# Questions about OptionParser
**URL:** https://forum.crystal-lang.org/t/questions-about-optionparser/3569
**Category:** Help & Support
**Created:** [July 29, 2021, 10:14am UTC](https://forum.crystal-lang.org/t/questions-about-optionparser/3569 "2021-07-29T10:14:08Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Fulgurance](https://forum.crystal-lang.org/u/Fulgurance)
#### Post date: [July 29, 2021, 10:14am UTC](https://forum.crystal-lang.org/t/questions-about-optionparser/3569/1 "2021-07-29T10:14:08Z")
Hello, actually I’m programmin a package manager for my Linux Distribution with crystal.
I have some questions about OptionParser. Are there anyway to catch option but without any “–” or “-” ? This is very annoying because a lot of command line interface don’t use that. For example the command “apt install” don’t use “apt --install”.
One other question is, I seen you have an option parser.banner. Very good idea honestly ! But my question is: how I can specify with “OptionParser.parse do |parser|” when the user input nothing ? I didn’t see any method for that.
---
### Author:  [@aravindavk](https://forum.crystal-lang.org/u/aravindavk)
#### Post date: [July 29, 2021, 10:48am UTC](https://forum.crystal-lang.org/t/questions-about-optionparser/3569/2 "2021-07-29T10:48:28Z")
Check the example about Subcommands [here](https://crystal-lang.org/api/1.1.1/OptionParser.html#subcommands)
Adding an example specific to your usecase(`apt.cr`)
```auto
require "option_parser"
install = false
install_yes = false
pos_args = [] of String
parser = OptionParser.new do |parser|
parser.banner = "Usage: apt [subcommand] [arguments]"
parser.on("install", "Install packages") do
install = true
parser.banner = "Usage: apt install [arguments]"
parser.on("-y", "--yes", "No Prompt") { install_auto = true }
end
parser.unknown_args do |args|
pos_args = args
end
parser.invalid_option do |flag|
STDERR.puts "Invalid Option: #{flag}"
exit 1
end
parser.missing_option do |flag|
STDERR.puts "Missing Option: #{flag}"
exit 1
end
end
parser.parse
if install
if pos_args.size == 0
STDERR.puts "No packages specified for install"
exit 1
end
puts "Installing #{pos_args.join(", ")}"
else
puts parser
exit 1
end
```
```auto
crystal build apt.cr
./apt install abcd efgh
```
---
### Author:  [@Fulgurance](https://forum.crystal-lang.org/u/Fulgurance)
#### Post date: [July 29, 2021, 7:33pm UTC](https://forum.crystal-lang.org/t/questions-about-optionparser/3569/3 "2021-07-29T19:33:58Z")
Thanks you very much for you reply ! One other question. I had a problem when I tried to use the parser and when I use colourised string ( with colorize).
How can I colour the output without problem ? I mean after the parser do his job, how for example can I colour the banner ?
---
### Author:  [@Blacksmoke16](https://forum.crystal-lang.org/u/Blacksmoke16)
#### Post date: [July 29, 2021, 8:12pm UTC](https://forum.crystal-lang.org/t/questions-about-optionparser/3569/4 "2021-07-29T20:12:50Z")
There are also some shards that make building CLIs a bit easier if you need more robust functionality: [GitHub - veelenga/awesome-crystal: A collection of awesome Crystal libraries, tools, frameworks and software](https://github.com/veelenga/awesome-crystal#cli-builders).
if you’re feeling adventurous, Athena’s Console component is also usable atm, but technically isn’t released so would need to pin via commit hash. I’d be happy to help with setup/usage if you go that route.