today@v4:~$ vi HelloWorld.sh
HelloWorld.sh
#!/bin/bash
echotext="Hello World!"
echo "$echotext"
today@v4:~$ ls
HelloWorld.sh
today@v4:~$ ls -l
---------- 1 today staff 3 Jul 8 18:54 HelloWorld.sh
today@v4:~$ ./HelloWorld.sh
-bash: ./HelloWorld.sh: Permission denied
today@v4:~$ chmod 777 HelloWorld.sh
today@v4:~$ ./HelloWorld.sh
Hello World!
today@v4:~$ ./HelloWorld.sh
Hello World!
today@v4:~$ ./HelloWorld.sh
Hello World!
today@v4:~$ ls -l HelloWorld.sh
-rwxrwxrwx 1 today staff 3 Jul 8 18:55 HelloWorld.sh
today@v4:~$ rm HelloWorld.sh
today@v4:~$ whoami
today
today@v4:~$ exit