1#!/usr/bin/env python 2#===----------------------------------------------------------------------===## 3# 4# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5# See https://llvm.org/LICENSE.txt for license information. 6# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7# 8#===----------------------------------------------------------------------===## 9 10from argparse import ArgumentParser 11import sys 12 13def print_and_exit(msg): 14 sys.stderr.write(msg + '\n') 15 sys.exit(1) 16 17def main(): 18 parser = ArgumentParser( 19 description="Concatenate two files into a single file") 20 parser.add_argument( 21 '-o', '--output', dest='output', required=True, 22 help='The output file. stdout is used if not given', 23 type=str, action='store') 24 parser.add_argument( 25 'files', metavar='files', nargs='+', 26 help='The files to concatenate') 27 28 args = parser.parse_args() 29 30 if len(args.files) < 2: 31 print_and_exit('fewer than 2 inputs provided') 32 data = '' 33 for filename in args.files: 34 with open(filename, 'r') as f: 35 data += f.read() 36 if len(data) != 0 and data[-1] != '\n': 37 data += '\n' 38 assert len(data) > 0 and "cannot cat empty files" 39 with open(args.output, 'w') as f: 40 f.write(data) 41 42 43if __name__ == '__main__': 44 main() 45 sys.exit(0) 46