If filename is a directory, isdir returns true. If it is not a directory, isdir returns false.

If filename does not exist, isdir generates an error.

See file for information on file names.

$\mathrm{isdir}\left(''/home/maple''\right)$

$\mathrm{true}$

$\mathrm{isdir}\left(''/home/maple/m/foo.m''\right)$

$\mathrm{false}$

$\mathrm{isdir}\left(''/home/maple/noexist''\right)$

Error, (in isdir) file or directory does not exist