Ruby Command Line Arguments

You re not just a rubyist you re a software developer right.

Ruby command line arguments. The rails command lineafter reading this guide you will know. How to experiment with objects through an interactive shell. To work with the actual values of the arguments that are passed into your ruby program just treat argv as a normal ruby array and get the values like this. Optionparser has a number of features that make it quite appealing to ruby programmers.

How to create a rails application. How to generate models controllers database migrations and unit tests. How to use command line arguments. In your ruby programs you can access any command line arguments passed by the shell with the argv special variable argv is an array variable which holds as strings each argument passed by the shell.

Ruby is generally run from the command line in the following way ruby options programfile arguments. Using command line arguments adds a new tool to your ruby toolbelt which you can use to get user input into your program if you choose. Ruby command line argv check length rb one too few arguments ruby command line argv check length rb one two working on one two values received on the command line are strings in this snippet of code we first check if we got exactly 2 parameters and we do we add them together. Ruby comes equipped with a powerful and flexible tool to parse command line options optionparser.

Once you learn how to use this you ll never go back to looking through argv manually. Our input file should be the first command line arg input file argv 0 our output file should be the second command line arg. When written inside your ruby program argv will take take a command line command that looks like this. Ruby captures command line arguments with a special array named argv.

Using command line arguments. How to start a development server. The environment command lets you query rubygems for its configuration for use in shell scripts or as a debugging aid. The rubygems environment can be controlled through command line arguments gemrc files environment variables and built in defaults.