prepare for the release of rrdtool-1.4.2

[rrdtool.git] / bindings / perl-piped / RRDp.pm

diff --git a/bindings/perl-piped/RRDp.pm b/bindings/perl-piped/RRDp.pm
index a99e56e..65e9bb6 100644 (file)
--- a/bindings/perl-piped/RRDp.pm
+++ b/bindings/perl-piped/RRDp.pm
@@ -42,9 +42,12 @@ start RRDtool. The argument must be the path to the RRDtool executable
 
 =item B<RRDp::cmd> I<rrdtool commandline>
 
-pass commands on to RRDtool. check the RRDtool documentation for
+pass commands on to RRDtool. Check the RRDtool documentation for
 more info on the RRDtool commands.
 
+B<Note>: Due to design limitations, B<RRDp::cmd> does not support the
+C<graph -> command - use C<graphv -> instead.
+
 =item $answer = B<RRDp::read>
 
 read RRDtool's response to your command. Note that the $answer variable will
@@ -66,7 +69,7 @@ running, System time is the time spend in system calls and real time
 is the total time RRDtool has been running.
 
 The difference between user + system and real is the time spent
-waiting for things like the hard disk and new input from the perl
+waiting for things like the hard disk and new input from the Perl
 script.
 
 =item B<$RRDp::error_mode> and B<$RRDp::error>
@@ -102,6 +105,7 @@ For more information on how to use RRDtool, check the manpages.
 Tobias Oetiker <tobi@oetiker.ch>
 
 =cut
+
 #'  this is to make cperl.el happy
 
 use strict;
@@ -120,7 +124,7 @@ sub cmd (@);
 sub end ();
 sub read ();
 
-$VERSION=1.3000;
+$VERSION=1.4002;
 
 sub start ($){
   croak "rrdtool is already running"
@@ -186,6 +190,13 @@ sub cmd (@){
   }
   $cmd =~ s/\n/ /gs;
   $cmd =~ s/\s/ /gs;
+
+  # The generated graphs aren't necessarily terminated by a newline,
+  # causing RRDp::read() to wait for a line matching '^OK' forever.
+  if ($cmd =~ m/^\s*graph\s+-\s+/) {
+    croak "RRDp does not support the 'graph -' command - "
+        . "use 'graphv -' instead";
+  }
   print RRDwriteHand "$cmd\n";
 }