Diff MySQL .cnf files

cnf-diff.py

import re
import sys
import json

var_pattern = re.compile(r'^(?!\[)(?P<var>[A-z_-]+)\s*(?:=\s*(?P<val>.*))?$')
scope_pattern = re.compile(r'^\s*\[(?P<scope>[A-z_-]+)\]\s*$')


def get_lines(file_path):
    with open(file_path, 'r') as f:
        yield from (l.strip() for l in f.readlines())


def normalize_var_name(var: str) -> str:
    return var.lower().replace('_', '-')


def get_vars(file_path):
    scope = ''
    for line in get_lines(file_path):
        if not line or line.startswith('#'):
            continue
        var_match = var_pattern.match(line)
        scope_match = scope_pattern.match(line)
        if var_match:
            var, val = var_match.groups()
            var = normalize_var_name(var)
            yield f'{scope}{var}', val
        elif scope_match:
            scope = f'{scope_match.groups()[0]}.'
        else:
            print(f'line did not match pattern: {line}')


def get_diff(first_vars, second_vars):
    first = set(first_vars)
    second = set(second_vars)
    return {k for k, v in (first ^ second)}, dict(first), dict(second)


def get_value(key, vars):
    try:
        return f'"{vars[key]}"'
    except KeyError:
        return 'missing'


if __name__ == '__main__':
    fst_file, snd_file = sys.argv[1:3]
    diff, first, second = get_diff(get_vars(fst_file), get_vars(snd_file))

    for var in diff:
        print(var)
        print(f'\t{get_value(var, first)} in {fst_file}')
        print(f'\t{get_value(var, second)} in {snd_file}')