This is not a utility function but rather part of RRDtool's core. --- program/doc/librrd.pod | 82 +++++++++++++++++++++++++---------------------- 1 files changed, 44 insertions(+), 38 deletions(-)
diff --git a/program/doc/librrd.pod b/program/doc/librrd.pod
index 4daa93c..038746c 100644
--- a/program/doc/librrd.pod
+++ b/program/doc/librrd.pod
@@ -16,9 +16,52 @@ B<NOTE:> This document is a work in progress, and should be
considered
incomplete as long as this warning persists. For more information about
the B<librrd> functions, always consult the source code.
+=head1 CORE FUNCTIONS
+
+=over 4
+
+=item B<rrd_dump_cb_r(char *filename, int opt_header, rrd_output_callback_t
cb, void *user)>
+
+In some situations it is necessary to get the output of C<rrd_dump> without
+writing it to a file or the standard output. In such cases an application
+can ask B<rrd_dump_cb_r> to call an user-defined function each time there
+is output to be stored somewhere. This can be used, to e.g. directly feed
+an XML parser with the dumped output or transfer the resulting string
+in memory.
+
+The arguments for B<rrd_dump_cb_r> are the same as for B<rrd_dump_opt_r>
+except that the output filename parameter is replaced by the user-defined
+callback function and an additional parameter for the callback function
+that is passed untouched, i.e. to store information about the callback state
+needed for the user-defined callback to function properly.
+
+Recent versions of B<rrd_dump_opt_r> internally use this callback mechanism
+to write their output to the file provided by the user.
+
+ size_t rrd_dump_opt_cb_fileout(
+ const void *data,
+ size_t len,
+ void *user)
+ {
+ return fwrite(data, 1, len, (FILE *)user);
+ }
+
+The associated call for B<rrd_dump_cb_r> looks like
+
+ res = rrd_dump_cb_r(filename, opt_header,
+ rrd_dump_opt_cb_fileout, (void *)out_file);
+
+where the last parameter specifies the file handle B<rrd_dump_opt_cb_fileout>
+should write to. There's no specific condition for the callback to detect
+when it is called for the first time, nor for the last time. If you require
+this for initialization and cleanup you should do those tasks before and
+after calling B<rrd_dump_cr_r> respectively.
+
+=back
+
=head1 UTILITY FUNCTIONS
-=over
+=over 4
=item B<rrd_random()>
@@ -86,41 +129,4 @@ Insufficient memory was available.
In contrast to L<mkdir(2)>, the function does B<not> fail if C<pathname>
already exists and is a directory.
-=item B<rrd_dump_cr_r(char *filename, int opt_header, rrd_output_callback_t
cb, void *user)>
-
-In some situations it is necessary to get the output of C<rrd_dump> without
-writing it to a file or the standard output. In such cases an application
-can ask B<rrd_dump_cb_r> to call an user-defined function each time there
-is output to be stored somewhere. This can be used, to e.g. directly feed
-an XML parser with the dumped output or transfer the resulting string
-in memory.
-
-The arguments for B<rrd_dump_cb_r> are the same as for B<rrd_dump_opt_r>
-except that the output filename parameter is replaced by the user-defined
-callback function and an additional parameter for the callback function
-that is passed untouched, i.e. to store information about the callback state
-needed for the user-defined callback to function properly.
-
-Recent versions of B<rrd_dump_opt_r> internally use this callback mechanism
-to write their output to the file provided by the user.
-
- size_t rrd_dump_opt_cb_fileout(
- const void *data,
- size_t len,
- void *user)
- {
- return fwrite(data, 1, len, (FILE *)user);
- }
-
-The associated call for B<rrd_dump_cb_r> looks like
-
- res = rrd_dump_cb_r(filename, opt_header,
- rrd_dump_opt_cb_fileout, (void *)out_file);
-
-where the last parameter specifies the file handle B<rrd_dump_opt_cb_fileout>
-should write to. There's no specific condition for the callback to detect
-when it is called for the first time, nor for the last time. If you require
-this for initialization and cleanup you should do those tasks before and
-after calling B<rrd_dump_cr_r> respectively.
-
=back
--
1.6.5.rc2
signature.asc
Description: Digital signature
_______________________________________________ rrd-developers mailing list rrd-developers@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-developers
