get_nframes (3) Linux Manual Page
NAME
get_nframes — report the size of a dirfile
SYNOPSIS
#include <getdata.h>
-
off_t get_nframes(DIRFILE *dirfile);
DESCRIPTION
get_nframes() function queries a dirfile(5) database specified by dirfile and returns the number of frames in the database. Since different fields may have differing number of frames, the Dirfile Standards (see dirfile(5)) dictate that the number of frames in the database is defined to be equal to the number of frames in the first raw field specified in the format file.
If no vector fields are defined in the database, get_nframes() returns zero and succeeds.
The dirfile argument must point to a valid DIRFILE object previously created by a call to dirfile_open(3).
RETURN VALUE
Upon successful completion, get_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_BAD_DIRFILE- The supplied dirfile was invalid.
GD_E_RAW_IO- An attempt to
stat(2) the file associated with first raw field defined in the format failed. GD_E_UNSUPPORTED- Reading from dirfiles with the encoding scheme of the specified dirfile is not supported by the library. See
dirfile-encoding(5) for details on dirfile encoding schemes. The dirfile error may be retrieved by callingget_error(3). A descriptive error string for the last error encountered can be obtained from a call toget_error_string(3).
SEE ALSO
dirfile(5), dirfile-encoding(5), dirfile_open(3), getdata(3), get_error(3), get_error_string(3)