Description: Substituting in the context of shell scripting refers to the process of replacing a variable or command with its corresponding value or output. This mechanism is fundamental in script programming and command-line interaction, as it allows users to manipulate and manage data efficiently. Substitution is commonly performed using the dollar sign ($) followed by the variable name, which allows access to its content. Additionally, it includes command substitution, where the output of one command can be used as input for another. This process is essential for task automation and the creation of complex scripts, facilitating interaction between different commands and variables in the terminal environment. The ability to effectively substitute variables and commands is one of the features that makes shells powerful tools for developers and system administrators.
