#!/usr/bin/env python

"""

Utility for inspecting files in various ways.

This tool is like the collection of tools found in a unix environment but are

cross platform and stable and suitable for our needs in the test suite.

This can be used instead of tools like:

  [

  dd

  find

  head

  hexdump

  ls

  md5sum

  readlink

  sha1sum

  stat

  tail

  test

  readlink.py

  md5sum.py

"""

from __future__ import absolute_import

import glob

import hashlib

import optparse

import os

import re

import sys

def visit(opts, filenames, outfile):

    """Process filenames in the way specified in opts, writing output to

    outfile."""

    for f in sorted(filenames):

        isstdin = f == '-'

        if not isstdin and not os.path.lexists(f):

            outfile.write('%s: file not found\n' % f)

            continue

        quiet = opts.quiet and not opts.recurse or isstdin

        isdir = os.path.isdir(f)

        islink = os.path.islink(f)

        isfile = os.path.isfile(f) and not islink

        dirfiles = None

        content = None

        facts = []

        if isfile:

            if opts.type:

                facts.append('file')

            if opts.hexdump or opts.dump or opts.md5:

        elif islink:

            if opts.type:

                facts.append('link')

            content = os.readlink(f)

        elif isstdin:

            content = sys.stdin.read()

            if opts.size:

                facts.append('size=%s' % len(content))

        elif isdir:

            if opts.recurse or opts.type:

                dirfiles = glob.glob(f + '/*')

                facts.append('directory with %s files' % len(dirfiles))

        elif opts.type:

            facts.append('type unknown')

        if not isstdin:

            stat = os.lstat(f)

            if opts.size and not isdir:

                facts.append('size=%s' % stat.st_size)

            if opts.mode and not islink:

                facts.append('mode=%o' % (stat.st_mode & 0o777))

            if opts.links:

                facts.append('links=%s' % stat.st_nlink)

            if opts.newer:

                # mtime might be in whole seconds so newer file might be same

                if stat.st_mtime >= os.stat(opts.newer).st_mtime:

                    facts.append('newer than %s' % opts.newer)

                else:

                    facts.append('older than %s' % opts.newer)

        if opts.md5 and content is not None:

            h = hashlib.md5(content)

            facts.append('md5=%s' % h.hexdigest()[:opts.bytes])

        if opts.sha1 and content is not None:

            h = hashlib.sha1(content)

            facts.append('sha1=%s' % h.hexdigest()[:opts.bytes])

        if isstdin:

            outfile.write(', '.join(facts) + '\n')

        elif facts:

            outfile.write('%s: %s\n' % (f, ', '.join(facts)))

        elif not quiet:

            outfile.write('%s:\n' % f)

        if content is not None:

            chunk = content

            if not islink:

                if opts.lines:

                    if opts.lines >= 0:

                        chunk = ''.join(chunk.splitlines(True)[:opts.lines])

                    else:

                        chunk = ''.join(chunk.splitlines(True)[opts.lines:])

                if opts.bytes:

                    if opts.bytes >= 0:

                        chunk = chunk[:opts.bytes]

                    else:

                        chunk = chunk[opts.bytes:]

            if opts.hexdump:

                for i in range(0, len(chunk), 16):

                    s = chunk[i:i + 16]

                    outfile.write('%04x: %-47s |%s|\n' %

                                  (i, ' '.join('%02x' % ord(c) for c in s),

                                   re.sub('[^ -~]', '.', s)))

            if opts.dump:

                if not quiet:

                    outfile.write('>>>\n')

                outfile.write(chunk)

                if not quiet:

                    if chunk.endswith('\n'):

                        outfile.write('<<<\n')

                    else:

                        outfile.write('\n<<< no trailing newline\n')

        if opts.recurse and dirfiles:

            assert not isstdin

            visit(opts, dirfiles, outfile)

if __name__ == "__main__":

    parser = optparse.OptionParser("%prog [options] [filenames]")

    parser.add_option("-t", "--type", action="store_true",

                      help="show file type (file or directory)")

    parser.add_option("-m", "--mode", action="store_true",

                      help="show file mode")

    parser.add_option("-l", "--links", action="store_true",

                      help="show number of links")

    parser.add_option("-s", "--size", action="store_true",

                      help="show size of file")

    parser.add_option("-n", "--newer", action="store",

                      help="check if file is newer (or same)")

    parser.add_option("-r", "--recurse", action="store_true",

                      help="recurse into directories")

    parser.add_option("-S", "--sha1", action="store_true",

                      help="show sha1 hash of the content")

    parser.add_option("-M", "--md5", action="store_true",

                      help="show md5 hash of the content")

    parser.add_option("-D", "--dump", action="store_true",

                      help="dump file content")

    parser.add_option("-H", "--hexdump", action="store_true",

                      help="hexdump file content")

    parser.add_option("-B", "--bytes", type="int",

                      help="number of characters to dump")

    parser.add_option("-L", "--lines", type="int",

                      help="number of lines to dump")

    parser.add_option("-q", "--quiet", action="store_true",

                      help="no default output")

    (opts, filenames) = parser.parse_args(sys.argv[1:])

    if not filenames:

        filenames = ['-']

    visit(opts, filenames, sys.stdout)