Adds header guards to multiple files

guard.py

import argparse
import glob
import logging
import os
import sys

logger = logging.getLogger(__name__)

def main(argv):
    """The main function for the script so it can be included if desired."""

    # Setup a nice little command prompt for running the script.
    parser = argparse.ArgumentParser(
        description="Console tool for applying header guards automatically."
    )

    parser.add_argument("directory",
                        default=os.getcwd(),
                        help="The root path for constructing the guard name.")
    parser.add_argument("-s", "--searchpos",
                        help="If specified, insert the guard after the " +
                             "specified search phrase.")
    parser.add_argument("-d", "--dryrun",
                        help="If specified, don't actually modify files.")
    parser.add_argument("-v", "--verbose",
                        help="Prints more information about the conversion.",
                        action="store_const",
                        dest="loglevel",
                        const=logging.INFO,
                        default=logging.WARNING)

    args = parser.parse_args()

    logging.basicConfig(level=args.loglevel)

    directory = os.path.abspath(args.directory)

    logger.info("Inserting guard after %s to files in directory %s",
                args.searchpos, directory)

    # Now get to work on adding the guards
    search_path = os.path.join(directory, "**", "*.h")
    for filename in glob.glob(search_path, recursive=True):
        with open(filename, "r") as read_fp:
            contents = read_fp.read()

        split_index = contents.find(args.searchpos) + 3 if args.searchpos is not None else 0
        before = contents[0:split_index]
        after = contents[split_index:]

        # If the file has a newline at the end, preserve it
        if after[-1] == "\n":
            after = after[:-1]
            tail = "\n"
        else:
            tail = ""

        # What is the guard we want to add? It depends on the path
        guard_name = filename[len(directory) + 1:].replace("\\", "_"). \
            replace("/", "_").replace(".", "_").upper()

        logger.info("%s -> insert at %d guard %s", filename, split_index, guard_name)

        guard = "\n#ifndef %s\n#define %s\n" % (guard_name, guard_name)

        if not args.dryrun:
            # Now construct the contents
            contents = before + guard + after + "\n#endif" + tail
            # And write to disk
            with open(filename, "w") as write_fp:
                write_fp.write(contents)
    

if __name__ == "__main__":
    sys.exit(main(sys.argv[1:]))