gd_get_carray_slice(3)						      GETDATA						    gd_get_carray_slice(3)

NAME

       gd_get_carray, gd_get_carray_slice -- retrieve CARRAY data from a dirfile database

SYNOPSIS

       #include <getdata.h>

       int gd_get_carray_slice(DIRFILE *dirfile, const char *field_code, unsigned int start, size_t len, gd_type_t return_type, void *data_out);

       int gd_get_carray(DIRFILE *dirfile, const char *field_code, gd_type_t return_type, void *data_out);

DESCRIPTION

       The  gd_get_carray_slice()  function  queries  a dirfile(5) database specified by dirfile for the CARRAY scalar array field_code, which may
       contain a representation suffix.  The data in the field is converted to the data type specified by return_type, and stored in the user-sup-
       plied  buffer  data_out.   The first element of the field stored is given by start, and the number of elements stored is given by len.  The
       gd_get_carray() function behaves similarly, except it returns the entire field.

       The dirfile argument must point to a valid DIRFILE object previously created by a call to gd_open(3).  The argument data_out must point	to
       a valid memory location of sufficient size to hold all the requested data of the return type specified.	The number of elements returned by
       gd_get_carray() may be obtained by calling gd_carray_len(3).  Unlike gd_getdata(3), calling gd_get_carray_slice() never results in a  short
       read; attempting to read past the end of the CARRAY will result in an error, and no data will be returned.

       The return_type argument should be one of the following symbols, which indicates the desired return type of the data:

	      GD_UINT8	 unsigned 8-bit integer

	      GD_INT8	 signed (two's complement) 8-bit integer

	      GD_UINT16  unsigned 16-bit integer

	      GD_INT16	 signed (two's complement) 16-bit integer

	      GD_UINT32  unsigned 32-bit integer

	      GD_INT32	 signed (two's complement) 32-bit integer

	      GD_UINT64  unsigned 64-bit integer

	      GD_INT64	 signed (two's complement) 64-bit integer

	      GD_FLOAT32 IEEE-754 standard 32-bit single precision floating point number

	      GD_FLOAT64 IEEE-754 standard 64-bit double precision floating point number

	      GD_COMPLEX64
			 C99-conformant 64-bit single precision complex number

	      GD_COMPLEX128
			 C99-conformant 128-bit double precision complex number

	      GD_NULL	 the  null  type: the database is queried as usual, but no data is returned.  In this case, data_out is ignored and may be
			 NULL.

       The return type of the field need not be the same as the type of the data stored in the database.  Type conversion  will  be  performed	as
       necessary  to  return  the  requested type.  If the field_code does not indicate a representation, but conversion from a complex value to a
       purely real one is required, only the real portion of the requested vector will be returned.

RETURN VALUE

       On success, gd_get_carray() and gd_get_carray_slice() return zero.  On error, they return -1 and set the dirfile error to a non-zero value.
       Possible error values are:

       GD_E_BAD_CODE
	       The field specified by field_code was not found in the database.

       GD_E_BAD_DIRFILE
	       An invalid dirfile was supplied.

       GD_E_BAD_FIELD_TYPE
	       The  supplied field_code referred to a field of a type other than CARRAY.  The caller should use gd_getdata(3), gd_get_constant(3),
	       or gd_get_string(3) instead.

       GD_E_BAD_REPR
	       The representation suffix specified in field_code, or in one of the field codes it uses for input, was invalid.

       GD_E_BAD_TYPE
	       An invalid return_type was specified.

       GE_E_BOUNDS
	       A request for data beyond the end of the field was made.

       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 maintainer.

       The  dirfile error may be retrieved by calling gd_error(3).  A descriptive error string for the last error encountered may be obtained from
       a call to gd_error_string(3).

SEE ALSO

       dirfile(5), gd_carray_len(3), gd_carrays(3), gd_error(3), gd_error_string(3), gd_get_constant(3), gd_open(3), gd_put_carray_slice(3)

Version 0.7.0							  3 Novmeber 2010					    gd_get_carray_slice(3)