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# $Header: /var/local/cvsroot/4Suite/Ft/Lib/CommandLine/CommandLineUtil.py,v 1.12 2004/09/07 20:05:27 mbrown Exp $
"""
Utility functions used by command-line scripts
Copyright 2004 Fourthought, Inc. (USA).
Detailed license and copyright information: http://4suite.org/COPYRIGHT
Project home, documentation, distributions: http://4suite.org/
"""
import os, sys
from Ft.Lib import Uri, Wrap
__all__ = ['ArgumentError', 'GetoptError',
'wrap_text',
'SourceArgToUri', 'SourceArgToInputSource']
class ArgumentError(Exception):
pass
class GetoptError(Exception):
pass
def wrap_text(text, width):
"""
Split 'text' into multiple lines of no more than 'width' characters
each, and return the result as a list of strings.
This function differs from distutils.fancy_getopt.wrap_text() in
that the distutils version collapses blank lines; this one doesn't.
See also: Ft.Lib.Wrap()
"""
return Wrap(text, width).split('\n')
def SourceArgToUri(arg, resolver=Uri.BASIC_RESOLVER):
"""
Some command-line scripts take an argument that is supposed to be
either "-" (denoting standard input) or a URI reference that can be
resolved against the URI equivalent of the current working
directory. This function processes such an argument, given as a
string, and returns an appropriate URI.
Since users tend to expect local OS paths to work as URIs, this
function will accept and use an OS path argument if does appear to
point to an existing local file, even though this could interfere
with catalog-based resolution.
Raises a ValueError if arg is neither a local file nor a valid URI
reference nor "-".
The resolver object must support a normalize() method that
can resolve a URI reference against a base URI, returning a URI.
"""
if not isinstance(resolver, Uri.UriResolverBase):
msg = 'It appears there is a bug in this command-line' \
' script. A %s was passed as URI resolver to a function that' \
' requires an instance of Ft.Lib.Uri.UriResolverBase (or' \
' a subclass thereof).'
raise TypeError(msg % type(resolver))
if not isinstance(arg, str) and not isinstance(arg, unicode):
msg = 'It appears there is a bug in this command-line' \
' script. A %s was passed as an argument needing to be' \
' converted to a URI. A string must be provided instead.'
raise TypeError(msg % type(arg))
if arg == '-':
return Uri.OsPathToUri('unknown-STDIN', attemptAbsolute=True)
elif arg:
if os.path.isfile(arg):
return Uri.OsPathToUri(arg, attemptAbsolute=True)
elif not Uri.MatchesUriRefSyntax(arg):
raise ValueError("'%s' is not a valid URI reference." % arg)
elif Uri.IsAbsolute(arg):
return arg
base = Uri.OsPathToUri(os.getcwd(), attemptAbsolute=True)
if base[-1] != '/':
base += '/'
return resolver.normalize(arg, base)
def SourceArgToInputSource(arg, factory, *v_args, **kw_args):
"""
Some command-line scripts take an argument that is supposed to be
either "-" (denoting standard input) or a URI reference that can be
resolved against the URI equivalent of the current working
directory. This function processes such an argument, given as a
string, and returns an appropriate InputSource object.
Since users tend to expect local OS paths to work as URIs, this
function will accept and use an OS path argument if does appear to
point to an existing local file, even though this could interfere
with catalog-based resolution.
Raises a ValueError if arg is neither a local file nor a valid URI
reference nor "-". Raises a UriException if a stream for the
InputSource could not be opened (e.g., when the URI refers to a
directory or unreadable file).
Extra arguments given to this function are passed to the
InputSourceFactory method that creates the InputSource instance.
The factory must support the methods fromStream() and fromUri(),
as defined in Ft.Xml.InputSource.InputSourceFactory. The factory
must also provide a resolver object with a normalize() method that
can resolve a URI reference against a base URI, returning a URI.
"""
# It is important to require the caller to supply the factory,
# as we are in Ft.Lib, not Ft.Xml, so it is not safe to import
# Ft.Xml.InputSourceFactory. Also, we want to leave open the
# possibility that other factories can be used, perhaps to
# generate an InputSource that is not XML oriented or that is
# a subclass of Ft.Xml.InputSource.
if factory is None:
msg = 'It appears there is a bug in this command-line' \
' script. Python\'s "None" type was passed to a' \
' function that requires an instance of' \
' Ft.Xml.InputSource.InputSourceFactory.'
raise TypeError(msg)
sourceUri = SourceArgToUri(arg, factory.resolver)
if arg == '-':
v_args = (sys.stdin,) + v_args
kw_args['uri'] = sourceUri
isrc = factory.fromStream(*v_args, **kw_args)
else:
v_args = (sourceUri,) + v_args
isrc = factory.fromUri(*v_args, **kw_args)
return isrc
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