The CountBytes(file) command counts the number of bytes from file's current position to the end of the file.

An error is raised if file is not a valid descriptor or if the filename does not exist.

$\mathrm{FileTools}\left[\mathrm{Binary}\right]\left[\mathrm{Write}\right]\left(''foo''\,\mathrm{integer}\left[1\right]\,\left[1\,2\,3\,4\,5\,6\,7\,8\,9\,0\right]\right)\:$

$\mathrm{FileTools}\left[\mathrm{Binary}\right]\left[\mathrm{Close}\right]\left(''foo''\right)\:$

$\mathrm{FileTools}\left[\mathrm{Binary}\right]\left[\mathrm{CountBytes}\right]\left(''foo''\right)$

$10$

$\mathrm{FileTools}\left[\mathrm{Position}\right]\left(''foo''\,4\right)\:$

$\mathrm{FileTools}\left[\mathrm{Binary}\right]\left[\mathrm{CountBytes}\right]\left(''foo''\right)$

$6$

$\mathrm{FileTools}\left[\mathrm{Remove}\right]\left(''foo''\right)\:$