[Jython-checkins] jython: Remove -E from jython.py (fixes #2707) and improve --print on Linux

[jeff.allen]

https://hg.python.org/jython/rev/38824a8816a8
changeset:   8186:38824a8816a8
user:        Jeff Allen <ja.py at farowl.co.uk>
date:        Wed Sep 26 22:47:02 2018 +0100
summary:
  Remove -E from jython.py (fixes #2707) and improve --print on Linux

Adds quoting and escaping to the output from the launcher when --print
is specified, lost in a previous change, sufficient for
test_jython_launcher to pass. See #2686.

The shebang line of jython.py was not valid on Linux where the entire
line after the first space is treated as one argument, thus
python2.7 is all we can have after usr/bin/env. See #2707.

files:
  src/shell/jython.py |  39 +++++++++++++++++++++++++++-----
  1 files changed, 33 insertions(+), 6 deletions(-)


diff --git a/src/shell/jython.py b/src/shell/jython.py
--- a/src/shell/jython.py
+++ b/src/shell/jython.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7 -E
+#!/usr/bin/env python2.7
 # -*- coding: utf-8 -*-
 
 # Launch script for Jython. It may be run directly (note the shebang line), but
@@ -13,10 +13,8 @@
 # Developers' Guide).
 
 import glob
-import inspect
 import os
 import os.path
-import pipes
 import shlex
 import subprocess
 import sys
@@ -219,8 +217,8 @@
             # Frozen. Let it go with the executable path.
             bytes_path = sys.executable
         else:
-            # Not frozen. Any object defined in this file will do. 
-            bytes_path = inspect.getfile(JythonCommand)
+            # Not frozen. Use the __file__ of this module.. 
+            bytes_path = __file__
         # Python 2 thinks in bytes. Carefully normalise in Unicode.
         path = os.path.realpath(bytes_path.decode(ENCODING))
         try:
@@ -499,6 +497,33 @@
         opts = shlex.split(opts)
     return decode_list(opts)
 
+def maybe_quote(s):
+    """ Enclose the string argument in single quotes if it looks like it needs it.
+        Spaces and quotes will trigger; single quotes in the argument are escaped.
+        This is only used to compose the --print output so need only satisfy shlex.
+    """
+    NEED_QUOTE = u" \t\"\\'"
+    clean = True
+    for c in s:
+        if c in NEED_QUOTE:
+            clean = False
+            break
+    if clean: return s
+    # Something needs quoting or escaping.
+    QUOTE = u"'"
+    ESC = u"\\"
+    arg = [QUOTE]
+    for c in s:
+        if c == QUOTE:
+            arg.append(QUOTE)
+            arg.append(ESC)
+            arg.append(QUOTE)
+        elif c == ESC:
+            arg.append(ESC)
+        arg.append(c)
+    arg.append(QUOTE)
+    return ''.join(arg)
+
 def main(sys_args):
     # The entire program must work in Unicode
     sys_args = decode_list(sys_args)
@@ -532,7 +557,9 @@
             # Normally used for a byte strings but Python is tolerant :)
             command_line = subprocess.list2cmdline(command)
         else:
-            # Just concatenate with spaces
+            # Transform any element that seems to need quotes
+            command = map(maybe_quote, command)
+            # Now concatenate with spaces
             command_line = u" ".join(command)
         # It is possible the Unicode cannot be encoded for the console
         enc = sys.stdout.encoding or 'ascii'

-- 
Repository URL: https://hg.python.org/jython