Arguments passed to a script are processed in the same order in which they’re sent. The indexing of the arguments starts at one, and the first argument can be accessed inside the script using $1. Similarly, the second argument can be accessed using $2, and so on. The positional parameter refers to this representation of the arguments using their position. //

Using flags is a common way of passing input to a script. When passing input to the script, there’s a flag (usually a single letter) starting with a hyphen (-) before each argument.

Let’s take a look at the userReg-flags.sh script, which takes three arguments: username (-u), age (-a), and full name (-f).

We’ll modify the earlier script to use flags instead of relying on positional parameters. The getopts function reads the flags in the input, and OPTARG refers to the corresponding values: