debian man page for gd_mcarrays

gd_mcarrays(3)							      GETDATA							    gd_mcarrays(3)

NAME
       gd_constants -- retrieve a list of CARRAY values from a dirfile

SYNOPSIS
       #include <getdata.h>

       const gd_carray_t *gd_mcarrays(DIRFILE *dirfile, const char *parent, gd_type_t return_type);

DESCRIPTION
       The  gd_mcarrays()  function  queries  a  dirfile(5) database specified by dirfile and returns a read-only list of values of the all CARRAY
       metafields for the supplied parent field, after type conversion to the data type specified by return_type.  For a list of valid symbols	to
       use for return_type, see the gd_get_carray(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, except that it is guaranteed to be in the same order as the list of CARRAY fields returned by
       gd_mfield_list_by_type(3).  The number of values in the array can be obtained from a call to gd_nmfields_by_type(3).

       The  caller may not modify any values in the array, nor the array itself.  Doing so may cause database corruption.  The pointer returned is
       guaranteed to be valid only until gd_mcarrays() is called again, 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_mcarrays() returns a pointer to an array of gd_carray_t objects containing the values of all the CARRAYs de-
       fined in the dirfile database.  The gd_carray_t is defined as:

	   typedef struct {
	     size_t	  n;		  /* array_len */
	     void	 *d;		  /* CARRAY data */
	   } gd_carray_t;

       where n specifies the length of the CARRAY data, and d is an array of the data values themselves.  The caller should cast the void  pointer
       to a type appropriate for the return_type specified.  The list is terminated by an end-of-list marker consisting of a gd_carray_t item with
       n set to zero.

       If no CARRAYs are defined in the database, a list containing only the end-of-list marker is returned.  On error, gd_mcarrays() 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_CODE
	       The supplied parent field code was not found, or referred to a metafield itself.

       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_carrays(3), gd_error(3), gd_error_string(3), gd_get_carray(3), gd_mfield_list_by_type(3), gd_nmfields_by_type(3), gd_open(3)

Version 0.7.0							  3 November 2010						    gd_mcarrays(3)