1 #!/usr/bin/env python 2 3 import os 4 import shutil 5 import sys 6 7 BUFFER_SIZE = 1024 8 9 def is_file_different(a, b): 10 if os.path.getsize(a) != os.path.getsize(b): 11 # If the file size is different, the content must be different. 12 return True 13 14 # Read the content of the files, and compare them. 15 result = False 16 17 fa = open(a, 'rb') 18 fb = open(b, 'rb') 19 20 while True: 21 buff_a = fa.read(BUFFER_SIZE) 22 buff_b = fb.read(BUFFER_SIZE) 23 24 if buff_a != buff_b: 25 # File is different in this block. 26 result = True 27 break 28 29 if len(buff_a) < BUFFER_SIZE: 30 # Finished 31 break 32 33 fa.close() 34 fb.close() 35 36 # File is the same. 37 return result 38 39 def copyfile(src, dest): 40 if not os.path.exists(src): 41 raise ValueError('Source file not found') 42 43 # Make parent directory (if necessary) 44 destdir = os.path.dirname(dest) 45 if not os.path.exists(destdir): 46 try: 47 os.makedirs(destdir) 48 except os.error, e: 49 raise ValueError('Unable to create directory ' + destdir) 50 elif not os.path.isdir(destdir): 51 raise ValueError(destdir + ' is not a directory') 52 53 if not os.path.exists(dest) or is_file_different(src, dest): 54 # If the destination file does not exist or the source file is 55 # different from the destination file, then we copy the file. 56 shutil.copyfile(src, dest) 57 58 def main(): 59 if len(sys.argv) < 3: 60 print >> sys.stderr, 'USAGE:', sys.argv[0], '<srcfile> <destfile>' 61 sys.exit(1) 62 63 srcfile = os.path.abspath(sys.argv[1]) 64 destfile = os.path.abspath(sys.argv[2]) 65 66 if srcfile == destfile: 67 print >> sys.stderr, 'WARNING: <srcfile> is equal to <destfile>' 68 else: 69 try: 70 copyfile(srcfile, destfile) 71 except ValueError, e: 72 print >> sys.stderr, 'ERROR: ', e 73 sys.exit(1) 74 75 if __name__ == '__main__': 76 main() 77
