Transformations entry¶

For examples of transformation uses, see:

• Handle compressed directories
• Handle secrets

Notes:

• Any transformation with a key starting with an underscore (_) won't be shown in output. This can be useful when working with sensitive data containing passwords, for example.
• Make sure to quote your transformations to avoid bad surprises
• Transformations are executed using the default shell ($SHELL)
• To use shell variables in your transformations you need to escape the curly brackets (${HOME} becomes ${{HOME}})

There are two types of transformations available:

• Read transformations: used to transform dotfiles before they are installed (config key trans_read)

  • Used for commands install and compare
  • They have two mandatory arguments:
    • {0} will be replaced with the dotfile to process
    • {1} will be replaced with a temporary file to store the result of the transformation
  • This Happens before the dotfile is templated (see templating)

• Write transformations: used to transform files before updating a dotfile (config key trans_write)

  • Used for command update and import
  • They have two mandatory arguments:
    • {0} will be replaced with the file path to update the dotfile with
    • {1} will be replaced with a temporary file to store the result of the transformation

A typical use-case for transformations is when dotfiles need to be stored encrypted or compressed. For more, see the howto.

Note that transformations cannot be used if the dotfile is to be linked (when link: absolute|relative|link_children).

Transformations also support additional positional arguments that must start from 2 (since {0} and {1} are added automatically). The transformations themselves as well as their arguments can also be templated.

For example:

trans_read:
  targ: echo "$(basename {0}); {{@@ _dotfile_key @@}}; {2}; {3}" > {1}
dotfiles:
  f_abc:
    dst: /tmp/abc
    src: abc
    trans_read: targ "{{@@ profile @@}}" lastarg
profiles:
  p1:
    dotfiles:
    - f_abc

will result in abc; f_abc; p1; lastarg.

trans_read entry¶

The trans_read entry (optional) contains a transformations mapping (See transformations).

trans_read:
   <trans-key>: <command-to-execute>

trans_write entry¶

The trans_write entry (optional) contains a write transformations mapping (See transformations).

trans_write:
   <trans-key>: <command-to-execute>

Dynamic transformations¶

As for dynamic actions, transformations support the use of variables (variables and dynvariables and template variables).

A very dumb example:

trans_read:
  r_echo_abs_src: echo "{0}: {{@@ _dotfile_abs_src @@}}" > {1}
  r_echo_var: echo "{0}: {{@@ r_var @@}}" > {1}
trans_write:
  w_echo_key: echo "{0}: {{@@ _dotfile_key @@}}" > {1}
  w_echo_var: echo "{0}: {{@@ w_var @@}}" > {1}
variables:
  r_var: readvar
  w_var: writevar
dotfiles:
  f_abc:
    dst: ${tmpd}/abc
    src: abc
    trans_read: r_echo_abs_src
    trans_write: w_echo_key
  f_def:
    dst: ${tmpd}/def
    src: def
    trans_read: r_echo_var
    trans_write: w_echo_var