Install instructions for Fish are wrong about thefuck HOT 9 CLOSED

Thanks.

from thefuck.

@kballard, the bits about waste, quoting and sourcing instead of evaling are spot-on, but are you sure about history also including the currently running command?

$ echo foo
foo
$ echo (history | head -n1)
echo foo

Conversely, I find that history[2] yields the second-to-last command:

$ echo foo
foo
$ echo bar
bar
$ echo $history[2]
echo foo

This is with fish v2.1.1,

from thefuck.

That's odd. My several-months-old dev version of Fish 2.1.1, and my just-installed tip-of-master version of Fish 2.1.2, both behave as I described:

> echo foo
foo
> echo (history | head -n1)
echo (history | head -n1)
> echo foo
foo
> echo bar
bar
> echo $history[2]
echo bar

from thefuck.

I can see mentions of $history[1] in various threads:

• fish-shell/fish-shell#984
• fish-shell/fish-shell#288

Where ridiculousfish themself agree that it should return the last
executed command.

May be a difference in arch/plugins/etc? For comparison, this is Fish
v2.1.1 installed with Homebrew on OSX.

from thefuck.

I'm also running OS X.

I'm wondering now if maybe master has a bug where it's adding the command to history too eagerly. Note that master actually has a lot of changes from 2.1.2 (I believe master has been considered to be equivalent to at least 2.2 for a long time, and 2.1.1 / 2.1.2 were just minor changes from 2.1.0).

Given the state of things at the moment, I guess the install instructions should be changed to use $history[1] instead of $history[2] until this can be tracked down.

from thefuck.

Yep, the commit referenced in that issue fish-shell/fish-shell#984 (aa1b065dd1c03f7c0867d002badcf0dc88feb3c4) is the culprit. Building fish from before that commit expands $history[1] to the previous command instead of the current one. That commit is only on master, it's not in v2.1.2.

from thefuck.

Here is a repeatable test on a completely pristine machine from instantcloud.io with even older fish 2.1.0:

from thefuck.

I've filed fish-shell/fish-shell#2028 about this issue.

In the meantime, @nvbn, it seems clear that the instructions need to be changed to say $history[1] instead of $history[2] (but other than that, the new function is better than the old).

from thefuck.

I agree, if not only for the quoting and eval issues.

Performance is also (predictably) way better:

$ time -p fish -c 'for a in (seq 1000); history | head -n1 > /dev/null; end'
real         3.25
user         2.06
sys          1.58

$ time -p fish -c 'for a in (seq 1000); echo $history[1] > /dev/null; end'
real         1.32
user         0.65
sys          0.84

from thefuck.