daniel@stinkpad-02:~/misc_dump$ vi testy.sh
daniel@stinkpad-02:~/misc_dump$ cat testy.sh 
#!/bin/sh

echo 'it worked'
daniel@stinkpad-02:~/misc_dump$ chmod a+x testy.sh
daniel@stinkpad-02:~/misc_dump$ ./testy.sh 
it worked
daniel@stinkpad-02:~/misc_dump$ mv testy.sh testy
daniel@stinkpad-02:~/misc_dump$ ./testy
it worked
daniel@stinkpad-02:~/misc_dump$ vi testy
daniel@stinkpad-02:~/misc_dump$ cat testy
echo 'it worked'
daniel@stinkpad-02:~/misc_dump$ ./testy
it worked