gd_nframes(3) GETDATA gd_nframes(3)NAMEgd_nframes — report the size of a dirfile
SYNOPSIS
#include <getdata.h>
off_t gd_nframes(DIRFILE *dirfile);
DESCRIPTION
The gd_nframes() function queries a dirfile(5) database specified by
dirfile and returns the number of frames in the database. Since dif‐
ferent fields may have differing number of frames, the Dirfile Stan‐
dards (see dirfile(5)) dictate that the number of frames in the data‐
base is defined to be equal to the number of frames in the reference
field defined by the /REFERENCE directive (see dirfile-format(5)) or,
if no such reference field is defined, by the first raw field specified
in the format specification.
If no vector fields are defined in the database, gd_nframes() returns
zero and succeeds.
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_nframes() returns the number of frames
in the dirfile. On error, it returns zero 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_RAW_IO
An attempt to determine the (unencoded) size of the data file
associated with the reference field failed.
GD_E_UNKNOWN_ENCODING
The size of the decoded data file associated with the reference
field could not be not be determined because its encoding was
not understood.
GD_E_UNSUPPORTED
The size of the decoded data file associated with the reference
field could not be not be determined because its encoding was
not supported.
The dirfile error may be retrieved by calling gd_error(3). A descrip‐
tive error string for the last error encountered can be obtained from a
call to gd_error_string(3).
SEE ALSOdirfile(5), dirfile-encoding(5), gd_open(3), gd_bof(3), gd_eof(3),
gd_error(3), gd_error_string(3)Version 0.8.0 19 August 2011 gd_nframes(3)
