Concatenate a lot of files

fatcat.py

#!/usr/bin/env
# Copyright (c) 2020 Matt Borgerson
# 
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted.
# 
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
# OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

import argparse
import os
import os.path
import time

class SimpleProgress:
    def __init__(self, total=1):
        self._total = total
        self._count = 0
        self._last_reported_count = -1
    def __enter__(self):
        return self
    def __exit__(self, type, value, traceback):
        pass
    def update(self):
        self._count += 1
        if (self._count - self._last_reported_count) >= (self._total / 100.0):
            print('%d%% (%d of %d)...' % (int(self._count/self._total*100), self._count, self._total))
            self._last_reported_count = self._count

try:
    from tqdm import tqdm
except ImportError:
    tqdm = SimpleProgress

def main():
    args = argparse.ArgumentParser(description='Concatenate a lot of files')
    args.add_argument('outfile', help='path to output file')
    args.add_argument('indir', help='path to input dir (or cwd if blank)', default='.', nargs='?')
    args = args.parse_args()

    # Count files
    num_files = 0
    for root, dirs, files in os.walk(args.indir):
        num_files += len(files)

    outfile = os.open(args.outfile, os.O_WRONLY | os.O_CREAT | os.O_TRUNC)

    # Send 'em
    with tqdm(total=num_files) as t:
        for root, dirs, files in os.walk(args.indir):
            for f in files:
                path = os.path.join(root, f)
                infile = os.open(path, os.O_RDONLY)
                os.sendfile(outfile, infile, None, os.path.getsize(path))
                os.close(infile)
                t.update()

    os.close(outfile)

if __name__ == '__main__':
    main()