Implemented posix-mode parsing support in shlex.py, as dicussed in

mailing list, and in patch #722686.

2 files changed, 299 insertions, 24 deletions

diff --git a/Lib/shlex.py b/Lib/shlex.py
index 7ffa79c..863e404 100644
--- a/Lib/shlex.py
+++ b/Lib/shlex.py
@@ -1,28 +1,51 @@
+# -*- 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
 
-__all__ = ["shlex"]
+from types import StringTypes
+
+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):
+    def __init__(self, instream=None, infile=None, posix=0):
+        if type(instream) in StringTypes:
+            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 = 0
         self.quotes = '\'"'
+        self.escape = '\\'
+        self.escapedquotes = '"'
         self.state = ' '
         self.pushback = []
         self.lineno = 1
@@ -42,6 +65,8 @@ class shlex:
 
     def push_source(self, newstream, newfile=None):
         "Push an input source onto the lexer's input source stack."
+        if type(newstream) in StringTypes:
+            newstream = StringIO(newstream)
         self.filestack.insert(0, (self.infile, self.instream, self.lineno))
         self.infile = newfile
         self.instream = newstream
@@ -73,29 +98,31 @@ class shlex:
         # No pushback.  Get a token.
         raw = self.read_token()
         # Handle inclusions
-        while raw == self.source:
-            spec = self.sourcehook(self.read_token())
-            if spec:
-                (newfile, newstream) = spec
-                self.push_source(newstream, newfile)
-            raw = self.get_token()
+        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 == "":
+        while raw == self.eof:
             if len(self.filestack) == 0:
-                return ""
+                return self.eof
             else:
                 self.pop_source()
                 raw = self.get_token()
-         # Neither inclusion nor EOF
+        # Neither inclusion nor EOF
         if self.debug >= 1:
-            if raw:
+            if raw != self.eof:
                 print "shlex: token=" + `raw`
             else:
                 print "shlex: token=EOF"
         return raw
 
     def read_token(self):
-        "Read a token from the input stream (no pushback or inclusions)"
+        quoted = 0
+        escapedstate = ' '
         while 1:
             nextchar = self.instream.read(1)
             if nextchar == '\n':
@@ -113,35 +140,65 @@ class shlex:
                 elif nextchar in self.whitespace:
                     if self.debug >= 2:
                         print "shlex: I see whitespace in whitespace state"
-                    if self.token:
+                    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:
-                    self.token = nextchar
+                    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:
+                    if self.token or (self.posix and quoted):
                         break   # emit current token
                     else:
                         continue
             elif self.state in self.quotes:
-                self.token = self.token + nextchar
-                if nextchar == self.state:
-                    self.state = ' '
-                    break
-                elif not nextchar:      # end of file
+                quoted = 1
+                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
@@ -150,14 +207,26 @@ class shlex:
                     if self.debug >= 2:
                         print "shlex: I see whitespace in word state"
                     self.state = ' '
-                    if self.token:
+                    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 nextchar in self.wordchars or nextchar in self.quotes:
+                    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 = [nextchar] + self.pushback
@@ -170,6 +239,8 @@ class shlex:
                         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=" + `result`
@@ -182,7 +253,7 @@ class shlex:
         if newfile[0] == '"':
             newfile = newfile[1:-1]
         # This implements cpp-like semantics for relative-path inclusion.
-        if type(self.infile) == type("") and not os.path.isabs(newfile):
+        if type(self.infile) in StringTypes and not os.path.isabs(newfile):
             newfile = os.path.join(os.path.dirname(self.infile), newfile)
         return (newfile, open(newfile, "r"))
 
@@ -194,6 +265,19 @@ class shlex:
             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, posix=1, spaces=1):
+    lex = shlex(s, posix=posix)
+    lex.whitespace_split = spaces
+    return list(lex)
 
