Naming variables

Working of Bash variables

When you write a bash script, you either want to manipulate the already defined variable, set the value of the variable, or simply read the predefined variables. There are various ways to set values of a variable:...

Naming variables

There are a few rules to keep in mind while naming a variable:...

Using Local and global variables in bash

When you define a variable in your shell, it is only accessible during that particular session. Because that is a local variable. In the below example you can see that when we tried to access the variable “var1” in the new session (session number-1692), it does not print our variable value....

Types of bash variables

There are two types of variables in bash:...

Built-in special variables

Bash comes with some built-in special variables. These variables store some important data that can come in handy when you write a shell script. They are available for use to all users. Below is the list of these special variables and the result they store:...

Using array variables in Bash

Arrays are used to store data and in bash, you can store values of different types or the same type in an array....

Explicitly declaring datatype of a variable

In bash, we do not need to declare data types, like any other programming languages (int, str, etc..). The data type is identified by the shell script/shell itself (the variables defined in bash are termed as untyped). But there can be some circumstances when you will want to explicitly define the data type. In such cases, you can utilize the declare command to create a variable with a particular data type. Declare commands offer many flags to explicitly declare data types. Below is the list of those flags:...

Command-line arguments

Command-line arguments or positional parameters are used to pass input to a shell script or a command. Using command-line arguments makes the script more dynamic....

Command substitution

Sometimes, while writing a shell script you will encounter some instances when you want to assign the output of a particular command to a variable. This can be done with the help of command substitution.  Command substitution typically works by running a particular shell command and storing its result in a variable for further use or to display....