c/io/ftell

Returns the file position indicator for the file stream.

If the stream is open in binary mode, the value obtained by this function is the number of bytes from the beginning of the file.

If the stream is open in text mode, the value returned by this function is unspecified and is only meaningful as the input to fseek.

Return value
File position indicator on success or if failure occurs.

On error, the variable is set to implementation-defined positive value.