gistfile1.txt

# make tags
$ ./setup
$ ls
$ mkdir {a,b,c}
$ mkdir unexisting/path
mkdir: cannot create directory `unexisting/path': No such file or directory
$ ls
a  b  c
$ touch file-in-root
$ touch a/fa
$ touch a/b/fab
$ touch c/b/fbc
$ ls
a b c file-in-root
$ ls a
b fa
$ ls a/b
fab
$ ls b/a
fab
$ ./teardown

# read and write
$ ./setup
$ echo 'content' >wr
$ cat wr
content
$ ./teardown

# copy and move 
$ ./setup
$ touch cm
$ mv cm ..
$ ls
$ cp ../cm .
$ ls
cm
$ mv ../cm mc
cm mc
$ ./teardown