get_nframes

Langue: en

Autres versions - même langue

Version: 8 December 2008 (fedora - 01/12/10)

Section: 3 (Bibliothèques de fonctions)

NAME

get_nframes --- report the size of a dirfile

SYNOPSIS

#include <getdata.h>
off_t get_nframes(DIRFILE *dirfile);

DESCRIPTION

The 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 calling get_error(3). A descriptive error string for the last error encountered can be obtained from a call to get_error_string(3).

SEE ALSO

dirfile(5), dirfile-encoding(5), dirfile_open(3), getdata(3), get_error(3), get_error_string(3)