#!/usr/bin/env python
# Copyright 2019 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# This utility concatenates several files into one. On Unix-like systems
# it is equivalent to:
# cat file1 file2 file3 ...files... > target
#
# The reason for writing a separate utility is that 'cat' is not available
# on all supported build platforms, but Python is, and hence this provides
# us with an easy and uniform way of doing this on all platforms.
# for py2/py3 compatibility
from __future__ import print_function
import optparse
import sys
def Concatenate(filenames):
"""Concatenate files.
Args:
files: Array of file names.
The last name is the target; all earlier ones are sources.
Returns:
True, if the operation was successful.
"""
if len(filenames) < 2:
print("An error occurred generating %s:\nNothing to do." % filenames[-1])
return False
try:
with open(filenames[-1], "wb") as target:
for filename in filenames[:-1]:
with open(filename, "rb") as current:
target.write(current.read())
return True
except IOError as e:
print("An error occurred when writing %s:\n%s" % (filenames[-1], e))
return False
def main():
parser = optparse.OptionParser()
parser.set_usage("""Concatenate several files into one.
Equivalent to: cat file1 ... > target.""")
(_options, args) = parser.parse_args()
sys.exit(0 if Concatenate(args) else 1)
if __name__ == "__main__":
main()