Command Substitution
Explore command substitution to use the output of one command directly as the input or argument of another. Learn to save output to variables, build efficient command pipelines, and streamline process management through practical examples and exercises.
We'll cover the following...
Example of command substitution
We can use the output of one command when invoking another command. This is handy when a program’s argument needs to be generated from another program’s output. We can do this with a feature called command substitution. We’ve already seen variable expansion with curly braces, like ${variable}, where the variable’s value is expanded. Command substitution works similarly. With command substitution, the output of the command replaces the command itself. To define a command substitution, we put the command in parentheses instead of curly braces.
We saw an example of command substitution in Building Your Prompt when we used the tput command to ...