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Re: strange interaction between read command and pipe to less from function

X-seq: zsh-users 28987
From: Lawrence Velázquez <larryv@xxxxxxx>
To: Jim <linuxtechguy@xxxxxxxxx>
Cc: "Roman Perepelitsa" <roman.perepelitsa@xxxxxxxxx>, zsh-users@xxxxxxx
Subject: Re: strange interaction between read command and pipe to less from function
Date: Sun, 26 Mar 2023 19:50:33 -0400
Archived-at: <https://zsh.org/users/28987>
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On Sun, Mar 26, 2023, at 1:23 PM, Roman Perepelitsa wrote:
> On Sun, Mar 26, 2023 at 7:04 PM Jim <linux.tech.guy@xxxxxxxxx> wrote:
>>
>> Now I'm totally confused.  A bit by your answer and the word 'simultaneously'
>> as I thought the function would run first then less.
>
> When you run `cvt_256_colors_2_rgb_hex_fmt | less`, two processes run
> simultaneously. One is executing `cvt_256_colors_2_rgb_hex_fmt`, the
> other is executing `less`.

A demonstration:

	% foo() for arg do print -n $arg >$TTY; done
	% repeat 10 do foo {a..j} | foo {0..9}; echo; done
	0ab1c2d3e4f5gh6i7j89
	0a1b2c3de4f5g6h7i8j9
	01a2b3c4d5e6fg7h8i9j
	0a1bc2de3fgh4ij56789
	01ab2c3d4e5f6g78h9ij
	01a2b34c56d78e9fghij
	0a1bc2de3fgh4ij56789
	ab0cd1ef2gh3ij456789
	a0bc1d2e3f4g5h6i7j89
	0ab1c2d3ef4gh5i6j789

Note the nondeterministic output.

-- 
vq

References:
- strange interaction between read command and pipe to less from function
  - From: Jim
- Re: strange interaction between read command and pipe to less from function
  - From: Roman Perepelitsa
- Re: strange interaction between read command and pipe to less from function
  - From: Jim
- Re: strange interaction between read command and pipe to less from function
  - From: Roman Perepelitsa
- Re: strange interaction between read command and pipe to less from function
  - From: Jim
- Re: strange interaction between read command and pipe to less from function
  - From: Roman Perepelitsa

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