gd_reference(3) 						      GETDATA							   gd_reference(3)

NAME

       gd_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
       reference 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 reference 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 descriptive error string for the last error encountered can be obtained  from
       a call to gd_error_string(3).

SEE ALSO

       gd_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)