Mastering Linux Shell Scripting - Second Edition

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 such as 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 ...