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 9a3f3de..65e9bb6 100644 (file)
--- a/bindings/perl-piped/RRDp.pm
+++ b/bindings/perl-piped/RRDp.pm
@@ -16,7 +16,7 @@ $answer = B<RRD::read>
 
 $status = B<RRD::end>
 
-B<$RRDp::user>,  B<$RRDp::sys>, B<$RRDp::real>
+B<$RRDp::user>,  B<$RRDp::sys>, B<$RRDp::real>, B<$RRDp::error_mode>, B<$RRDp::error>
 
 =head1 DESCRIPTION
 
@@ -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
@@ -66,9 +69,19 @@ 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>
+
+If you set the variable $RRDp::error_mode to the value 'catch' before you run RRDp::read a potential
+ERROR message will not cause the program to abort but will be returned in this variable. If no error
+occurs the variable will be empty.
+
+ $RRDp::error_mode = 'catch';
+ RRDp::cmd qw(info file.rrd);
+ print $RRDp::error if $RRDp::error;
+
 =back
 
 
@@ -89,9 +102,10 @@ For more information on how to use RRDtool, check the manpages.
 
 =head1 AUTHOR
 
-Tobias Oetiker <oetiker@ee.ethz.ch>
+Tobias Oetiker <tobi@oetiker.ch>
 
 =cut
+
 #'  this is to make cperl.el happy
 
 use strict;
@@ -110,7 +124,7 @@ sub cmd (@);
 sub end ();
 sub read ();
 
-$VERSION=1.2001;
+$VERSION=1.4002;
 
 sub start ($){
   croak "rrdtool is already running"
@@ -128,6 +142,7 @@ sub start ($){
 sub read () {
   croak "RRDp::read can only be called after RRDp::cmd" 
     unless $Sequence eq 'C';
+  $RRDp::error = undef;
   $Sequence = 'R';
   my $inmask = 0;
   my $srbuf;
@@ -135,7 +150,6 @@ sub read () {
   my $buffer;
   my $nfound;
   my $timeleft;
-  my $ERR = 0;
   vec($inmask,fileno(RRDreadHand),1) = 1; # setup select mask for Reader
   while (1) {
     my $rout;    
@@ -148,14 +162,18 @@ sub read () {
     $minibuf .= $srbuf;
     while ($minibuf =~ s|^(.+?)\n||s) {
       my $line = $1;
-      # print $line,"\n";
-      if ($line =~  m|^ERROR|) {
-       croak $line;
-       $ERR = 1;
+      # print $line,"\n";      
+      $RRDp::error = undef;
+      if ($line =~  m|^ERROR|) {       
+       $RRDp::error_mode eq 'catch' ? $RRDp::error = $line : croak $line;
+        $RRDp::sys = undef;
+        $RRDp::user = undef;
+        $RRDp::real = undef;
+       return undef;
       } 
-      elsif ($line =~ m|^OK u:([\d\.]+) s:([\d\.]+) r:([\d\.]+)|){
+      elsif ($line =~ m|^OK(?: u:([\d\.]+) s:([\d\.]+) r:([\d\.]+))?|){
        ($RRDp::sys,$RRDp::user,$RRDp::real)=($1,$2,$3);
-       return $ERR == 1 ? undef : \$buffer;
+       return \$buffer;
       } else {
        $buffer .= $line. "\n";
       }
@@ -172,6 +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";
 }