Скачать или смотреть 2025 Linux Admin - Scripting and passing variables as arguments

In this video, I demonstrate how to use special variables and exit codes in Linux shell scripting. By writing and testing a simple script (variables.sh), I show how Bash handles script arguments, how to display them, and how to capture whether a command succeeds or fails. These are core scripting skills that every Linux administrator needs to know.


What You’ll Learn
How to write and execute a basic shell script.
How to make scripts executable with chmod u+x.
How $0, $1, $2 work for script name and positional arguments.
How $# shows the number of arguments passed.
How $* and $@ expand arguments differently.
How $? shows the exit status of the last command.
How errors (like missing files) affect exit codes.

Commands Demonstrated
vi – Create and edit scripts.
chmod u+x – Make a script executable.
./variables.sh – Run scripts with arguments.
echo $? – Check command success or failure.
cat – Trigger errors when files don’t exist (for testing exit codes).

Certifications This Helps With
This lesson supports scripting concepts tested in:
CompTIA Linux+
LPIC-1 (Linux Professional Institute Certification)
Red Hat Certified System Administrator (RHCSA)
Linux Foundation Certified System Administrator (LFCS)

Why Watch?
If you’re learning Linux scripting or preparing for certifications, this video will help you understand how arguments and exit codes work in Bash. These concepts form the foundation for writing reliable and flexible scripts.

[ec2-user@ip-172-31-19-169 ~]$ history
1 clear
2 ls
3 cat filecheck.sh
4 vi variables.sh
5 ls -ltrah
6 chmod u+x variables.sh
7 ls -ltrah
8 ./variables.sh
9 cat variables.sh
10 ./variables.sh Hello World From Hawaii
11 echo $?
12 ls
13 cat dog
14 echo $?
15 vi variables.sh
16 ./variables.sh Hello World From Hawaii
17 echo $?
18 ./variables.sh Hello World From Hawaii
19 vi variables.sh
20 ./variables.sh Hello World From Hawaii
21 echo $?
22 ls -ltrah
23 cat filecheck.sh
24 history
[ec2-user@ip-172-31-19-169 ~]$ cat variables.sh
#!/bin/bash
Written by JLS in Sept 2025

This is where I like to put variables
For this script, no varaibles needed

echo $0 $1 $2
echo $?

cat dog
echo $?

echo $#
echo $?

echo $*
echo $?

echo $@
echo $?

cat dog