trusty (3) gd_constants.3.gz

NAME

       gd_constants — retrieve a list of constant values from a dirfile

SYNOPSIS

       #include <getdata.h>

       const void *gd_constants(DIRFILE *dirfile, gd_type_t return_type);

DESCRIPTION

       The  gd_constants()  function  queries a dirfile(5) database specified by dirfile and returns a read-only
       list of values of the all CONST type fields defined in the database after type  conversion  to  the  data
       type specified by return_type.  Notably, this list does not include /META subfields.  For a list of valid
       symbols to use for return_type, see the gd_get_constant(3) man page.

       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 CONST fields returned by gd_field_list_by_type(3).  The  array  is
       unterminated.  The number of values in the array can be obtained from a call to gd_nfields_by_type(3).

       The  caller  may  not  modify  any values in the array, or the array itself.  Doing so may cause database
       corruption.  The pointer returned is guaranteed to be valid only until  gd_constants()  is  called  again
       with the same arguments, or until the dirfile's metadata is modified (by adding, modifying or deleting an
       entry), 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_constants() returns a pointer to an array of values containing the  values
       of  all the constants defined in the dirfile database.  If no constants are defined in the database, NULL
       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.

       GD_E_BAD_TYPE
               The return_type specified 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_get_constant(3),
       gd_nfields_by_type(3)