gd_eof(3)							      GETDATA								 gd_eof(3)

NAME

       gd_eof -- report the number of samples in a dirfile field

SYNOPSIS

       #include <getdata.h>

       off_t gd_eof(DIRFILE *dirfile, const char *field_code);

DESCRIPTION

       The  gd_eof()  function queries a dirfile(5) database specified by dirfile and returns the sample number of the end-of-field marker for the
       vector field given by field_code.  This is effectively the total number of samples available for the field, including any frame offset.

       The caller should not assume that this is equivalent (when accounting for the samples-per-frame of the indicated field) to  the	number	of
       frames in the database returned by gd_nframes(3), nor even that the end-of-field marker falls on a frame boundary.

       For  a  RAW  field,  the end-of-field marker occurs immediately after the last datum in the data file associated with the field.  For other
       field types, the end-of-field marker is equivalent to the end-of-field marker closest to the start of the dirfile of any of the	field  in-
       puts.  The special field INDEX has no end-of-field marker.

       The  end-of-field  marker  for  a  field  containing  no  data  is  in  the same location as, or before, its beginning-of-field marker (see
       gd_bof(3)).  For a RAW field, the difference between the locations of the beginning- and end-of-field markers indicates the number of  sam-
       ples of data actually stored on disk.

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

RETURN VALUE

       Upon successful completion, gd_eof() returns the sample number of the end-of-field marker for the indicated field.  On error, it returns -1
       and sets the dirfile error to a non-zero error value.  Possible error values are:

       GD_E_BAD_CODE
	       The field specified by field_code or one of the fields it uses as input was not found in the database.

       GD_E_BAD_DIRFILE
	       The supplied dirfile was invalid.

       GD_E_BAD_FIELD_TYPE
	       The location of the non-existent end-of-field marker for the special field INDEX was requested, possibly as a result of	the  field
	       specified by field_code using INDEX as one of its inputs.

       GD_E_BAD_REPR
	       The representation suffix specified in field_code, or in one of its inputs was not recognised.

       GD_E_DIMENSION
	       A scalar field was found where a vector field was expected in the definition of field_code or one of its inputs, or else field_code
	       itself specified a scalar field.

       GD_E_RAW_IO
	       An attempt to stat(2) the file associated with the field, or one of its input fields, failed.

       GD_E_RECURSE_LEVEL
	       Too many levels of recursion were encountered while trying to resolve field_code.  This usually indicates a circular dependency	in
	       field specification in the dirfile.

       GD_E_UNKNOWN_ENCODING
	       The size of the decoded data file associated with the specified field or one of its inputs could not be determined, because its en-
	       coding scheme was not understood.

       GD_E_UNSUPPORTED
	       The size of the decoded data file associated with the specified field or one of its inputs could not be determined, because its en-
	       coding scheme was not supported.

       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), dirfile-encoding(5), gd_open(3), gd_bof(3), gd_error(3), gd_error_string(3), gd_nframes(3)

Version 0.7.0							  15 October 2010							 gd_eof(3)