fix_fish_history.py

Running this fixer on a fish_history file converts it into valid YAML. This makes it easy to run any standard YAML parser on the output.

For example, this allows easily querying or sorting the YAML output.

No guarantee that fish can read the transformed YAML. (TODO) In this case, this script should log and remove the unparseable lines instead of attempting to fix them.

(TODO) Does not work with DOS \r\n newlines yet.

Fix some unparseable YAML lines and sort history

$ ./fix_fish_history.py file1 -o outputfile

Merge N fish history files

They need to be sorted so that fish will parse the output correctly.

$ ./fix_fish_history.py file1 file2 file3 -o outputfile

Usage

$ fix_fish_history --help
usage: fix_fish_history.py [-h] [--run-pytests] [--lint] [--verbose]
                           [--nosort] [--noparsefix] [--append]
                           [--out-fname OUT_FNAME]
                           fish_history_files [fish_history_files ...]

Fix or lint a fish_history file in various ways. Unparseable YAML and unsorted
history is detected and fixed. The output should be a valid YAML file.

positional arguments:
  fish_history_files    The fish_history file to fix

options:
  -h, --help            show this help message and exit
  --run-pytests         Just run the unit tests for this script if pytest is
                        installed.
  --lint                Just count the number of fixes, do not actually fix
                        them. This includes number of unsorted history entries
                        and number of YAML parse errors found.
  --verbose             Enable debug logging. This shows YAML parse error
                        details.
  --nosort              Do not sort lines in the history file
  --noparsefix          Do not try to fix parse errors
  --append, -a          Append to the output filename --out-fname do not
                        overwrite
  --out-fname OUT_FNAME, -o OUT_FNAME
                        Write fixed output to this file. Incompatible with
                        --lint

Related

This fixes some bad YAML output in the fish_history file, which prevented me from sorting multiple fish_history files easily to merge them into one.

See this issue related to some old fish yaml syntax errors: fish-shell/fish-shell#2759