[PATCH 2/2] docs: mention ksh file descriptor limitation

[Eric Blake]

* doc/autoconf.texi (File Descriptors): Document issue with fd 10
and above.
Reported by Ralf Wildenhues.
---
 ChangeLog         |    5 +++++
 doc/autoconf.texi |   14 ++++++++++++++
 2 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 278a565..0ef1fd3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2010-07-29  Eric Blake  <address@hidden>

+       docs: mention ksh file descriptor limitation
+       * doc/autoconf.texi (File Descriptors): Document issue with fd 10
+       and above.
+       Reported by Ralf Wildenhues.
+
        docs: mention cd limitation
        * doc/autoconf.texi (Limitations of Builtins) <cd>: Document
        issues with empty argument.
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 493b9dc..7e804a7 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -15041,6 +15041,20 @@ File Descriptors
 obsolete, so it's now safe to treat file descriptors 3 and 4 like any
 other file descriptors.

+On the other hand, you can't portably use multi-digit file descriptors.
+Solaris @command{ksh} doesn't understand any file descriptor larger than
address@hidden:
+
address@hidden
+$ @kbd{bash -c 'exec 10>&-'; echo $?}
+0
+$ @kbd{ksh -c 'exec 9>&-'; echo $?}
+0
+$ @kbd{ksh -c 'exec 10>&-'; echo $?}
+ksh[1]: exec: 10: not found
+127
address@hidden example
+
 @node File System Conventions
 @section File System Conventions
 @cindex File system conventions
-- 
1.7.2