.\" gd_metaflush.3.  The gd_metaflush man page.
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.TH gd_metaflush 3 "16 October 2014" "Version 0.9.0" "GETDATA"
.SH NAME
gd_metaflush \(em write modified dirfile metadata to disk
.SH SYNOPSIS
.B #include <getdata.h>
.HP
.nh
.ad l
.BI "int gd_metaflush(DIRFILE *" dirfile );
.hy
.ad n
.SH DESCRIPTION
The
.BR gd_metaflush ()
function flushes all pending metadata changes in the dirfile specified by
.I dirfile 
to disk.  This is accomplished by re-writing the format specification fragments
containing modified metadata, overwriting the existing files.  Format file
fragments which are unchanged are not touched.
.PP
Metadata is written to disk using the current Standards Version as stored in the
.I dirfile
object.  See
.BR gd_dirfile_standards (3)
to change or report the current Standards Version.  If the dirfile metadata
conforms to no known Standards Version, a Standards non-compliant fragment will
be written.
.PP
This function flushes only metadata.  To flush the field data as well, call
.BR gd_sync (3)
instead.
.SH RETURN VALUE
On success, zero is returned.  On error, -1 is returned and the dirfile error is
set to a non-zero error value.  Possible error values are:
.TP 8
.B GD_E_ACCMODE
The supplied dirfile was opened in read-only mode.
.TP
.B GD_E_ALLOC
The library was unable to allocate memory.
.TP
.B GD_E_BAD_DIRFILE
The supplied dirfile was invalid.
.TP
.B GD_E_IO
An I/O error occurred while trying to write modified metadata to disk.
.TP
.B GD_E_LINE_TOO_LONG
While attempting to flush modified metadata to disk, a field specification line
exceeded the maximum allowed length.  On most platforms, the maximum length is
at least 2**31 bytes, so this typically indicates something pathological
happening.
.PP
The dirfile error may be retrieved by calling
.BR gd_error (3).
A descriptive error string for the last error encountered can be obtained from
a call to
.BR gd_error_string (3).
.SH BUGS
When writing metadata using Standards Version 4 or earlier, the reference field
may change, owing to the lack of a
.B /REFERENCE
directive.  A work-around is to upgrade to Standards Version 5 or later.
.SH SEE ALSO
.BR gd_open (3),
.BR gd_close (3),
.BR gd_dirfile_standards (3),
.BR gd_error (3),
.BR gd_error_string (3),
.BR gd_rewrite_fragment (3),
.BR gd_sync (3)