DOCS/input: simpler solution to handle sh metacharacters with run

[emanuele6]

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Also rephrase "To get the old behavior" as "If you want to use shell features".

Screenshot:

[avih]

Not sure about this. While technically correct, it's a bit misleading in two ways:

• The first argument to sh is - but it's not clear why it's there (I know why, but it's not clear at the docs).
• The example where you use "$1" makes it look as if (mpv) properties are not expanded due to single quotes - but that's not true. Single quotes doesn't prevent mpv properties expansion, and it's not expanded because it's not ${ or $> or $$, but if you used "${1}" then mpv would try to expand it and error out. So (mpv argument) single quotes are not a general solution for a shell line - but your example makes it look like it is.

Also, the text is a bit too verbose for my taste with the metacharacters etc. It's suffice IMHO to say that it avoid the need for escaping the actual value.

Overall, the text should be shorter and without gotchas.

[emanuele6]

Yeah, I am aware I should have used $$ instead of just $ (I use that in my personal bindings even when not strictly necessary because I don't like to have special characters unescaped).

There I was just trying to shorten the line as much as possible since that line is indented a lot and it is hard to read on a 80x24 terminal window. But, you are right that that could be misleading. I will add it back since the line won't fit on one line in a small terminal anyway.

I also would not have mentioned the "potential code injection attack", but I did since it was already mentioned in the original text, I will happily remove it.

I will make the note less verbose and add an addendum for - (that I changed to _ since some shells ignore - instead of using it to set $0).

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EDIT: Screenshot

[avih]

Yeah, I am aware I should have used $$ instead of just $

That would work, but looks clumsy IMHO (it is a matter of taste though), and if more arguments are used then it becomes messier.

Maybe something like run sh -c '$> SHELL-CONTENT' xx "${title}" ? (with an actual shell code).

The single quotes prevent string escpes interpretation (backslash), the $> at the begining of the argument prevents mpv expansion, and the quotes for "${title}" because officially all arguments should be quoted.

Also, you should ignore the terminal width. The manpage is aligned it to the terminal width automatically, and except for example strings which preferably fit to 60 chars or so, all other text should be arbitrary. Don't "design" for manpage in 80 cols term.

[emanuele6]

I rebased the commit onto master. Is this PR ready to be merged or should I change something else?

[emanuele6]

I changed the commit message to DOCS/input: ... as suggested in https://github.com/mpv-player/mpv/pull/10153#issuecomment-1114851970

[zDEFz]

Relevant: Had to find out c run "/usr/bin/bash" "-c" "echo ${filename/no-ext} | xsel -ib" doesnt really work. However, c run "/usr/bin/bash" "-c" "printf '%s' \"${filename/no-ext}\" | xsel -ib" does.

Test string 20221110 「死にたいわけじゃなくて」⧸ 可不(KAFU) - l3UvRTpHqKY

Please consider a update.