Creating your first shell script

In this section, we will take a look at creating your first shell script.

To Create a shell script name create-and-launch-script.sh

$ vi create-and-launch-script.sh

Run script as command

Whenever a command is run at a linux system, the O.S looks at the path configured in the $PATH environment variable to locate the executable or script for the command.
If it cannot find the command in the $PATH then a command not found error will be thrown.
To add our script as a command, append the path to the directory containing the script to the end of the $PATH variable.
```
$ export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/home/michael
```
A better way to do this is to append the path to the directory to $PATH variable
```
$ export PATH=$PATH:/home/michael
```
Run the command
```
$ create-and-launch-script
```
To see the location of the command
```
$ which create-and-launch-script
```

For a shell script to work, we must set the correct permissions to the file, if the permissions are not set a "Permission Denied" error will be thrown when you run the script for the first time.

Inspect the file permissions

$ ls -l /home/michael/create-and-launch-script

Add executable permissions to a file and then inspect the file to check if it got write permissions.
```
$ chmod +x /home/michael/create-and-launch-script
$ ls -l /home/michael/create-and-launch-script
```

Now, run the script

$ /home/michael/create-and-launch-script