That's common on linux. Many tools read from stdin if a file path isn't given: cat, xargs, base64, cksum, etc.
The citation thing is a little silly, I'll give you that one.
No. I did pipe to stdin. It's not my first time using Linux...
Here's a command line I ran right now, and the output I see:
$ echo "http://www.example.com" | parallel -k -j 8 curl -s "{}"
Academic tradition requires you to cite works you base your article on.
[...more nonsense...]
To silence this citation notice: run 'parallel --citation' once.
parallel: Warning: Finding the maximal command line length. This may take up to 1 minute.
So I Ctrl+C. And then the parent perl process gets killed, but the child apparently keeps running.
I press Ctrl+D to exit the terminal, and then:
$ # (Ctrl+D pressed)
logout
xargs Just Works without any of this nonsense, yet somehow I'm the one holding GNU parallel wrong?
> So I wait a few seconds [snip]
This warning is only ever printed if running in Cygwin, not Linux or macOS or elsewhere. Cygwin is notoriously slow.
# This is slow on Cygwin, so give Cygwin users a warning
if($^O eq "cygwin" or $^O eq "msys") {
::warning("Finding the maximal command line length. ".
"This may take up to 1 minute.")
}
Try reading some time. It's pretty great.
> the Ctrl+C handling is just utterly broken
That's your terminal, not parallel.
> and all of the delays
Your terminal is adding the delay, not parallel. parallel is just warning you about your broken terminal. You're shooting the messenger here.