=head1 NAME
-rrdtool fetch - fetch data from an rrd.
+rrdtool fetch - fetch data from an RRD.
=for html <div align="right"><a href="rrdfetch.pdf">PDF</a> version.</div>
to get data from B<RRD>s. B<fetch> will analyze the B<RRD> and
will try to retrieve the data in the resolution requested.
The data fetched is printed to stdout. I<*UNKNOWN*> data is often
-represented by the string "NaN" depending on your OSs printf
+represented by the string "NaN" depending on your OS's printf
function.
=over 8
=head2 RESOLUTION INTERVAL
-In order to get rrdtool to fetch anything other than the finest resolution RRA
+In order to get RRDtool to fetch anything other than the finest resolution RRA
B<both> the start and end time must be specified on boundaries that are
multiples of the wanted resolution. Consider the following example:
TIME=$(date +%s); RRDRES=900; rrdtool fetch subdata.rrd AVERAGE -r $RRDRES \
-e $(echo $(($TIME/$RRDRES*$RRDRES))) -s e-1h
-Or in perl:
+Or in Perl:
perl -e '$ctime = time; $rrdres = 900; system "rrdtool fetch subdata.rrd AVERAGE \
-r $rrdres -e @{[int($ctime/$rrdres)*$rrdres]} -s e-1h"'
=head2 AT-STYLE TIME SPECIFICATION
-Apart from the traditional I<Seconds since epoch>, rrdtool does also
+Apart from the traditional I<Seconds since epoch>, RRDtool does also
understand at-style time specification. The specification is called
"at-style" after Unix command at(1) that has moderately complex ways
to specify time to run your job at. The at-style specification
reference. B<Now> refers to the current moment (and is also a default
time reference). B<Start> (B<end>) can be used to specify time
relative to the start (end) time for those tools that use these
-categories (rrdfetch, rrdgraph).
+categories (B<rrdfetch>, L<rrdgraph>).
Month and weekday names can be used in their naturally abbreviated form
(e.g., Dec for December, Sun for Sunday, etc.). The words B<now>,
(yes, seconds since 1970 are valid as well)
I<19970703 12:45> -- 12:45 July 3th, 1997
-(not quote standard, but I love this ...)
-
+(my favorite, and its even got an ISO number (8601))
=head1 AUTHOR