update_usage.py

#!/usr/bin/env python3

import re, sys, os
import subprocess
from subprocess import Popen, PIPE

if __name__ == "__main__":
    with open('docs/usage.md') as f:
      content = f.read()

    command = subprocess.run(["cargo", "build"])
    if command.returncode != 0:
        print('Cargo build exited with code ' + str(command.returncode))
        exit(command.returncode)

    build_dir = os.path.dirname(os.path.realpath(__file__))
    target_dir = os.path.join(build_dir, "target", "debug")

    for p in os.listdir(target_dir):
        if p.startswith("casr-") \
                and os.path.isfile(target := os.path.join(target_dir, p)) \
                and os.access(target, os.X_OK):
            command = Popen([target, "-h"], stdout=PIPE, stderr=PIPE)
            out, _ = command.communicate()
            output = str(out, 'utf-8', errors='ignore')
            splitted = output.split('\n\n')
            number_of_sections = len(splitted)
            if number_of_sections != 4 and number_of_sections != 3:
                print('Bad format in help message: ' + p)
                continue
            for i in range(1, number_of_sections):
                splitted[i] = '\n'.join(['    ' + line for line in splitted[i].split('\n') if line])
            new_message = '\n\n'.join(splitted) + '\n\n'
            content = re.sub(f'## {p}\n\n' + '(.|\n)*?\n\n(\s+.*\n\n?)+', \
                             f'## {p}\n\n' + new_message, \
                             content)

    with open('docs/usage.md', 'w') as f:
      f.write(content)