Mac OS X Shell Scripting QuickStart

The Tutorial Shows You Step-by-Step How-to Getting-Started Making and Running a Bash Shell Script for Mac OS X 10.11 El Capitan BSD.

Shell Scripts are files in which we write a Sequence of Commands that we need to perform and are Executed using the Shell utility.

The Bash (Bourne Again Shell) is the Default Shell environment for some BSD/Unix system.

To Edit & Save our Bash Shell Script we’ll make Use of the Default Mac Shell Editor nano.

1. Open a Shell Terminal emulator window
   (Press “Enter” to Execute Commands)

   

2. Editing a Bash Script on Home Directory with nano
   First we Change to our Home with

   cd ~

   Then we Make the Bash Script with

   nano mybashscript.sh

   To be Runnable directly as a Shell Script we append a Bash Shebang to the Top like

   #!/bin/bash

   Then for Testing the Execution we should Insert a classic Hello-Word greating

   echo 'Hello World!'

   The ‘echo‘ Command simply Output a String on Terminal
   So finally our simple Bash Script will be containing just

   #!/bin/bash
   date
   echo 'Hello World!'
   echo 'From a Bash Shell Script :)'
   

   The Sequence of Bash Commands must be a Stack of sigle Commands

   myBashCommand1
   myBashCommand2
   ...
   

   Or simply in a Line of Commands Divided by a ‘;’ SemiColon

   myBashCommand1 ; myBashCommand2 ...

   Ctrl+x to Save & Exit from nano Editor

3. Executing the Hello-World Bash Script
   We Need to give the Execution Permissions with

   chmod +x ./mybashscript.sh

   Then to Run our little Bash Script simply

   ./mybashscript.sh

   You’ll be nicely greeted on Shell with something like

   Sun Jan 10 10:31:26 PST 2016
   Hello World!
   From a Bash Shell Script :)