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+"""
+A lexical analyzer class for simple shell-like syntaxes.
+
+Tweaked for the specific needs of parsing poezio input.
+
+"""
+
+# 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
+import re
+import sys
+from collections import deque
+
+from io import StringIO
+
+__all__ = ["shlex", "split", "quote"]
+
+class shlex:
+ """
+ A custom version of the shlex in the stdlib to yield more information
+ """
+ def __init__(self, instream=None, infile=None, posix=True):
+ if isinstance(instream, str):
+ 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
+ self.eof = ''
+ self.commenters = ''
+ self.wordchars = ('abcdfeghijklmnopqrstuvwxyz'
+ 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_')
+ if self.posix:
+ self.wordchars += ('ßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿ'
+ 'ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞ')
+ self.whitespace = ' \t\r\n'
+ self.whitespace_split = True
+ 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, str):
+ 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.
+ start, end, raw = self.read_token()
+ # Handle inclusions
+ # Maybe we got EOF instead?
+ while raw == self.eof:
+ if not self.filestack:
+ return self.eof
+ else:
+ self.pop_source()
+ start, end, 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 start, end, raw
+
+ def read_token(self):
+ quoted = False
+ escapedstate = ' '
+ token_start = 0
+ token_end = -1
+ 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
+ token_end = self.instream.tell()
+ break
+ elif self.state == ' ':
+ if not nextchar:
+ self.state = None # end of file
+ token_end = self.instream.tell()
+ 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):
+ token_end = self.instream.tell() - 1
+ 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:
+ token_start = self.instream.tell() - 1
+ escapedstate = 'a'
+ self.state = nextchar
+ elif nextchar in self.wordchars:
+ token_start = self.instream.tell() - 1
+ self.token = nextchar
+ self.state = 'a'
+ elif nextchar in self.quotes:
+ token_start = self.instream.tell() - 1
+ self.state = nextchar
+ elif self.whitespace_split:
+ token_start = self.instream.tell() - 1
+ self.token = nextchar
+ self.state = 'a'
+ else:
+ token_start = self.instream.tell() - 1
+ self.token = nextchar
+ if self.token or (self.posix and quoted):
+ token_end = self.instream.tell() - 1
+ 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?
+ token_end = self.instream.tell()
+ break
+ if nextchar == self.state:
+ if not self.posix:
+ self.token = self.token + nextchar
+ self.state = ' '
+ token_end = self.instream.tell()
+ 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?
+ token_end = self.instream.tell()
+ break
+ # 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
+ token_end = self.instream.tell()
+ 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):
+ token_end = self.instream.tell() - 1
+ 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:
+ token_end = self.instream.tell()
+ 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 (token_start, token_end, 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, str) 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 and token[0] == 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)
+
+
+_find_unsafe = re.compile(r'[^\w@%+=:,./-]', re.ASCII).search
+
+def quote(s):
+ """Return a shell-escaped version of the string *s*."""
+ if not s:
+ return "''"
+ if _find_unsafe(s) is None:
+ return s
+
+ # use single quotes, and put single quotes into double quotes
+ # the string $'b is then quoted as '$'"'"'b'
+ return "'" + s.replace("'", "'\"'\"'") + "'"
+
+
+if __name__ == '__main__':
+ lexer = shlex(instream=sys.argv[1])
+ while 1:
+ tt = lexer.get_token()
+ if tt:
+ print("Token: " + repr(tt))
+ else:
+ break
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