Staging
v0.8.1
v0.8.1
swh:1:snp:635f4099902912592851108bcac178ff574f7c5f
Tip revision: 74f4bd53e03ded8408bcc2de67cf0f5a4ac5b1a1 authored by Barry Warsaw on 23 February 2012, 15:59:38 UTC
Bump some more copyright years (as per PEP 101), since this is the first
Bump some more copyright years (as per PEP 101), since this is the first
Tip revision: 74f4bd5
shlex.py
# -*- coding: iso-8859-1 -*-
"""A lexical analyzer class for simple shell-like syntaxes."""
# Module and documentation by Eric S. Raymond, 21 Dec 1998
# Input stacking and error message cleanup added by ESR, March 2000
# push_source() and pop_source() made explicit by ESR, January 2001.
# Posix compliance, split(), string arguments, and
# iterator interface by Gustavo Niemeyer, April 2003.
import os.path
import sys
from collections import deque
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
__all__ = ["shlex", "split"]
class shlex:
"A lexical analyzer class for simple shell-like syntaxes."
def __init__(self, instream=None, infile=None, posix=False):
if isinstance(instream, basestring):
instream = StringIO(instream)
if instream is not None:
self.instream = instream
self.infile = infile
else:
self.instream = sys.stdin
self.infile = None
self.posix = posix
if posix:
self.eof = None
else:
self.eof = ''
self.commenters = '#'
self.wordchars = ('abcdfeghijklmnopqrstuvwxyz'
'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_')
if self.posix:
self.wordchars += ('ßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿ'
'ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞ')
self.whitespace = ' \t\r\n'
self.whitespace_split = False
self.quotes = '\'"'
self.escape = '\\'
self.escapedquotes = '"'
self.state = ' '
self.pushback = deque()
self.lineno = 1
self.debug = 0
self.token = ''
self.filestack = deque()
self.source = None
if self.debug:
print 'shlex: reading from %s, line %d' \
% (self.instream, self.lineno)
def push_token(self, tok):
"Push a token onto the stack popped by the get_token method"
if self.debug >= 1:
print "shlex: pushing token " + repr(tok)
self.pushback.appendleft(tok)
def push_source(self, newstream, newfile=None):
"Push an input source onto the lexer's input source stack."
if isinstance(newstream, basestring):
newstream = StringIO(newstream)
self.filestack.appendleft((self.infile, self.instream, self.lineno))
self.infile = newfile
self.instream = newstream
self.lineno = 1
if self.debug:
if newfile is not None:
print 'shlex: pushing to file %s' % (self.infile,)
else:
print 'shlex: pushing to stream %s' % (self.instream,)
def pop_source(self):
"Pop the input source stack."
self.instream.close()
(self.infile, self.instream, self.lineno) = self.filestack.popleft()
if self.debug:
print 'shlex: popping to %s, line %d' \
% (self.instream, self.lineno)
self.state = ' '
def get_token(self):
"Get a token from the input stream (or from stack if it's nonempty)"
if self.pushback:
tok = self.pushback.popleft()
if self.debug >= 1:
print "shlex: popping token " + repr(tok)
return tok
# No pushback. Get a token.
raw = self.read_token()
# Handle inclusions
if self.source is not None:
while raw == self.source:
spec = self.sourcehook(self.read_token())
if spec:
(newfile, newstream) = spec
self.push_source(newstream, newfile)
raw = self.get_token()
