how a stray "j" ruined my evening

16 points by miro

repl

I am honestly puzzled by how anyone is meant to follow this article. I have read it several times and I still do not understand what the actual issue was. It feels as though the most important and interesting part, the precise cause of the problem, has been left out entirely.

After pasting the link into Firefox, it worked. What is going on? I send them the link and it works now...

So you sent them the same link they had sent you, and it worked for them now? The same link that had not worked earlier for them now worked for them? How is that possible?

but in ANSI newline delimiter is translated as "j"

It does not!? Did you mean ^J (Ctrl + J)? But how does Ctrl + J become j at the end of the link? What took the control code and changed it into j?

hayalci
I think what's going on is:
- the script copies links with '\n' to clipboard
- works fine for GUI applications, most/all ignore the whitespace
- OP installs a TUI signal client for the console
- Pasting the URL with '\n' to this TUI program turns it into "ORIGINAL_URL^J"
- OP gets complaints about URLs failing to load
- OP pastes the same clipboard content into web browser, browser happily loads, ignoring the whitespace at the end
- OP re-copies the URL from the browser's address bar, pastes back into chat, gets verification that it works (this is something I'd do as well)
- OP notices the URLs end with 'J' (possibly missing that they actually all end with '^J')
- OP figures out the newline issue and switches jq parameters for a permanent fix
Things that are adding to the confusion:
- "run-once-forget-forever shell script" -- what's that? is this snippet part of a larger script? This one is not "running" a command per se, only shortening urls. I personally would name a script "run-once-forget-forever" if it was running something in the background, with some web output, and copying the URL with outputs to clipboard.
- The fact that an image hosted on S3 is being shortened -- I guess tangentially related because the URL would be long, but I was expecting S3 to be the backend of the shortener service or something.
- "Time passes and I get the same responses from multiple friends" –- did the URLs break again after a while? I don't think so, I think what is meant is "later I shorten some other urls and send it via gurk to some other people, but I still get the same complaint, and once I tried in my local browser and re-sent the URL, they can access the second link"
Definitely agree that the article is not clear at all, but otoh it talks about a real issue with nonprintable char handling, edge cases, and provides practical JQ information (and the script is nice with demonstrations of; using a password database for URLs of personal services, the {VAR?ERROR_MESSAGE} validation)

TBH, I prefer this article much, much more over the LLM slop.
- miro
  
  Thanks for this! I should have done a better job explaining the underlying problem. Idea behind these posts (napkins) is to be very brief though here I shot myself in the foot with a paintball gun.
  
  I store files in a private bucket so when I want to share something I have to generate a presigned url that is around 300 characters long.
mdaniel

Turns out I was copying the link with a \n at the end, which in most cases went unnoticed, but in ANSI newline delimiter is translated as "j", hence the stray jay at the end of each link.

What does "in ANSI" mean in this context?
- WilhelmVonWeiner
  
  ANSI newline delimiter
  
  I figure the author means "in ANSI [terminal escape sequences] newline delimiter [\n] is translated as [ESC[J]"? Or ^J maybe. It's unclear what was happening.
  - fanf
    
    Yeah, what was turning the newline into an escape sequence? jq should have been piping ASCII 10 directly into the clipboard, so maybe something involved in pasting the newline mangled it?
    
    Also, there’s a stray j at the end of the gist link at the end of the article.
    
    miro
    
    i have removed the j at the end of the gist - it was my poor attempt at an easter egg I forgot to remove.
    
    It was written on a whim and looking back I should have delved more into the details.
    
    untitaker
    
    delved, you say?
    
    (ironically, i am hitting a claude code bug where pasting any text adds trailing j to any newline)
    
    miro
    
    aye, delved! English is not my first language so I either speak like a five year or as if i was a part of the British royal family, never in between.
    
    kghose
    
    Not clear on what is going on.
    
    Author passes a url to a link shortener and gets back a short link
    
    Author is using a tool that adds a new line to the response
    
    Author is using a copy command on the terminal that converts the new line to a lowercase “j” character when it puts it on the system clipboard?
    
    Do I have the last point correct?
    
    Garbi
    
    Didn't explain why it started working after a few minutes
    
    davidcox
    
    From the title I was expecting this to be about vim movement keys. If I had a dollar for every time I typed jjjjjkjk in the wrong terminal…