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.

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

SEE ALSO¶

gd_close(3), gd_error(3), gd_error_string(3), gd_metaflush(3), gd_open(3)