 if __name__ == '__main__':
     if len(sys.argv) == 1:
diff --git a/Lib/test/test_shlex.py b/Lib/test/test_shlex.py
new file mode 100644
index 0000000..f8ef88c
--- /dev/null
+++ b/Lib/test/test_shlex.py
@@ -0,0 +1,191 @@
+# -*- coding: iso-8859-1 -*-
+import unittest
+import os, sys
+import shlex
+
+try:
+    from cStringIO import StringIO
+except ImportError:
+    from StringIO import StringIO
+
+
+# The original test data set was from shellwords, by Hartmut Goebel.
+
+data = r"""x|x|
+foo bar|foo|bar|
+ foo bar|foo|bar|
+ foo bar |foo|bar|
+foo   bar    bla     fasel|foo|bar|bla|fasel|
+x y  z              xxxx|x|y|z|xxxx|
+\x bar|\|x|bar|
+\ x bar|\|x|bar|
+\ bar|\|bar|
+foo \x bar|foo|\|x|bar|
+foo \ x bar|foo|\|x|bar|
+foo \ bar|foo|\|bar|
+foo "bar" bla|foo|"bar"|bla|
+"foo" "bar" "bla"|"foo"|"bar"|"bla"|
+"foo" bar "bla"|"foo"|bar|"bla"|
+"foo" bar bla|"foo"|bar|bla|
+foo 'bar' bla|foo|'bar'|bla|
+'foo' 'bar' 'bla'|'foo'|'bar'|'bla'|
+'foo' bar 'bla'|'foo'|bar|'bla'|
+'foo' bar bla|'foo'|bar|bla|
+blurb foo"bar"bar"fasel" baz|blurb|foo"bar"bar"fasel"|baz|
+blurb foo'bar'bar'fasel' baz|blurb|foo'bar'bar'fasel'|baz|
+""|""|
+''|''|
+foo "" bar|foo|""|bar|
+foo '' bar|foo|''|bar|
+foo "" "" "" bar|foo|""|""|""|bar|
+foo '' '' '' bar|foo|''|''|''|bar|
+\""|\|""|
+"\"|"\"|
+"foo\ bar"|"foo\ bar"|
+"foo\\ bar"|"foo\\ bar"|
+"foo\\ bar\"|"foo\\ bar\"|
+"foo\\" bar\""|"foo\\"|bar|\|""|
+"foo\\ bar\" dfadf"|"foo\\ bar\"|dfadf"|
+"foo\\\ bar\" dfadf"|"foo\\\ bar\"|dfadf"|
+"foo\\\x bar\" dfadf"|"foo\\\x bar\"|dfadf"|
+"foo\x bar\" dfadf"|"foo\x bar\"|dfadf"|
+\''|\|''|
+'foo\ bar'|'foo\ bar'|
+'foo\\ bar'|'foo\\ bar'|
+"foo\\\x bar\" df'a\ 'df'|"foo\\\x bar\"|df'a|\|'df'|
+\"foo"|\|"foo"|
+\"foo"\x|\|"foo"|\|x|
+"foo\x"|"foo\x"|
+"foo\ "|"foo\ "|
+foo\ xx|foo|\|xx|
+foo\ x\x|foo|\|x|\|x|
+foo\ x\x\""|foo|\|x|\|x|\|""|
+"foo\ x\x"|"foo\ x\x"|
+"foo\ x\x\\"|"foo\ x\x\\"|
+"foo\ x\x\\""foobar"|"foo\ x\x\\"|"foobar"|
+"foo\ x\x\\"\''"foobar"|"foo\ x\x\\"|\|''|"foobar"|
+"foo\ x\x\\"\'"fo'obar"|"foo\ x\x\\"|\|'"fo'|obar"|
+"foo\ x\x\\"\'"fo'obar" 'don'\''t'|"foo\ x\x\\"|\|'"fo'|obar"|'don'|\|''|t'|
+'foo\ bar'|'foo\ bar'|
+'foo\\ bar'|'foo\\ bar'|
+foo\ bar|foo|\|bar|
+foo#bar\nbaz|foobaz|
+:-) ;-)|:|-|)|;|-|)|
+áéíóú|á|é|í|ó|ú|
+"""
+
+posix_data = r"""x|x|
+foo bar|foo|bar|
+ foo bar|foo|bar|
+ foo bar |foo|bar|
+foo   bar    bla     fasel|foo|bar|bla|fasel|
+x y  z              xxxx|x|y|z|xxxx|
+\x bar|x|bar|
+\ x bar| x|bar|
+\ bar| bar|
+foo \x bar|foo|x|bar|
+foo \ x bar|foo| x|bar|
+foo \ bar|foo| bar|
+foo "bar" bla|foo|bar|bla|
+"foo" "bar" "bla"|foo|bar|bla|
+"foo" bar "bla"|foo|bar|bla|
+"foo" bar bla|foo|bar|bla|
+foo 'bar' bla|foo|bar|bla|
+'foo' 'bar' 'bla'|foo|bar|bla|
+'foo' bar 'bla'|foo|bar|bla|
+'foo' bar bla|foo|bar|bla|
+blurb foo"bar"bar"fasel" baz|blurb|foobarbarfasel|baz|
+blurb foo'bar'bar'fasel' baz|blurb|foobarbarfasel|baz|
+""||
