This article will explain what the $@ is in Bash and Bash/Shell scripting and how and why you might use it. The $@ variable is a special variable in Bash which holds the value of all of the command line arguments/parameters passed to the script. Command Line Arguments/Parameters in Bash Using command-line arguments/parameters in shell scripts is an important and useful feature, so we have a full article on it: This article follows on from our article on Command Line Arguments in Shell/Bash Scripts $@ Contains All Parameters/Arguments Passed to … Read more

The diff command is an easy way to compare files or directories from the Linux shell. This article will show you how to use it, with some examples of common usage. The diff command performs a line-by-line comparison of two files or directories and outputs the differences between them. Why would you want to compare files or directories? You might have two files with the same name that look similar and want to see the difference between them. Comparing changes to the programming code in a project you’re … Read more

The cat (concatenate) command in Linux/Bash is most commonly used to read the contents of a file. It outputs the contents of a given file. Here’s how to use it. cat concatenates files to standard output – by default, this is to the console for viewing on your computer screen. This makes it useful for quickly viewing the contents of files. It also has other uses, but first, the syntax: cat Syntax cat [OPTIONS] [FILE] Note that: If FILE is not specified, will read from standard input (stdin) Multiple FILEs can be specified, separated by … Read more