Check whether directory is on current MATLAB path

ISONPATH checks if given directory is on the current MATLAB path. Vectorized in the sense that it accepts cell-arrays of strings.
y = ISONPATH(dirs) for string [dirs] checks whether the specified directory is on the MATLAB search path. The output [y] is a logical scalar equal to 'true' when the directory is on the path, 'false' otherwise.

In case [dirs] is a cell array of strings, the same check is performed for each entry in [dirs]. In this case, the output [y] is a logical array the same size as [dirs].

Note that a case-INsensitive comparison is used on windows platforms, while exact case match is required for Linux/Mac platforms.