gd_add_alias man page
gd_add_alias, gd_madd_alias — add a field to a Dirfile
int gd_add_alias(DIRFILE *dirfile, const char *alias_name, const char *target_code, int fragment_index);
int gd_madd_alias(DIRFILE *dirfile, const char *parent, const char *alias_name, const char *target_code);
The gd_add_alias() function adds the alias named alias_name pointing to target_code to the fragment indexed by fragment_index in the dirfile specified by dirfile. The gd_madd_alias() function behaves similarly, but adds the field as a meta-entry under the field indicated by the field code parent.
On success, gd_add_alias() and gd_madd_alias() return zero. On error, a negative-valued error code is returned. Possible error codes are:
The specified dirfile was opened read-only.
The library was unable to allocate memory.
Either the alias_name was invalid: containing an invalid character or lacking the containing fragment's namespace or affixes, or else the parent field code was not found, or was already a metafield.
The supplied dirfile was invalid.
The fragment_index specified was out of range.
The alias_name parameter duplicated that of an already existing entry.
The metadata of the fragment was protected from change. Or, the creation of a RAW field was attempted and the data of the fragment was protected.
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).
The functions gd_add_alias() and gd_madd_alias() appeared in GetData-0.8.0.
In GetData-0.10.0, the error return from these functions changed from -1 to a negative-valued error code.
gd_add(3), gd_alias_target(3), gd_entry(3), gd_madd(3), gd_metaflush(3), gd_open(3), dirfile-format(5)