- int gd_verbose_prefix(DIRFILE *dirfile, const char *prefix);
GetData only prints error messages for a given Dirfile if opened along with the GD_VERBOSE flag, or if the flag has been subsequently set on the dirfile using gd_flags(3). If this flag is not set, this function still updates the prefix, but GetData does not use it.
If GD_VERBOSE is set, when the library encounters an error, it prints the supplied prefix (if any), followed immediately by the error message (which is the message returned by gd_error_string(3)), followed by a newline. All output goes to the standard error I/O stream (stderr(3)) of the caller.
The dirfile argument must point to a valid DIRFILE object previously created by a call to gd_open(3).
RETURN VALUEUpon successful completion, gd_verbose_prefix() returns the zero. On error, it returns -1 and sets the dirfile error to a non-zero error value. Possible error values are:
- The library was unable to allocate memory.
- The supplied dirfile was invalid.