gd_delete(3)

NAME

gd_delete—remove an entry from a Dirfile

SYNOPSIS

#include <getdata.h>

int gd_delete(DIRFILE *dirfile, const char *field_code, unsigned int flags);

DESCRIPTION

The gd_delete() function attempts to delete the field or alias specified by field_code from the dirfile specified by dirfile. The field_code should not contain a representation suffix.

The flags argument influences how the deletion attempt occurs. It may be zero, for the default behaviour, or else one or more of the following flags, bitwise or'd together:

GD_DEL_DATA: If the field to be deleted is a RAW field, also delete the binary data file associated with it. If field_code specified a RAW field and this flag is not specified, the field will still be deleted but the binary file will be left untouched.
GD_DEL_DEREF: If the field to be deleted is a CONST or CARRAY field which is used as a parameter in the specification of other fields, resolve these other fields' dependence on the deleted field by replacing instances of field_code in their field specifications with the value of the scalar field.
GD_DEL_FORCE: Delete the indicated entry, even if it is used in the specification of other fields, either as a input for a derived vector field or as a scalar parameter in a field specification, or if it has aliases pointing to it.
GD_DEL_META: If the field to be deleted has metafields attached to it, attempt to delete those, too. If the field has metafields and this flag is not specified, the call will fail with the GD_E_DELETE error.

RETURN VALUE

On successful deletion, zero is returned. On error, a negative-valued error code is returned. Possible error codes 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 in the database.
GD_E_BAD_DIRFILE: The supplied dirfile was invalid.
GD_E_DELETE: The attempt to delete the field failed. Either it is used in the specification of other fields and GD_DEL_FORCE or GD_DEL_DEREF was not specified, or it has metafields and GD_DEL_META was not specified.
GD_E_INTERNAL_ERROR: An internal error occurred in the library while trying to perform the task. This indicates a bug in the library. Please report the incident to the GetData developers.
GD_E_IO: An error occurred while trying to close or delete the binary file associated with a RAW field.
GD_E_PROTECTED: The metadata of the fragment containing the field was protected from change. Or, the deletion of the binary data file associated with a RAW field was attempted and the data of the fragment was protected.
GD_E_UNKNOWN_ENCODING: The GD_DEL_DATA flag was given but the encoding scheme of the indicated format specification fragment is not known to the library. As a result, the library was unable to delete the binary file associated with a RAW field.
GD_E_UNSUPPORTED: The GD_DEL_DATA flag was given but the encoding scheme of the indicated format specification fragment does not support deleting the binary file associated with a RAW field.

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).

HISTORY

The function dirfile_delete() appeared in GetData-0.5.0.

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

In all GetData-0.8.x releases, passing an alias name to this function would delete the target of the alias. To delete an alias itself, a separate function, gd_delete_alias() was available.

In GetData-0.9.0, gd_delete_alias() was removed.