The Basics Of Bash: Writing Data

Mark Wilkinson hits us with some basic Bash output management:

If you have experience with PowerShell, some properties of Bash variables will feel familiar. In Bash, variables are denoted with a $ just like in PowerShell, but unlike PowerShell the $ is only needed when they are being referenced. When you are assigning a value to a variable, the $ is left off:

#!/bin/bashset -eset -umy_var="World"printf "Hello ${my_var}\n"

Above we assigned a value to my_var without using the $, but when we then referenced it in the printf statement, we had to use a $. We also enclosed the variable name in curly braces. This is not required in all cases, but it is a good idea to get in the habit of using them. In cases where you are using positional parameters above 9 (we’ll talk about this later) or you are using a variable in the middle of a string the braces are required, but there is no harm in adding them every time you use a variable in a string.

The basic syntax is pretty familiar to most programming languages, and there’s nothing scary about outputs, even when Mark starts getting into streams.

Related Posts

The Decorator Pattern

Nancy Jain explains the Decorator pattern: Decorator design pattern is a structural design pattern. Structural design patterns focus on Class and Object composition and decorator design pattern is about adding responsibilities to objects dynamically. Decorator design pattern gives some additional responsibility to our base class. This pattern is about creating a decorator class that can […]

Read More

Why .NET And Java Have StringBuilders

Randolph West walks us through a performance troubleshooting issue with a twist: So we branch the the code in source control, and start writing a helper class to manage the data for us closer to the application. We throw in a SqlDataAdapter, use the Fill() method to bring back all the rows from the query in one go, and then […]

Read More

Categories

February 2018
MTWTFSS
« Jan Mar »
 1234
567891011
12131415161718
19202122232425
262728