in the script, the
contents of the script will change whenever the contents of dconf.ini are
changed, so chezmoi will re-run the script whenever the contents of dconf.ini
change.
In this example you should also add dconf.ini to .chezmoiignore so chezmoi
does not create dconf.ini in your home directory.
Clear the state of all run_onchange_ and run_once_ scripts
chezmoi stores whether and when run_onchange_ and run_once_ scripts have
been run in the scriptState bucket of its persistent state. To clear the state, run:
$ chezmoi state delete-bucket --bucket=scriptState