gd_rewrite_fragment(3)

NAME

gd_rewrite_fragment—re-write a Dirfile format specification fragment

SYNOPSIS

#include <getdata.h>

int gd_rewrite_fragment(DIRFILE *dirfile, int fragment);

DESCRIPTION

The gd_rewrite_fragment() writes the format specification fragment specified by fragment to disk, regardless of whether it has changed or not, overwriting the existing file.

In addition to being simply a valid fragment index, fragment may also be the special value GD_ALL_FRAGMENTS, which indicates that all fragments should be rewritten.

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.

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_BAD_INDEX: The supplied fragment index was out of range.
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 2³¹ 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).

BUGS

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 gd_rewrite_fragment() function appeared in GetData-0.7.0.

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