If you have an actual home key. If it's ctrl+a or (IIRC, AFK) ctrl+← then we're even.

And if we track hand movements then pressing ! twice may be faster than moving to another key.

But yeah, it's not at all clear that sudo !! is faster like you'd expect it to be.

Actually, after kinematic analysis of the required fingertip trajectories upheaves both of these arguments. If you calculate the aggregate spatial displacement across a standard 2D Euclidean plane for both input strings, the former macro sequence yields a significantly lower metric footprint than the latter.

For the sake of empirical demonstration, we can map this across a standard ANSI 100% layout using a normalized key pitch constraint where 1 U = 19.05 mm. By establishing a Home Row Idle-State Matrix as our behavioral anchor and tracking independent multi-finger vectors using the standard Pythagorean metric tensor—calculating the straight-line distance d = sqrt( delta_x^2 + delta_y^2 ) between consecutive keystroke coordinates—we arrive at the following quantitative breakdown:

Macro Sequence 1: sudo [shift] !! [enter]

• Single-Handed Vector String: 40.878 U
  • Net Linear Displacement: 778.7 mm
• Dual-Handed Touch-Typing Matrix: 8.424 U
  • Net Linear Displacement: 160.5 mm

Macro Sequence 2: [up] [home] sudo [space] [enter]

• Single-Handed Vector String: 40.989 U
  • Net Linear Displacement: 780.8 mm
• Dual-Handed Touch-Typing Matrix: 21.728 U
  • Net Linear Displacement: 413.9 mm

tl;dr

Fewer keystrokes != less work. Even though typing !! looks like more work, it isn't because your finger travel distance is significantly shorter when executing those keys using two-handed touch typing on a standard ANSI QWERTY keyboard.

I don't dabble in black magic. /j

It's actually pretty neat.

I know what you meant (I have one for fish as well), but I chucked because you looked very enthusiastic about it!

The fish function for !! is super useful though

echo $SHELL

Same reason there's a ScrollLock key on keyboards. Didn't always have scrollbars and if the application prints more than you can read, you want to pause that...

Short answer, terminals are built on the same technology as physical terminals from the 60s and 70s when controlling the flow of data from the server was a more useful feature.

Seem to be a fish shell thing.

I tested on my good ole trusty bash and got nothing so I went searching.

EDIT: Clarification : alt+s seems to be a fish shell thing.