Document that on Unix, the 'cmd' argument to the os.popen2/3/4 and

popen2.popen2/3/4 functions can be a sequence. All texts are a variation on the
following:

On \UNIX, \var{cmd} may be a sequence, in which case arguments will be passed
directly to the program without shell intervention (as with
\function{os.spawnv()}). If \var{cmd} is a string it will be passed to the shell
(as with \function{os.system()}).

1 files changed, 18 insertions, 0 deletions

diff --git a/Lib/os.py b/Lib/os.py
index 8839c10..65b1830 100644
--- a/Lib/os.py
+++ b/Lib/os.py
@@ -611,6 +611,12 @@ otherwise return -SIG, where SIG is the signal that killed it. """
 if _exists("fork"):
     if not _exists("popen2"):
         def popen2(cmd, mode="t", bufsize=-1):
+            """Execute the shell command 'cmd' in a sub-process.  On UNIX, 'cmd'
+            may be a sequence, in which case arguments will be passed directly to
+            the program without shell intervention (as with os.spawnv()).  If 'cmd'
+            is a string it will be passed to the shell (as with os.system()). If
+            'bufsize' is specified, it sets the buffer size for the I/O pipes.  The
+            file objects (child_stdin, child_stdout) are returned."""
             import popen2
             stdout, stdin = popen2.popen2(cmd, bufsize)
             return stdin, stdout
@@ -618,6 +624,12 @@ if _exists("fork"):
 
     if not _exists("popen3"):
         def popen3(cmd, mode="t", bufsize=-1):
+            """Execute the shell command 'cmd' in a sub-process.  On UNIX, 'cmd'
+            may be a sequence, in which case arguments will be passed directly to
+            the program without shell intervention (as with os.spawnv()).  If 'cmd'
+            is a string it will be passed to the shell (as with os.system()). If
+            'bufsize' is specified, it sets the buffer size for the I/O pipes.  The
+            file objects (child_stdin, child_stdout, child_stderr) are returned."""
             import popen2
             stdout, stdin, stderr = popen2.popen3(cmd, bufsize)
             return stdin, stdout, stderr
@@ -625,6 +637,12 @@ if _exists("fork"):
 
     if not _exists("popen4"):
         def popen4(cmd, mode="t", bufsize=-1):
+            """Execute the shell command 'cmd' in a sub-process.  On UNIX, 'cmd'
+            may be a sequence, in which case arguments will be passed directly to
+            the program without shell intervention (as with os.spawnv()).  If 'cmd'
+            is a string it will be passed to the shell (as with os.system()). If
+            'bufsize' is specified, it sets the buffer size for the I/O pipes.  The
+            file objects (child_stdin, child_stdout_stderr) are returned."""
             import popen2
             stdout, stdin = popen2.popen4(cmd, bufsize)
             return stdin, stdout