[Python-checkins] r75143 - in python/trunk: Doc/library/subprocess.rst Lib/os.py Lib/subprocess.py Lib/test/test_popen2.py Misc/NEWS

Tue Sep 29 21:10:15 CEST 2009

Author: philip.jenvey
Date: Tue Sep 29 21:10:15 2009
New Revision: 75143
Log:
#5329: fix os.popen* regression from 2.5: don't execute commands as a sequence
through the shell. also document the correct subprocess replacement for this
case
patch from Jean-Paul Calderone and Jani Hakala
Modified:
 python/trunk/Doc/library/subprocess.rst
 python/trunk/Lib/os.py
 python/trunk/Lib/subprocess.py
 python/trunk/Lib/test/test_popen2.py
 python/trunk/Misc/NEWS
Modified: python/trunk/Doc/library/subprocess.rst
==============================================================================

--- python/trunk/Doc/library/subprocess.rst	(original)
+++ python/trunk/Doc/library/subprocess.rst	Tue Sep 29 21:10:15 2009
@@ -457,21 +457,21 @@
 
 ::
 
- pipe = os.popen(cmd, 'r', bufsize)
+ pipe = os.popen("cmd", 'r', bufsize)
 ==>
- pipe = Popen(cmd, shell=True, bufsize=bufsize, stdout=PIPE).stdout
+ pipe = Popen("cmd", shell=True, bufsize=bufsize, stdout=PIPE).stdout
 
 ::
 
- pipe = os.popen(cmd, 'w', bufsize)
+ pipe = os.popen("cmd", 'w', bufsize)
 ==>
- pipe = Popen(cmd, shell=True, bufsize=bufsize, stdin=PIPE).stdin
+ pipe = Popen("cmd", shell=True, bufsize=bufsize, stdin=PIPE).stdin
 
 ::
 
- (child_stdin, child_stdout) = os.popen2(cmd, mode, bufsize)
+ (child_stdin, child_stdout) = os.popen2("cmd", mode, bufsize)
 ==>
- p = Popen(cmd, shell=True, bufsize=bufsize,
+ p = Popen("cmd", shell=True, bufsize=bufsize,
 stdin=PIPE, stdout=PIPE, close_fds=True)
 (child_stdin, child_stdout) = (p.stdin, p.stdout)
 
@@ -479,9 +479,9 @@
 
 (child_stdin,
 child_stdout,
- child_stderr) = os.popen3(cmd, mode, bufsize)
+ child_stderr) = os.popen3("cmd", mode, bufsize)
 ==>
- p = Popen(cmd, shell=True, bufsize=bufsize,
+ p = Popen("cmd", shell=True, bufsize=bufsize,
 stdin=PIPE, stdout=PIPE, stderr=PIPE, close_fds=True)
 (child_stdin,
 child_stdout,
@@ -489,21 +489,33 @@
 
 ::
 
- (child_stdin, child_stdout_and_stderr) = os.popen4(cmd, mode, bufsize)
+ (child_stdin, child_stdout_and_stderr) = os.popen4("cmd", mode,
+ bufsize)
 ==>
- p = Popen(cmd, shell=True, bufsize=bufsize,
+ p = Popen("cmd", shell=True, bufsize=bufsize,
 stdin=PIPE, stdout=PIPE, stderr=STDOUT, close_fds=True)
 (child_stdin, child_stdout_and_stderr) = (p.stdin, p.stdout)
 
+On Unix, os.popen2, os.popen3 and os.popen4 also accept a sequence as
+the command to execute, in which case arguments will be passed
+directly to the program without shell intervention. This usage can be
+replaced as follows::
+
+ (child_stdin, child_stdout) = os.popen2(["/bin/ls", "-l"], mode,
+ bufsize)
+ ==>
+ p = Popen(["/bin/ls", "-l"], bufsize=bufsize, stdin=PIPE, stdout=PIPE)
+ (child_stdin, child_stdout) = (p.stdin, p.stdout)
+
 Return code handling translates as follows::
 
- pipe = os.popen(cmd, 'w')
+ pipe = os.popen("cmd", 'w')
 ...
 rc = pipe.close()
- if rc != None and rc % 256:
+ if rc != None and rc % 256:
 print "There were some errors"
 ==>
- process = Popen(cmd, 'w', stdin=PIPE)
+ process = Popen("cmd", 'w', shell=True, stdin=PIPE)
 ...
 process.stdin.close()
 if process.wait() != 0:
@@ -513,11 +525,6 @@
 Replacing functions from the :mod:`popen2` module
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-.. note::
-
- If the cmd argument to popen2 functions is a string, the command is executed
- through /bin/sh. If it is a list, the command is directly executed.
-
 ::
 
