NAME¶
gd_frameoffset — report the starting frame of fields in a dirfile
SYNOPSIS¶
#include <getdata.h>
off_t gd_frameoffset(DIRFILE *dirfile, int
fragment_index);
DESCRIPTION¶
The
gd_frameoffset() function queries a
dirfile(5) database specified by
dirfile and returns the frame offset (see
dirfile-format(5)) for the
fragment indexed by
fragment_index. The frame offset of a fragment
indicate the frame number of the first sample of data stored in binary files
associated with
RAW fields defined in the specified fragment. The frame
offset of a fragment containing no
RAW fields is ignored.
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_frameoffset() returns the frame offset of
the specified fragment. On error, it returns -1 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_BAD_INDEX
- The supplied index was out of range.
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¶
gd_alter_frameoffset(3),
gd_open(3),
gd_error(3),
gd_error_string(3),
dirfile(5),
dirfile-format(5)