Merged revisions 75143 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r75143 | philip.jenvey | 2009-09-29 12:10:15 -0700 (Tue, 29 Sep 2009) | 5 lines

  #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
........

1 files changed, 30 insertions, 20 deletions

diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index 2bc8f74..c6bd07b 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -418,21 +418,21 @@ Replacing :func:`os.popen`, :func:`os.popen2`, :func:`os.popen3`
 
 ::
 
-   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)
 
@@ -440,9 +440,9 @@ Replacing :func:`os.popen`, :func:`os.popen2`, :func:`os.popen3`
 
    (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,
@@ -450,21 +450,33 @@ Replacing :func:`os.popen`, :func:`os.popen2`, :func:`os.popen3`
 
 ::
 
-   (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:
@@ -474,11 +486,6 @@ Return code handling translates as follows::
 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)
@@ -487,9 +494,12 @@ Replacing functions from the :mod:`popen2` module
              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)