1get_nframes(3)                      GETDATA                     get_nframes(3)
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NAME

6       get_nframes — report the size of a dirfile
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SYNOPSIS

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

14       The  get_nframes()  function queries a dirfile(5) database specified by
15       dirfile and returns the number of frames in the database.   Since  dif‐
16       ferent  fields  may  have differing number of frames, the Dirfile Stan‐
17       dards (see dirfile(5)) dictate that the number of frames in  the  data‐
18       base  is  defined  to be equal to the number of frames in the first raw
19       field specified in the format file.
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21       If no vector fields are defined in the database, get_nframes()  returns
22       zero and succeeds.
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24       The  dirfile  argument  must point to a valid DIRFILE object previously
25       created by a call to dirfile_open(3).
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RETURN VALUE

29       Upon successful completion, get_nframes() returns the number of  frames
30       in  the  dirfile.  On error, it returns zero and sets the dirfile error
31       to a non-zero error value.  Possible error values are:
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33       GD_E_BAD_DIRFILE
34               The supplied dirfile was invalid.
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36       GD_E_RAW_IO
37               An attempt to stat(2) the file associated with first raw  field
38               defined in the format failed.
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40       GD_E_UNSUPPORTED
41               Reading from dirfiles with the encoding scheme of the specified
42               dirfile is not supported by the  library.   See  dirfile-encod‐
43               ing(5) for details on dirfile encoding schemes.
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45       The dirfile error may be retrieved by calling get_error(3).  A descrip‐
46       tive error string for the last error encountered can be obtained from a
47       call to get_error_string(3).
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SEE ALSO

50       dirfile(5),  dirfile-encoding(5),  dirfile_open(3), getdata(3), get_er‐
51       ror(3), get_error_string(3)
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55Version 0.5.0                   8 December 2008                 get_nframes(3)
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