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#!/usr/bin/env python
# Copyright 1999-2007 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id$
import os, re, sys
egrep_compat_map = {
"[:alnum:]" : r'\w',
"[:digit:]" : r'\d',
"[:space:]" : r'\s',
}
here_doc_re = re.compile(r'.*\s<<[-]?(\w+)$')
func_start_re = re.compile(r'^[-\w]+\s*\(\)\s*$')
func_end_re = re.compile(r'^\}$')
var_assign_re = re.compile(r'(^|^declare\s+-\S+\s+|^export\s+)([^=\s]+)=("|\')?.*$')
close_quote_re = re.compile(r'(\\"|"|\')\s*$')
def compile_egrep_pattern(s):
for k, v in egrep_compat_map.iteritems():
s = s.replace(k, v)
return re.compile(s)
def have_end_quote(quote, line):
"""
Check if the line has an end quote (useful for handling multi-line
quotes). This handles escaped double quotes that may occur at the
end of a line. The posix spec does not allow escaping of single
quotes inside of single quotes, so that case is not handled.
"""
close_quote_match = close_quote_re.search(line)
return close_quote_match is not None and \
close_quote_match.group(1) == quote
def filter_bash_environment(pattern, file_in, file_out):
here_doc_delim = None
in_func = None
multi_line_quote = None
multi_line_quote_filter = None
for line in file_in:
if multi_line_quote is not None:
if not multi_line_quote_filter:
file_out.write(line)
if have_end_quote(multi_line_quote, line):
multi_line_quote = None
multi_line_quote_filter = None
continue
if here_doc_delim is None and in_func is None:
var_assign_match = var_assign_re.match(line)
if var_assign_match is not None:
quote = var_assign_match.group(3)
filter_this = pattern.match(var_assign_match.group(2)) \
is not None
if quote is not None and not have_end_quote(quote, line):
multi_line_quote = quote
multi_line_quote_filter = filter_this
if not filter_this:
file_out.write(line)
continue
if here_doc_delim is not None:
if here_doc_delim.match(line):
here_doc_delim = None
file_out.write(line)
continue
here_doc = here_doc_re.match(line)
if here_doc is not None:
here_doc_delim = re.compile("^%s$" % here_doc.group(1))
file_out.write(line)
continue
# Note: here-documents are handled before fuctions since otherwise
# it would be possible for the content of a here-document to be
# mistaken as the end of a function.
if in_func:
if func_end_re.match(line) is not None:
in_func = None
file_out.write(line)
continue
in_func = func_start_re.match(line)
if in_func is not None:
file_out.write(line)
continue
# This line is not recognized as part of a variable assignment,
# function definition, or here document, so just allow it to
# pass through.
file_out.write(line)
if __name__ == "__main__":
description = "Filter out variable assignments for varable " + \
"names matching a given PATTERN " + \
"while leaving bash function definitions and here-documents " + \
"intact. The PATTERN should use python regular expression syntax" + \
" but [:digit:], [:space:] and " + \
"[:alnum:] character classes will be automatically translated " + \
"for compatibility with egrep syntax."
usage = "usage: %s PATTERN" % os.path.basename(sys.argv[0])
from optparse import OptionParser
parser = OptionParser(description=description, usage=usage)
options, args = parser.parse_args(sys.argv[1:])
if len(args) != 1:
parser.error("Missing required PATTERN argument.")
file_in = sys.stdin
file_out = sys.stdout
filter_bash_environment(
compile_egrep_pattern(args[0]), file_in, file_out)
file_out.flush()
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