""" FileSplitter - Simple Python file split/concat module. What it does -==========- 1. Split a text/binary file into equal sized chunks and save them separately. 2. Concat existing chunks and recreate original file. Author: Anand Pillai Copyright : None, (Public Domain) """ import os, sys class FileSplitterException(Exception): def __init__(self, value): self.value = value def __str__(self): return str(self.value) def usage(): return """\nUsage: FileSplitter.py -i -n [option]\n Options:\n -s, --split Split file into chunks -j, --join Join chunks back to file. """ class FileSplitter: """ File splitter class """ def __init__(self): # cache filename self.__filename = '' # number of equal sized chunks self.__numchunks = 5 # Size of each chunk self.__chunksize = 0 # Optional postfix string for the chunk filename self.__postfix = '' # Program name self.__progname = "FileSplitter.py" # Action self.__action = 0 # split def parseOptions(self, args): import getopt try: optlist, arglist = getopt.getopt(args, 'sji:n:', ["split=", "join="]) except getopt.GetoptError, e: print e return None for option, value in optlist: if option.lower() in ('-i', ): self.__filename = value elif option.lower() in ('-n', ): self.__numchunks = int(value) elif option.lower() in ('-s', '--split'): self.__action = 0 # split elif option.lower() in ('-j', '--join'): self.__action = 1 # combine if not self.__filename: sys.exit("Error: filename not given") def do_work(self): if self.__action==0: self.split() elif self.__action==1: self.combine() else: return None def split(self): """ Split the file and save chunks to separate files """ print 'Splitting file', self.__filename print 'Number of chunks', self.__numchunks, '\n' try: f = open(self.__filename, 'rb') except (OSError, IOError), e: raise FileSplitterException, str(e) bname = (os.path.split(self.__filename))[1] # Get the file size fsize = os.path.getsize(self.__filename) # Get size of each chunk self.__chunksize = int(float(fsize)/float(self.__numchunks)) chunksz = self.__chunksize total_bytes = 0 for x in range(self.__numchunks): chunkfilename = bname + '-' + str(x+1) + self.__postfix # if reading the last section, calculate correct # chunk size. if x == self.__numchunks - 1: chunksz = fsize - total_bytes try: print 'Writing file',chunkfilename data = f.read(chunksz) total_bytes += len(data) chunkf = file(chunkfilename, 'wb') chunkf.write(data) chunkf.close() except (OSError, IOError), e: print e continue except EOFError, e: print e break print 'Done.' def sort_index(self, f1, f2): index1 = f1.rfind('-') index2 = f2.rfind('-') if index1 != -1 and index2 != -1: i1 = int(f1[index1:len(f1)]) i2 = int(f2[index2:len(f2)]) return i2 - i1 def combine(self): """ Combine existing chunks to recreate the file. The chunks must be present in the cwd. The new file will be written to cwd. """ import re print 'Creating file', self.__filename bname = (os.path.split(self.__filename))[1] bname2 = bname # bugfix: if file contains characters like +,.,[] # properly escape them, otherwise re will fail to match. for a, b in zip(['+', '.', '[', ']','$', '(', ')'], ['\+','\.','\[','\]','\$', '\(', '\)']): bname2 = bname2.replace(a, b) chunkre = re.compile(bname2 + '-' + '[0-9]+') chunkfiles = [] for f in os.listdir("."): print f if chunkre.match(f): chunkfiles.append(f) print 'Number of chunks', len(chunkfiles), '\n' chunkfiles.sort(self.sort_index) data='' for f in chunkfiles: try: print 'Appending chunk', os.path.join(".", f) data += open(f, 'rb').read() except (OSError, IOError, EOFError), e: print e continue try: f = open(bname, 'wb') f.write(data) f.close() except (OSError, IOError, EOFError), e: raise FileSplitterException, str(e) print 'Wrote file', bname def main(): import sys if len(sys.argv)<2: sys.exit(usage()) fsp = FileSplitter() fsp.parseOptions(sys.argv[1:]) fsp.do_work() if __name__=="__main__": main()