Re: Slow history load with some values of HISTSIZE

[Casey Johnson]

That is more or less how I happened upon this behavior. I have been using bash 
for 20+ years and for most of that time I have had HISTSIZE and HISTFILESIZE 
large enough to be effectively unlimited. I recently took the time to learn the 
difference between HISTSIZE and HISTFILESIZE. I liked the idea of having a 
perpetual history (unlimited HISTFILESIZE) but only keeping the most recent 
entries in memory by default, since those are the most likely ones I would want 
to reuse. If I really want to mine the old entries on occasion, I can always 
bump up HISTSIZE and load the whole file. I think I started with something like 
HISTSIZE=25000 and was surprised by how long new terminals took to produce the 
first prompt. I started playing around with different values and it wasn't hard 
to guess that there was a whole lot of memmove() (or similar) happening.
________________________________
From: alex xmb sw ratchev <fxmbsw7@gmail.com>
Sent: Monday, February 5, 2024 7:29 PM
To: Dale R. Worley <worley@alum.mit.edu>
Cc: Casey Johnson <strykre@hotmail.com>; bug-bash <bug-bash@gnu.org>
Subject: Re: Slow history load with some values of HISTSIZE



On Mon, Feb 5, 2024, 18:09 Dale R. Worley 
<worley@alum.mit.edu<mailto:worley@alum.mit.edu>> wrote:
Casey Johnson <strykre@hotmail.com<mailto:strykre@hotmail.com>> writes:
>     In a clean shell, execute:
>             HISTFILE=alt-history.txt
>             HISTSIZE=150000
>             history -r
>     and then observe how long the last command runs before returning.

Though I expect that when you exit bash, the history file gets trimmed
to 150,000 lines, and then the "over 10 seconds to load" doesn't happen
again.

there is another HISTFILESIZE var
maybe ..

Dale