| #!/usr/bin/env python2 |
| # Copyright 2019 The Chromium OS Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| import sys |
| |
| def chargen(modulo, max_chars): |
| """Generate a stream of characters on the console. |
| |
| The stream is an ever incrementing pattern of characters from the |
| following set: 0..9A..Za..z. |
| |
| Args: |
| modulo: an int, restart the pattern every modulo characters, if |
| modulo is non zero |
| max_chars: an int, stop printing after this number of characters if non |
| zero, if zero - print indefinitely |
| """ |
| |
| base = '0' |
| c = base |
| counter = 0 |
| while True: |
| sys.stdout.write(c) |
| counter = counter + 1 |
| |
| if (max_chars != 0) and (counter == max_chars): |
| sys.stdout.write('\n') |
| return |
| |
| if modulo and ((counter % modulo) == 0): |
| c = base |
| continue |
| |
| if c == 'z': |
| c = base |
| elif c == 'Z': |
| c = 'a' |
| elif c == '9': |
| c = 'A' |
| else: |
| c = '%c' % (ord(c) + 1) |
| |
| |
| def main(args): |
| '''Process command line arguments and invoke chargen if args are valid''' |
| |
| modulo = 0 |
| max_chars = 0 |
| |
| try: |
| if len(args) > 0: |
| modulo = int(args[0]) |
| if len(args) > 1: |
| max_chars = int(args[1]) |
| except ValueError: |
| sys.stderr.write('usage %s:' |
| "['seq_length' ['max_chars']]\n") |
| sys.exit(1) |
| |
| try: |
| chargen(modulo, max_chars) |
| except KeyboardInterrupt: |
| print |
| |
| if __name__ == '__main__': |
| main(sys.argv[1:]) |
| sys.exit(0) |