Chapter 5. Alternative Syntax
So far in the scripting journey, we have seen that we can use the test command to determine a conditional status. We have taken this a little further and discovered that we can also make use of the single square bracket. Here, we will recap the test command and look at the single square bracket in more detail. After having learned more about the square bracket, we will move onto more advanced variable or parameter management; thus, providing defaults and understating quoting issues.
Finally, we are going to see that within advanced shells like bash, korn, and zsh we can go with double brackets! Making use of the double round parenthesis and double square bracket can simplify the overall syntax and allow the standardization of the use of mathematical symbols.
In this chapter, we will cover the following topics:
- Test conditions
- Providing parameter defaults
- When in doubt – quote!
- Advanced tests using
[[ - Advanced tests using
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