- 01Setting up (what you'll need)
- 02Your first shell script (echo)
- 03Using variables
- 04Command-line arguments ($1, $2 ...)
- 05Branching (the if statement)
- 06Repeating (the for loop)
- 07Repeating (the while loop)
- 08Writing your own function
- 09Working with arrays
- 10Command substitution ($())
- 11Working with strings (parameter expansion)
- 12Reading from standard input (read)
- 13Exit status and && / ||
- 14Pipes and redirection
- 15The case statement
- 16Arithmetic ($(( )))
- 17The basics of grep, sed and awk
- 18Argument checks and error handling
- 19Function return values and exit codes
- 20[Project] Build a small log-tallying script
[Project] Build a small log-tallying script
In this lesson you combine the arrays, functions, grep, and arithmetic covered so far into a simple log-tallying script. It is the capstone of this shell scripting introduction.
Operations teams write scripts like this constantly: total the entries at each log level (INFO, WARN, ERROR) and raise an alert when there are too many problems.
The sample code sets up an array of log levels, counts each one with grep -c, and prints the results as a report.
Variables, arrays, branching, and text-processing commands — everything covered in these lessons — are the foundations of real server operations and automation work. Starting with small scripts and gradually taking on more complex automation is the shortest path to using shell scripting professionally.
๐งช This site can't compile or run Shell Script directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser โ nothing is sent anywhere).