gd_metaflush man page

gd_metaflush — write modified Dirfile metadata to disk

Synopsis

#include <getdata.h>

int gd_metaflush(DIRFILE *dirfile);

Description

The gd_metaflush() function flushes all pending metadata changes in the dirfile specified by 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.

Metadata is written to disk using the current Standards Version as stored in the dirfile object.  See 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.

This function flushes only metadata.  To flush the field data as well, call gd_sync(3) instead.

Return Value

On success, zero is returned.  On error, a negative-valued error code is returned.  Possible error codes are:

GD_E_ACCMODE

The supplied dirfile was opened in read-only mode.

GD_E_ALLOC

The library was unable to allocate memory.

GD_E_BAD_DIRFILE

The supplied dirfile was invalid.

GD_E_IO

An I/O error occurred while trying to write modified metadata to disk.

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.

The error code is also stored in the DIRFILE object and may be retrieved after this function returns by calling gd_error(3). A descriptive error string for the error may be obtained by calling gd_error_string(3).

Notes

When writing metadata using Standards Version 4 or earlier, the reference field may change, owing to the lack of a /REFERENCE directive.  A work-around is to upgrade to Standards Version 5 or later.

History

The dirfile_metaflush() function appeared in GetData-0.4.0.

In GetData-0.7.0, this function was renamed to gd_metaflush().

in GetData-0.10.0, the error return from this function changed from -1 to a negative-valued error code.

See Also

gd_close(3), gd_dirfile_standards(3), gd_error(3), gd_error_string(3), gd_open(3), gd_rewrite_fragment(3), gd_sync(3)

Referenced By

gd_add(3), gd_add_alias(3), gd_add_bit(3), gd_add_spec(3), gd_alter_bit(3), gd_alter_entry(3), gd_alter_spec(3), gd_delete(3), gd_dirfile_standards(3), gd_flags(3), gd_flush(3), gd_madd_bit(3), gd_move(3), gd_open(3), gd_put_string(3), gd_reference(3), gd_rename(3), gd_rewrite_fragment(3).

25 December 2016 Version 0.10.0 GETDATA