Re: Performance tests of quoting and dequoting, printf -v turned out slow

[Stephane Chazelas <stephane.chazelas@xxxxxxxxx>]

2018-03-09 07:22:46 +0100, Sebastian Gniazdowski:
> Hello
> Two scripts:
> 
> - short.txt
> Test of quoting, (q)-flag vs. printf -v output '%q '
> result: 35 ms vs. 26.6 sec
> 
> - Q_short.txt – test of dequoting, (Q)-flag vs. eval "str=$quoted"
> result: 25 ms vs. 77 ms
> 
> I've compared "printf -v" code to Bash 4.4 and it yields 227
> ms there, so much better than 26.6 sec. So while "Bash can
> serialize/deserialize too, let's compare speed of this method"
> is interesting thing and I share, performance of "printf -v"
> on Zsh is troubling. Any idea from where it comes from and if
> it can be improved?
[...]

I can't reproduce with zsh 5.4.2 (x86_64-debian-linux-gnu)
compared with 4.4.18(1)-release (x86_64-pc-linux-gnu).
in a en_GB.UTF-8 locale.

FWIW, I find:

$ time INPUT='ice as"program" pick"$ZPFX/bin/prll_(qer|bfr)" src"prll.sh" make"install PREFIX=$ZPFX"' bash -c 'for ((i = 0; i < 50000; i++)); do printf -v OUTPUT %q "$INPUT"; done'
INPUT= bash -c   1.48s user 0.00s system 99% cpu 1.485 total
$ time INPUT='ice as"program" pick"$ZPFX/bin/prll_(qer|bfr)" src"prll.sh" make"install PREFIX=$ZPFX"' zsh -c 'for ((i = 0; i < 50000; i++)); do printf -v OUTPUT %q "$INPUT"; done'
INPUT= zsh -c   0.83s user 0.14s system 99% cpu 0.979 total

What's your version and locale?

-- 
Stephane