Staging
v0.5.1
v0.5.1
https://github.com/python/cpython
Tip revision: 74f4bd53e03ded8408bcc2de67cf0f5a4ac5b1a1 authored by Barry Warsaw on 23 February 2012, 15:59:38 UTC
Bump some more copyright years (as per PEP 101), since this is the first
Bump some more copyright years (as per PEP 101), since this is the first
Tip revision: 74f4bd5
rgrep.py
#! /usr/bin/env python
"""Reverse grep.
Usage: rgrep [-i] pattern file
"""
import sys
import re
import getopt
def main():
bufsize = 64*1024
reflags = 0
opts, args = getopt.getopt(sys.argv[1:], "i")
for o, a in opts:
if o == '-i':
reflags = reflags | re.IGNORECASE
if len(args) < 2:
usage("not enough arguments")
if len(args) > 2:
usage("exactly one file argument required")
pattern, filename = args
try:
prog = re.compile(pattern, reflags)
except re.error, msg:
usage("error in regular expression: %s" % str(msg))
try:
f = open(filename)
except IOError, msg:
usage("can't open %s: %s" % (repr(filename), str(msg)), 1)
f.seek(0, 2)
pos = f.tell()
leftover = None
while pos > 0:
size = min(pos, bufsize)
pos = pos - size
f.seek(pos)
buffer = f.read(size)
lines = buffer.split("\n")
del buffer
if leftover is None:
if not lines[-1]:
del lines[-1]
else:
lines[-1] = lines[-1] + leftover
if pos > 0:
leftover = lines[0]
del lines[0]
else:
leftover = None
lines.reverse()
for line in lines:
if prog.search(line):
print line
def usage(msg, code=2):
sys.stdout = sys.stderr
print msg
print __doc__
sys.exit(code)
if __name__ == '__main__':
main()