 (child_stdout, child_stdin) = popen2.popen2("somestring", bufsize, mode)
@@ -526,9 +533,12 @@
 stdin=PIPE, stdout=PIPE, close_fds=True)
 (child_stdout, child_stdin) = (p.stdout, p.stdin)
 
-::
+On Unix, popen2 also accepts a sequence as the command to execute, in
+which case arguments will be passed directly to the program without
+shell intervention. This usage can be replaced as follows::
 
- (child_stdout, child_stdin) = popen2.popen2(["mycmd", "myarg"], bufsize, mode)
+ (child_stdout, child_stdin) = popen2.popen2(["mycmd", "myarg"], bufsize,
+ mode)
 ==>
 p = Popen(["mycmd", "myarg"], bufsize=bufsize,
 stdin=PIPE, stdout=PIPE, close_fds=True)
Modified: python/trunk/Lib/os.py
==============================================================================
--- python/trunk/Lib/os.py	(original)
+++ python/trunk/Lib/os.py	Tue Sep 29 21:10:15 2009
@@ -666,8 +666,9 @@
 
 import subprocess
 PIPE = subprocess.PIPE
- p = subprocess.Popen(cmd, shell=True, bufsize=bufsize,
- stdin=PIPE, stdout=PIPE, close_fds=True)
+ p = subprocess.Popen(cmd, shell=isinstance(cmd, basestring),
+ bufsize=bufsize, stdin=PIPE, stdout=PIPE,
+ close_fds=True)
 return p.stdin, p.stdout
 __all__.append("popen2")
 
@@ -685,9 +686,9 @@
 
 import subprocess
 PIPE = subprocess.PIPE
- p = subprocess.Popen(cmd, shell=True, bufsize=bufsize,
- stdin=PIPE, stdout=PIPE, stderr=PIPE,
- close_fds=True)
+ p = subprocess.Popen(cmd, shell=isinstance(cmd, basestring),
+ bufsize=bufsize, stdin=PIPE, stdout=PIPE,
+ stderr=PIPE, close_fds=True)
 return p.stdin, p.stdout, p.stderr
 __all__.append("popen3")
 
@@ -705,8 +706,8 @@
 
 import subprocess
 PIPE = subprocess.PIPE
- p = subprocess.Popen(cmd, shell=True, bufsize=bufsize,
- stdin=PIPE, stdout=PIPE,
+ p = subprocess.Popen(cmd, shell=isinstance(cmd, basestring),
+ bufsize=bufsize, stdin=PIPE, stdout=PIPE,
 stderr=subprocess.STDOUT, close_fds=True)
 return p.stdin, p.stdout
 __all__.append("popen4")
Modified: python/trunk/Lib/subprocess.py
==============================================================================
--- python/trunk/Lib/subprocess.py	(original)
+++ python/trunk/Lib/subprocess.py	Tue Sep 29 21:10:15 2009
@@ -298,54 +298,80 @@
 
 Replacing os.popen*
 -------------------
-pipe = os.popen(cmd, mode='r', bufsize)
+pipe = os.popen("cmd", mode='r', bufsize)
 ==>
-pipe = Popen(cmd, shell=True, bufsize=bufsize, stdout=PIPE).stdout
+pipe = Popen("cmd", shell=True, bufsize=bufsize, stdout=PIPE).stdout
 
-pipe = os.popen(cmd, mode='w', bufsize)
+pipe = os.popen("cmd", mode='w', bufsize)
 ==>
-pipe = Popen(cmd, shell=True, bufsize=bufsize, stdin=PIPE).stdin
+pipe = Popen("cmd", shell=True, bufsize=bufsize, stdin=PIPE).stdin
 
 
-(child_stdin, child_stdout) = os.popen2(cmd, mode, bufsize)
+(child_stdin, child_stdout) = os.popen2("cmd", mode, bufsize)
 ==>
-p = Popen(cmd, shell=True, bufsize=bufsize,
+p = Popen("cmd", shell=True, bufsize=bufsize,
 stdin=PIPE, stdout=PIPE, close_fds=True)
 (child_stdin, child_stdout) = (p.stdin, p.stdout)
 
 
 (child_stdin,
 child_stdout,
- child_stderr) = os.popen3(cmd, mode, bufsize)
+ child_stderr) = os.popen3("cmd", mode, bufsize)
 ==>
-p = Popen(cmd, shell=True, bufsize=bufsize,
+p = Popen("cmd", shell=True, bufsize=bufsize,
 stdin=PIPE, stdout=PIPE, stderr=PIPE, close_fds=True)
 (child_stdin,
 child_stdout,
 child_stderr) = (p.stdin, p.stdout, p.stderr)
 
