popen.3: RETURN VALUE: describe successful case

- resolves #1331312

man-pages.spec

@@ -7,7 +7,7 @@
 Summary: Linux kernel and C library user-space interface documentation
 Name: man-pages
 Version: 4.05
-Release: 2%{?dist}
+Release: 3%{?dist}
 License: GPL+ and GPLv2+ and BSD and MIT and Copyright only and IEEE
 Group: Documentation
 URL: http://www.kernel.org/doc/man-pages/
@@ -36,6 +36,9 @@ Patch21: man-pages-3.42-close.patch
 # Resolves: #1330663
 Patch22: clone.2-fork.2-document-erestartnointr.patch
 
+# Resolves: #1331312
+Patch23: popen.2-return-value-describe-successful-case.patch
+
 %description
 A large collection of manual pages from the Linux Documentation Project (LDP).
 
@@ -44,6 +47,7 @@ A large collection of manual pages from the Linux Documentation Project (LDP).
 
 %patch21 -p1
 %patch22 -p1
+%patch23 -p1
 
 # rename posix README so we don't have conflict
 %{__mv} %{posix_name}/README %{posix_name}/%{posix_name}.README
@@ -80,6 +84,10 @@ popd
 %{_mandir}/man*/*
 
 %changelog
+* Tue May 10 2016 Nikola Forró <nforro@redhat.com> - 4.05-3
+- popen.3: RETURN VALUE: describe successful case
+  resolves #1331312
+
 * Tue May 10 2016 Nikola Forró <nforro@redhat.com> - 4.05-2
 - clone.2, fork.2: document ERESTARTNOINTR error code
   resolves #1330663

popen.2-return-value-describe-successful-case.patch

@@ -0,0 +1,67 @@
+From ea5bce080a2a7faacdcb3ca52185003e6e225b87 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Nikola=20Forr=C3=B3?= <nforro@redhat.com>
+Date: Thu, 28 Apr 2016 16:54:29 +0200
+Subject: [PATCH] popen.3: RETURN VALUE: describe successful case
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Reference:
+http://pubs.opengroup.org/onlinepubs/9699919799/functions/popen.html
+http://pubs.opengroup.org/onlinepubs/9699919799/functions/pclose.html
+
+Signed-off-by: Nikola Forró <nforro@redhat.com>
+---
+ man3/popen.3 | 25 ++++++++++++++-----------
+ 1 file changed, 14 insertions(+), 11 deletions(-)
+
+diff --git a/man3/popen.3 b/man3/popen.3
+index f075581..bafa42c 100644
+--- a/man3/popen.3
++++ b/man3/popen.3
+@@ -123,17 +123,18 @@ function waits for the associated process to terminate and returns the exit
+ status of the command as returned by
+ .BR wait4 (2).
+ .SH RETURN VALUE
+-The
+-.BR popen ()
+-function returns NULL if the
++.BR popen ():
++on success, returns a pointer to an open stream that
++can be used to read or write to the pipe;
++if the
+ .BR fork (2)
+ or
+ .BR pipe (2)
+-calls fail, or if it cannot allocate memory.
+-.PP
+-The
+-.BR pclose ()
+-function returns \-1 if
++calls fail, or if the function cannot allocate memory,
++NULL is returned.
++
++.BR pclose ():
++on success, returns the exit status of the command; if
+ .\" These conditions actually give undefined results, so I commented
+ .\" them out.
+ .\" .I stream
+@@ -141,10 +142,12 @@ function returns \-1 if
+ .\".I stream
+ .\" already "pclose()d", or if
+ .BR wait4 (2)
+-returns an error, or some other error is detected.
+-In the event of an error, these functions set
++returns an error, or some other error is detected,
++\-1 is returned.
++.PP
++Both functions set
+ .I errno
+-to indicate the cause of the error.
++to an appropriate value in the case of an error.
+ .SH ERRORS
+ The
+ .BR popen ()
+-- 
+2.7.4
+