# Maybe we got EOF instead?
while raw == self.eof:
if not self.filestack:
return self.eof
else:
self.pop_source()
raw = self.get_token()
# Neither inclusion nor EOF
if self.debug >= 1:
if raw != self.eof:
print "shlex: token=" + repr(raw)
else:
print "shlex: token=EOF"
return raw
def read_token(self):
quoted = False
escapedstate = ' '
while True:
nextchar = self.instream.read(1)
if nextchar == '\n':
self.lineno = self.lineno + 1
if self.debug >= 3:
print "shlex: in state", repr(self.state), \
"I see character:", repr(nextchar)
if self.state is None:
self.token = '' # past end of file
break
elif self.state == ' ':
if not nextchar:
self.state = None # end of file
break
elif nextchar in self.whitespace:
if self.debug >= 2:
print "shlex: I see whitespace in whitespace state"
if self.token or (self.posix and quoted):
break # emit current token
else:
continue
elif nextchar in self.commenters:
self.instream.readline()
self.lineno = self.lineno + 1
elif self.posix and nextchar in self.escape:
escapedstate = 'a'
self.state = nextchar
elif nextchar in self.wordchars:
self.token = nextchar
self.state = 'a'
elif nextchar in self.quotes:
if not self.posix:
self.token = nextchar
self.state = nextchar
elif self.whitespace_split:
self.token = nextchar
self.state = 'a'
else:
self.token = nextchar
if self.token or (self.posix and quoted):
break # emit current token
else:
continue
elif self.state in self.quotes:
quoted = True
if not nextchar: # end of file
if self.debug >= 2:
print "shlex: I see EOF in quotes state"
# XXX what error should be raised here?
raise ValueError, "No closing quotation"
if nextchar == self.state:
if not self.posix:
self.token = self.token + nextchar
self.state = ' '
break
else:
self.state = 'a'
elif self.posix and nextchar in self.escape and \
self.state in self.escapedquotes:
escapedstate = self.state
self.state = nextchar
else:
self.token = self.token + nextchar
elif self.state in self.escape:
if not nextchar: # end of file
if self.debug >= 2:
print "shlex: I see EOF in escape state"
# XXX what error should be raised here?
raise ValueError, "No escaped character"
# In posix shells, only the quote itself or the escape
# character may be escaped within quotes.
if escapedstate in self.quotes and \
nextchar != self.state and nextchar != escapedstate:
self.token = self.token + self.state
self.token = self.token + nextchar
self.state = escapedstate
elif self.state == 'a':
if not nextchar:
self.state = None # end of file
break
elif nextchar in self.whitespace:
if self.debug >= 2:
print "shlex: I see whitespace in word state"
self.state = ' '
if self.token or (self.posix and quoted):
break # emit current token
else:
continue
elif nextchar in self.commenters:
self.instream.readline()
self.lineno = self.lineno + 1
if self.posix:
self.state = ' '
if self.token or (self.posix and quoted):
break # emit current token
else:
continue
elif self.posix and nextchar in self.quotes:
self.state = nextchar
elif self.posix and nextchar in self.escape:
escapedstate = 'a'
self.state = nextchar
elif nextchar in self.wordchars or nextchar in self.quotes \
or self.whitespace_split:
self.token = self.token + nextchar
else:
self.pushback.appendleft(nextchar)
if self.debug >= 2:
print "shlex: I see punctuation in word state"
self.state = ' '
if self.token:
break # emit current token
else:
continue
result = self.token
self.token = ''
if self.posix and not quoted and result == '':
result = None
if self.debug > 1:
if result:
print "shlex: raw token=" + repr(result)
else:
print "shlex: raw token=EOF"
return result
def sourcehook(self, newfile):
"Hook called on a filename to be sourced."
if newfile[0] == '"':
newfile = newfile[1:-1]
# This implements cpp-like semantics for relative-path inclusion.
if isinstance(self.infile, basestring) and not os.path.isabs(newfile):
newfile = os.path.join(os.path.dirname(self.infile), newfile)
return (newfile, open(newfile, "r"))
def error_leader(self, infile=None, lineno=None):
"Emit a C-compiler-like, Emacs-friendly error-message leader."
if infile is None:
infile = self.infile
if lineno is None:
lineno = self.lineno
return "\"%s\", line %d: " % (infile, lineno)
def __iter__(self):
return self
def next(self):
token = self.get_token()
if token == self.eof:
raise StopIteration
return token
def split(s, comments=False, posix=True):
lex = shlex(s, posix=posix)
lex.whitespace_split = True
if not comments:
lex.commenters = ''
return list(lex)
if __name__ == '__main__':
if len(sys.argv) == 1:
lexer = shlex()
else:
file = sys.argv[1]
lexer = shlex(open(file), file)
while 1:
tt = lexer.get_token()
if tt:
print "Token: " + repr(tt)
else:
break