Yet Another Line Ending Conversion Program

This is what I've been using.. it's really simple, and should convert Win32, Mac, or Unix line endings to whatever your native line ending is. A possible future optimization would be to use temp files instead, but they're annoying.

#!/usr/bin/env python
import sys, os, shutil
from cStringIO import StringIO

def tonative(fname):
    buff = StringIO()
    infile = file(fname, 'rU')
    infile.readline()
    infile.seek(0)
    if infile.newlines == os.linesep:
        return
    for line in infile:
        buff.write(line.strip() + os.linesep)
    infile.close()
    outfile = file(fname, 'wb')
    buff.seek(0)
    shutil.copyfileobj(buff, outfile)
    outfile.close()

if __name__ == '__main__':
    for fname in sys.argv[1:]:
        tonative(fname)