+''||
+foo "" bar|foo||bar|
+foo '' bar|foo||bar|
+foo "" "" "" bar|foo||||bar|
+foo '' '' '' bar|foo||||bar|
+\"|"|
+"\""|"|
+"foo\ bar"|foo\ bar|
+"foo\\ bar"|foo\ bar|
+"foo\\ bar\""|foo\ bar"|
+"foo\\" bar\"|foo\|bar"|
+"foo\\ bar\" dfadf"|foo\ bar" dfadf|
+"foo\\\ bar\" dfadf"|foo\\ bar" dfadf|
+"foo\\\x bar\" dfadf"|foo\\x bar" dfadf|
+"foo\x bar\" dfadf"|foo\x bar" dfadf|
+\'|'|
+'foo\ bar'|foo\ bar|
+'foo\\ bar'|foo\\ bar|
+"foo\\\x bar\" df'a\ 'df"|foo\\x bar" df'a\ 'df|
+\"foo|"foo|
+\"foo\x|"foox|
+"foo\x"|foo\x|
+"foo\ "|foo\ |
+foo\ xx|foo xx|
+foo\ x\x|foo xx|
+foo\ x\x\"|foo xx"|
+"foo\ x\x"|foo\ x\x|
+"foo\ x\x\\"|foo\ x\x\|
+"foo\ x\x\\""foobar"|foo\ x\x\foobar|
+"foo\ x\x\\"\'"foobar"|foo\ x\x\'foobar|
+"foo\ x\x\\"\'"fo'obar"|foo\ x\x\'fo'obar|
+"foo\ x\x\\"\'"fo'obar" 'don'\''t'|foo\ x\x\'fo'obar|don't|
+"foo\ x\x\\"\'"fo'obar" 'don'\''t' \\|foo\ x\x\'fo'obar|don't|\|
+'foo\ bar'|foo\ bar|
+'foo\\ bar'|foo\\ bar|
+foo\ bar|foo bar|
+foo#bar\nbaz|foo|baz|
+:-) ;-)|:-)|;-)|
+áéíóú|áéíóú|
+"""
+
+class ShlexTest(unittest.TestCase):
+    def setUp(self):
+        self.data = [x.split("|")[:-1]
+                     for x in data.splitlines()]
+        self.posix_data = [x.split("|")[:-1]
+                           for x in posix_data.splitlines()]
+        for item in self.data:
+            item[0] = item[0].replace(r"\n", "\n")
+        for item in self.posix_data:
+            item[0] = item[0].replace(r"\n", "\n")
+
+    def splitTest(self, data, posix, spaces):
+        for i in range(len(data)):
+            l = shlex.split(data[i][0], posix=posix, spaces=spaces)
+            self.assertEqual(l, data[i][1:],
+                             "%s: %s != %s" %
+                             (data[i][0], l, data[i][1:]))
+
+    def oldSplit(self, s):
+        ret = []
+        lex = shlex.shlex(StringIO(s))
+        tok = lex.get_token()
+        while tok:
+            ret.append(tok)
+            tok = lex.get_token()
+        return ret
+    
+    def testSplit(self):
+        """Test data splitting with non-posix parser"""
+        self.splitTest(self.data, posix=0, spaces=0) 
+
+    def testSplitPosix(self):
+        """Test data splitting with posix parser"""
+        self.splitTest(self.posix_data, posix=1, spaces=1) 
+
+    def testCompat(self):
+        """Test compatibility interface"""
+        for i in range(len(self.data)):
+            l = self.oldSplit(self.data[i][0])
+            self.assertEqual(l, self.data[i][1:],
+                             "%s: %s != %s" %
+                             (self.data[i][0], l, self.data[i][1:]))
+
+# Allow this test to be used with old shlex.py
+if not getattr(shlex, "split", None):
+    for methname in dir(ShlexTest):
+        if methname.startswith("test") and methname != "testCompat":
+            delattr(ShlexTest, methname)
+
+if __name__ == "__main__":
+    unittest.main()