32、Mastering Shell Scripting: Loops, User Input, and Practical Applications

Mastering Shell Scripting: Loops, User Input, and Practical Applications

1. Looping in Shell Scripts

Looping is a fundamental aspect of programming, and the Bash shell offers several commands for creating loops in scripts.

1.1 The if - then and continue Command

The if - then statement combined with the continue command can control the flow of loops. For example:

if [ $a -gt 2 ] && [ $a -lt 4 ]
then
    continue 2
fi

This code stops processing the commands inside the loop but continues the outer loop. In the script output, when $a is 3, the inner loop statements are skipped, and the outer loop continues.

1.2 Processing Lo