The IsOpen(file) command searches the internal file table to determine if file refers to an open file.

$\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{Open}\right]\left(\mathrm{testfile}\right)\:$

$\mathrm{FileTools}\left[\mathrm{IsOpen}\right]\left(\mathrm{testfile}\right)$

$\mathrm{true}$

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

$\mathrm{FileTools}\left[\mathrm{IsOpen}\right]\left(\mathrm{testfile}\right)$

$\mathrm{false}$