Mailing List Archive

(YAS == Yet Another Solution)

This solution introduces file-like objects which do the Right Thing(TM) at
EOF: raise EOFError (instead of returning an empty string)

----------------- cut here ------------------
class File:
'''\
File-like objects which throw EOFError on End-of-File.

Initialize with a file-like object.
'''
def __init__(self, file):
self.__file=file

def __getattr__(self, name):
if name[:4]!='read':
return getattr(self.__file, name)
return _Wrap(getattr(self.__file, name))

class _Wrap:
def __init__(self, function):
self.function=function

def __call__(self, *args, **kw):
ret=apply(self.function, args, kw)
if ret=='': raise EOFError, 'no more data in file'
return ret

def open(file, mode='r'):
'''\
return a file like object open to /file/ with mode /mode/,
which throws an EOFError on EOF
'''
import __builtin__
return File(__builtin__.open(file, mode))

def _test():
import sys
file=open('/etc/passwd')
try:
while 1:
sys.stdout.write(file.readline())
except EOFError: pass

if __name__=='__main__':
_test()
---------------------------- cut here ---------------------------

--
Moshe Zadka <mzadka@geocities.com>.
#!/usr/bin/tail -1
Just another tail hacker.