strftime

#!/usr/bin/env python
'''Convert seconds since epoch to human readable time format.
   Useful in cases where logs dump time information in epoch.

    $ echo 1255099899 | strftime
    10/09/2009 07:51
    $
'''

from time import strftime, localtime
import re

def main(argv=None):
    import sys
    from optparse import OptionParser

    argv = argv or sys.argv

    default_format = "%m/%d/%Y %H:%M"
    parser = OptionParser("%prog [options] [FILENAME]")
    parser.add_option("--format", dest="format",
        help="time format [%s]" % default_format, default=default_format)
    parser.add_option("--doc", help="show strftime documentation",
        dest="doc", action="store_true", default=0)
    parser.add_option("--quote", help="quote result (e.g. '10/2/2009')",
        dest="quote", default="")

    opts, args = parser.parse_args(argv[1:])
    if len(args) not in (0, 1):
        parser.error("wrong number of arguments") # Will exit

    if opts.doc:
        import webbrowser
        url = "http://docs.python.org/library/time.html#time.strftime"
        webbrowser.open(url)
        raise SystemExit

    infile = args[0] if args else "-"
    if infile == "-":
        info = sys.stdin
    else:
        try:
            info = open(infile)
        except IOError, e:
            raise SystemExit("error: can't open %s - %s" % (infile, e))

    def callback(match):
        t = localtime(float(match.group()))
        human = strftime(opts.format, t)
        if opts.quote:
            human = human.replace(opts.quote, r"\\%s" % opts.quote)
            human = opts.quote + human + opts.quote

        return human

    # We assume 1XXXXXXXXX (2001 +) dates, so we won't convert *everything*
    print re.sub("1\d{9}(\.\d+)?", callback, info.read())


if __name__ == "__main__":
    main()