| # -*- 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 |