gd_strings(3)

NAME
gd_strings — retrieve a list of string values from a dirfile

SYNOPSIS
#include <getdata.h>

const char **gd_strings(DIRFILE *dirfile);

DESCRIPTION
The gd_strings() function queries a dirfile(5) database specified by dirfile and returns a read-only list of values of the all STRING type fields defined in the database. Notably, this list does not include /META subfields.

The dirfile argument must point to a valid DIRFILE object previously created by a call to gd_open(3).

The array returned will be de-allocated by a call to gd_close(3) and should not be de-allocated by the caller. The list returned should not be assumed to be in any particular order, although it is guaranteed to be in the same order as the list of STRING fields returned by gd_field_list_by_type(3). The array is terminated by a NULL pointer. The number of strings in the array can be obtained from a call to gd_nfields_by_type(3).

The caller may not modify any strings in the array, or the array itself. Doing so may cause database corruption. The pointer returned is guaranteed to be valid until gd_strings() is called again with the same arguments, or until the array is de-allocated by a call to gd_close(3).

A corresponding list of names for these fields may be obtained by calling gd_field_list_by_type(3).

RETURN VALUE
Upon successful completion, gd_strings() returns a pointer to an array of strings containing the values of all the STRING fields defined in the dirfile database. The array is terminated by a NULL pointer. If no strings are defined in the database, an array consisting of only the NULL pointer is returned. On error it returns NULL and sets the dirfile error to a non-zero error value. Possible error values are:

GD_E_ALLOC
    The library was unable to allocate memory.

GD_E_BAD_DIRFILE
    The supplied dirfile was invalid.

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
dirfile(5), gd_open(3), gd_error(3), gd_error_string(3), gd_field_list_by_type(3), gd_mstrings(3), gd_nfields_by_type(3), gd_string(3)