From 098d7fae39fea0adc976edb7c1060054be4b467e Mon Sep 17 00:00:00 2001 From: Fred Drake Date: Tue, 11 Sep 2001 19:56:51 +0000 Subject: [PATCH] Document clearly that the only way to retrieve the return code from the child processes is to use the Popen3 and Popen4 classes. This fixes SF bug #460512. --- Doc/lib/libos.tex | 6 ++++++ Doc/lib/libpopen2.tex | 7 +++++++ 2 files changed, 13 insertions(+) diff --git a/Doc/lib/libos.tex b/Doc/lib/libos.tex index 16f36908ed..1c3a584bf8 100644 --- a/Doc/lib/libos.tex +++ b/Doc/lib/libos.tex @@ -315,6 +315,12 @@ specified, it specifies the buffer size for the I/O pipes. objects should be opened in binary or text mode. The default value for \var{mode} is \code{'t'}. +These methods do not make it possible to retrieve the return code from +the child processes. The only way to control the input and output +streams and also retrieve the return codes is to use the +\class{Popen3} and \class{Popen4} classes from the \refmodule{popen2} +module; these are only available on \UNIX. + \begin{funcdesc}{popen2}{cmd\optional{, mode\optional{, bufsize}}} Executes \var{cmd} as a sub-process. Returns the file objects \code{(\var{child_stdin}, \var{child_stdout})}. diff --git a/Doc/lib/libpopen2.tex b/Doc/lib/libpopen2.tex index add0af130c..8cdf0f5b76 100644 --- a/Doc/lib/libpopen2.tex +++ b/Doc/lib/libpopen2.tex @@ -24,6 +24,13 @@ this is needed to determine whether the file objects should be opened in binary or text mode. The default value for \var{mode} is \code{'t'}. +The only way to retrieve the return codes for the child processes is +by using the \method{poll()} or \method{wait()} methods on the +\class{Popen3} and \class{Popen4} classes; these are only available on +\UNIX. This information is not available when using the +\function{popen2()}, \function{popen3()}, and \function{popen4()} +functions, or the equivalent functions in the \refmodule{os} module. + \begin{funcdesc}{popen2}{cmd\optional{, bufsize\optional{, mode}}} Executes \var{cmd} as a sub-process. Returns the file objects \code{(\var{child_stdout}, \var{child_stdin})}. -- 2.40.0