simple mail search tool for mew-prog-grep

mewgrep.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# by Akihiro Uchida, CC0 dedicated to the public domain
# see http://creativecommons.org/publicdomain/zero/1.0/
import sys, re
import email, email.header
import os.path
import argparse
from locale import getpreferredencoding

DEFAULT_ENCODING = 'cp932'
def contains_in_header(regex, header):
    parts = email.header.decode_header(header)
    try:
        header = u"".join([s.decode(e or DEFAULT_ENCODING) for s, e in parts])
    except UnicodeDecodeError:
        print >> sys.stderr, 'Error: cannot decode header.'
        header = u"".join([s.decode(e or DEFAULT_ENCODING, 'ignore')
                           for s, e in parts])
    if regex.search(header):
        return True
    return False

def contains_in_body(regex, part):
    payload = part.get_payload(decode=True)
    try:
        encoding = part.get_content_charset(DEFAULT_ENCODING)
        body = payload.decode(encoding)
    except UnicodeDecodeError:
        print >> sys.stderr, 'Error: cannot decode body.'
        body = payload.decode(encoding, 'ignore')
    for line in body.splitlines():
        if regex.search(line):
            return True
    return False

def contains(regex, msg):
    for header in msg.values():
        if contains_in_header(regex, header):
            return True
    if msg.is_multipart():
        for part in msg.get_payload():
            content_type = part.get_content_type()
            if content_type == 'text/plain':
                if contains_in_body(regex, part):
                    return True
            elif content_type == 'message/rfc822':
                if contains(regex, part):
                    return True
    else:
        if contains_in_body(regex, msg):
            return True
    return False

if __name__ == '__main__':
    desc = 'simple mail search tool for mew-prog-grep'
    parser = argparse.ArgumentParser(description=desc)
    parser.add_argument('-i', '--input-encoding', metavar='encoding',
                        dest='enc', type=str, default=getpreferredencoding())
    parser.add_argument('pattern', metavar='pattern', type=str)
    parser.add_argument('files', metavar='file', nargs='*')
    args = parser.parse_args()
    regex = re.compile(args.pattern.decode(args.enc))
    for fn in args.files:
        if not os.path.isfile(fn):
            print >> sys.stderr, 'Error: {} is not a regular file.'.format(fn)
            continue
        with open(fn, 'r') as f:
            msg = email.message_from_file(f)
        if contains(regex, msg):
            print fn

sample-mew.el

(setq mew-prog-grep "mewgrep.py")
(setq mew-prog-grep-opts '())
;(setq mew-prog-grep-opts '("-i" "euc_jp"))