 
-(child_stdin, child_stdout_and_stderr) = os.popen4(cmd, mode, bufsize)
+(child_stdin, child_stdout_and_stderr) = os.popen4("cmd", mode,
+ bufsize)
 ==>
-p = Popen(cmd, shell=True, bufsize=bufsize,
+p = Popen("cmd", shell=True, bufsize=bufsize,
 stdin=PIPE, stdout=PIPE, stderr=STDOUT, close_fds=True)
 (child_stdin, child_stdout_and_stderr) = (p.stdin, p.stdout)
 
+On Unix, os.popen2, os.popen3 and os.popen4 also accept a sequence as
+the command to execute, in which case arguments will be passed
+directly to the program without shell intervention. This usage can be
+replaced as follows:
+
+(child_stdin, child_stdout) = os.popen2(["/bin/ls", "-l"], mode,
+ bufsize)
+==>
+p = Popen(["/bin/ls", "-l"], bufsize=bufsize, stdin=PIPE, stdout=PIPE)
+(child_stdin, child_stdout) = (p.stdin, p.stdout)
+
+Return code handling translates as follows:
+
+pipe = os.popen("cmd", 'w')
+...
+rc = pipe.close()
+if rc != None and rc % 256:
+ print "There were some errors"
+==>
+process = Popen("cmd", 'w', shell=True, stdin=PIPE)
+...
+process.stdin.close()
+if process.wait() != 0:
+ print "There were some errors"
+
 
 Replacing popen2.*
 ------------------
-Note: If the cmd argument to popen2 functions is a string, the command
-is executed through /bin/sh. If it is a list, the command is directly
-executed.
-
 (child_stdout, child_stdin) = popen2.popen2("somestring", bufsize, mode)
 ==>
 p = Popen(["somestring"], shell=True, bufsize=bufsize
 stdin=PIPE, stdout=PIPE, close_fds=True)
 (child_stdout, child_stdin) = (p.stdout, p.stdin)
 
+On Unix, popen2 also accepts a sequence as the command to execute, in
+which case arguments will be passed directly to the program without
+shell intervention. This usage can be replaced as follows:
 
-(child_stdout, child_stdin) = popen2.popen2(["mycmd", "myarg"], bufsize, mode)
+(child_stdout, child_stdin) = popen2.popen2(["mycmd", "myarg"], bufsize,
+ mode)
 ==>
 p = Popen(["mycmd", "myarg"], bufsize=bufsize,
 stdin=PIPE, stdout=PIPE, close_fds=True)
Modified: python/trunk/Lib/test/test_popen2.py
==============================================================================
--- python/trunk/Lib/test/test_popen2.py	(original)
+++ python/trunk/Lib/test/test_popen2.py	Tue Sep 29 21:10:15 2009
@@ -78,6 +78,14 @@
 
 def test_os_popen2(self):
 # same test as test_popen2(), but using the os.popen*() API
+ if os.name == 'posix':
+ w, r = os.popen2([self.cmd])
+ self.validate_output(self.teststr, self.expected, r, w)
+
+ w, r = os.popen2(["echo", self.teststr])
+ got = r.read()
+ self.assertEquals(got, self.teststr + "\n")
+
 w, r = os.popen2(self.cmd)
 self.validate_output(self.teststr, self.expected, r, w)
 
@@ -87,9 +95,27 @@
 w, r, e = os.popen3([self.cmd])
 self.validate_output(self.teststr, self.expected, r, w, e)
 
+ w, r, e = os.popen3(["echo", self.teststr])
+ got = r.read()
+ self.assertEquals(got, self.teststr + "\n")
+ got = e.read()
+ self.assertFalse(got, "unexpected %r on stderr" % got)
+
 w, r, e = os.popen3(self.cmd)
 self.validate_output(self.teststr, self.expected, r, w, e)
 
+ def test_os_popen4(self):
+ if os.name == 'posix':
+ w, r = os.popen4([self.cmd])
+ self.validate_output(self.teststr, self.expected, r, w)
+
+ w, r = os.popen4(["echo", self.teststr])
+ got = r.read()
+ self.assertEquals(got, self.teststr + "\n")
+
+ w, r = os.popen4(self.cmd)
+ self.validate_output(self.teststr, self.expected, r, w)
+
 
 def test_main():
 run_unittest(Popen2Test)
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS	(original)
+++ python/trunk/Misc/NEWS	Tue Sep 29 21:10:15 2009
@@ -12,6 +12,10 @@
 Core and Builtins
 -----------------
 
+- Issue #5329: Fix os.popen* regression from 2.5 with commands as a
+ sequence running through the shell. Patch by Jean-Paul Calderone
+ and Jani Hakala.
+
 - Issue #7019: Raise ValueError when unmarshalling bad long data, instead
 of producing internally inconsistent Python longs.
 
