| Mon Jun  2 21:21:55 EST 2008  David Roundy <droundy@darcs.net>
|   * skip issue538.sh on windows, since I don't know how to run tests
|   since ./test.sh isn't accepted on windows.
|     hunk ./tests/issue538.sh 7
|     +if echo $OS | grep -i windows; then
|     +    echo I do not know how to run a test program under windows
|     +    exit 0
|     +fi
|     +

Since you already seem to be using unix commands (grep), perhaps you
could use stat(1) or find(1), both of which can examine the
executability (i.e. mode, on Unix) of files, e.g.

$ touch x y
$ chmod +x x
$ stat -c %a\ %A\ %n x y
755 -rwxr-xr-x x
644 -rw-r--r-- y
$ find -executable -type f
./x
$