embedding commands

Command substitution is one of the vital features that you can leverage within shell scripting to make your scripts more dynamic and functional. It allows the output of a shell command to be captured and substituted in another command, or used as a value in a variable. This feature is incredibly useful in programming situations where the output from one command is dependent on the output of another. In the world of shell scripting, especially in Unix-like operating systems, command substitution is a mechanism by which the shell executes a command and replaces the command itself with the output. This output then can be used as input or arguments to another command.