xenial (3) gd_tell.3.gz

NAME

       gd_tell — reposition a dirfile field pointer

SYNOPSIS

       #include <getdata.h>

       off_t gd_tell(DIRFILE *dirfile, const char *field_code);

DESCRIPTION

       The  gd_tell()  function  reports  the current position of the I/O pointer of the field field_code in the
       dirfile(5) database specified by dirfile.

       Only RAW fields (and the implicit INDEX  field)  have  field  pointers  associated  with  them.   Calling
       gd_tell() on a derived field will report the position of the I/O pointer of the derived field only if all
       of it's inputs are positioned the same.  Otherwise, an error results.

RETURN VALUE

       Upon successful completion, gd_tell() returns the I/O position of the specified  field  in  samples.   On
       error, it returns -1 and set the dirfile error to a non-zero value.  Possible error values are:

       GD_E_ALLOC
               The library was unable to allocate memory.

       GD_E_BAD_CODE
               The  field  specified by field_code, or one of the fields it uses for input, was not found in the
               database.

       GD_E_BAD_DIRFILE
               The supplied dirfile was invalid.

       GD_E_DIMENSION
               The specified field or one of its inputs wasn't of vector type.

       GD_E_DOMAIN
               The I/O position of a derived field wasn't well defined because its input  fields  simultaneously
               read from different places in the same RAW field.

       GD_E_INTERNAL_ERROR
               An internal error occurred in the library while trying to perform the task.  This indicates a bug
               in the library.  Please report the incident to the maintainer.

       GD_E_IO An error occurred while trying to open or read from a file on disk containing a raw field.

       GD_E_RECURSE_LEVEL
               Too many levels of recursion were encountered while trying to resolve field_code.   This  usually
               indicates a circular dependency in field specification in the dirfile.

       GD_E_UNKNOWN_ENCODING
               The  encoding  scheme  of  a  RAW field could not be determined.  This may also indicate that the
               binary file associated with the RAW field could not be found.

       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 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_open(3), gd_getdata(3), gd_putdata(3), gd_seek(3).