More Bash Basics: Commands, Conditions, And Math

Mark Wilkinson continues his Bash for the Powershell developer series:

An expression is a statement that evaluates to either true or false. In our case we are just checking if the $hour_of_day variable is less than 12 and greater than or equal to 5. When comparing numeric values you must use the same operators you are familiar with from PowerShell: -lt -gt -le -ge -ne. When comparing string values you have to use operators you might be more used to from other languages: == != and both values must be enclosed in double quotes [ "string1" == "string2" ].

With just the things Mark has shown so far, you can begin to build helpful scripts.

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