--referer is misspelled; should be --referrer, or tell the user what they did wrong

[ZevEisenberg]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2020.07.28
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar bug reports including closed ones
• I've read bugs section in FAQ

Verbose log

youtube-dl -v --referrer "whatever" "https://www.youtube.com/watch\?v\=0k3l9IqsbTs"
Usage: youtube-dl [OPTIONS] URL [URL...]

youtube-dl: error: no such option: --referrer

Description

The --referer parameter is a possibly intentional misspelling of the English word "referrer". When typing a command, an inexperienced user may not notice the misspelling, spell the word "correctly" (i.e. not the way youtube-dl spells it), and be confused by the error message: error: no such option: --referrer.

youtube-dl should either accept --referrer as an alias to --referer, since it's clear what the user wanted to do, or should give a more helpful error message, such as did you mean --referer?

[dstftw]

This is intentional. Also neither wget nor curl have such an alias.

[ZevEisenberg]

This seems like an unwelcoming approach to newcomers of the software. If you can take what the user typed and figure out, unambiguously, what they meant, why not help them out?

I also think wget and curl should either add aliases, or add a general flag spell-checker, for the same reason.

I can't believe I'm about to use Git as an example of good user experience, but it has a similar-command matcher in it. Watch what happens when I misspell a command:

$ git pul              
git: 'pul' is not a git command. See 'git --help'.

The most similar commands are
	pull
	push

Why do I care so much about referrer in particular? We don't always read words letter-by-letter. It could frustrate someone to an unreasonable degree to be told that --referrer isn't a valid command, when the man page said that --referer is, if they don't notice the spelling difference. CLIs are unapproachable enough without introducing diabolical traps like intentional spelling mistakes! Making someone notice an obscure (and intentional!) typo feels like a tech interview gone wrong.