tests/readlink.py

doc: add the tool to check section marks in help documents

This patch adds "doc/check-seclevel.py" which checks below in help
documents:

  - whether unknown or unavailable section marks are used or not
  - whether appropriate section mark is used at sub-sectioning

It should be invoked in "doc" directory.

It checks all help documents of Mercurial (topics, commands,
extensions), if no file is specified by --file option.

With --file option, it checks contents of the specified file as help
document, for self testing purpose: -t/-c/-e/-C are used to specify
what kind of help document contents of the specified file is.

This checking is related to changeset 979b107eaea2.

#!/usr/bin/env python

import errno, os, sys

for f in sys.argv[1:]:
    try:
        print f, '->', os.readlink(f)
    except OSError, err:
        if err.errno != errno.EINVAL:
            raise
        print f, 'not a symlink'

sys.exit(0)