Commandline interface arguments processing
+Table of Contents
+1. Terminology
+1.1. Command and argument
++Every command-line application has a way of receiving input from +users, usually in the form of command-line arguments. A command-line +argument is a piece of information provided to the command-line +application when it's invoked. These arguments are provided as an +array of strings. The first element of the array (argument 0) is +typically the name of the command itself. +
+ ++In the example below, 'my-video-coder' is our command, and the rest +are arguments: +
+ +my-video-coder encode --input vid1.mp4 vid2.mp4 vid3.mp4 --quality 5 ++
+To better understand how these concepts work together, let's break +down our example command: +
+ +| argument # | +value(s) | +type | +
|---|---|---|
| 0 | +my-video-coder | +command | +
| 1 | +encode | +subcommand | +
| 2 | +–input | +option1 | +
| 3, 4, 5 | +vid1.mp4 vid2.mp4 vid3.mp4 | +parameters for –input option | +
| 6 | +–quality | +option2 | +
| 7 | +5 | +parameter for –quaily option | +
1.2. Subcommand
++Subcommands are arguments that invoke more specific action that a +command can perform. They are often used with commands that have +multiple functions. In our example, encode is a subcommand of +my-video-coder. +
+1.3. Option
++Options are arguments that change the behavior of a command or +subcommand. They usually start with a dash (-) or double dash +(–). For instance, –input and –quality are options in our +example command. +
+1.4. Parameter
++Parameter provides additional information to a command, subcommand or +option. +
+ ++For instance, in our example: +
+-
+
- 'vid1.mp4 vid2.mp4 vid3.mp4' are parameters for the –input option. +
- '5' is a parameter for the –quality option. +