#! /usr/bin/env python # Print From and Subject of messages in $MAIL.# Extension to multiple mailboxes and other bells & whistles are left# as exercises for the reader. import sys, os # Open mailbox file.  Exits with exception when this fails. try:    mailbox = os.environ['MAIL']except (AttributeError, KeyError):    sys.stderr.write('No environment variable $MAIL\n')    sys.exit(2) try:    mail = open(mailbox)except IOError:    sys.exit('Cannot open mailbox file: ' + mailbox) while 1:    line = mail.readline()    if not line:        break # EOF    if line.startswith('From '):        # Start of message found        print line[:-1],        while 1:            line = mail.readline()            if not line or line == '\n':                break            if line.startswith('Subject: '):                print repr(line[9:-1]),        print