gd_reference(3) GETDATA gd_reference(3)NAMEgd_reference — retrieve or set the reference field for a dirfile
SYNOPSIS
#include <getdata.h>
const char *gd_reference(DIRFILE *dirfile, const char *field_code);
DESCRIPTION
The gd_reference() function sets or retrieves the reference field (see
dirfile(5)) associated with the dirfile specified by dirfile. If the
field_code argument is non-NULL, the reference field for the dirfile
will be set to the field specified. If field_code is NULL, the refer‐
ence field is not modified. The field code should refer to a RAW
field, and may not contain a representation suffix.
RETURN VALUE
On success, gd_reference() returns the field code of the dirfile's ref‐
erence field, which will be field_code, if field_code is non-NULL. If
no RAW fields are defined in the dirfile, this function will return
NULL, without raising an error. On error, NULL is returned and the
dirfile error is set to a non-zero error value. Possible error values
are:
GD_E_ACCMODE
The specified dirfile was opened read-only.
GD_E_ALLOC
The library was unable to allocate memory.
GD_E_BAD_CODE
The field specified by field_code was not found.
GD_E_BAD_DIRFILE
The supplied dirfile was invalid.
GD_E_BAD_FIELD_TYPE
The field specified by field_code was not a RAW field.
GD_E_PROTECTED
The metadata of the primary format specification fragment (the
file named format in the root dirfile directory) was protected
from change.
The dirfile error may be retrieved by calling gd_error(3). A descrip‐
tive error string for the last error encountered can be obtained from a
call to gd_error_string(3).
SEE ALSOgd_metaflush(3), gd_open(3), gd_error(3), gd_error_string(3),
dirfile(5), dirfile-format(5)Version 0.7.0 20 July 2010 gd_reference(3)
