/usr/lib/games/nethack/hh is in nethack-common 3.6.0-4+b1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | y k u   7 8 9   Move commands:
 \|/     \|/            yuhjklbn: go one step in specified direction
h-.-l   4-.-6           YUHJKLBN: go in specified direction until you
 /|\     /|\                        hit a wall or run into something
b j n   1 2 3           g<dir>:   run in direction <dir> until something
      numberpad                     interesting is seen
                        G<dir>,   same, except a branching corridor isn't
 <  up                  ^<dir>:     considered interesting (the ^ in this
                                    case means the Control key, not a caret)
 >  down                m<dir>:   move without picking up objects/fighting
                        F<dir>:   fight even if you don't sense a monster
                If the number_pad option is set, the number keys move instead.
                Depending on the platform, Shift number (on the numberpad),
                Meta number, or Alt number will invoke the YUHJKLBN commands.
                Control <dir> may or may not work when number_pad is enabled,
                depending on the platform's capabilities.
                Digit '5' acts as 'G' prefix, unless number_pad is set to 2
                in which case it acts as 'g' instead.
                If number_pad is set to 3, the roles of 1,2,3 and 7,8,9 are
                reversed; when set to 4, behaves same as 3 combined with 2.
                If number_pad is set to -1, alphabetic movement commands are
                used but 'y' and 'z' are swapped.
General commands:
?       help    display one of several informative texts
#quit   quit    end the game without saving current game
S       save    save the game (to be continued later) and exit
!       sh      escape to some SHELL (if allowed)
^Z      suspend suspend the game (independent of your current suspend char)
O       options set options
/       whatis  tell what a map symbol represents
\       known   display list of what's been discovered
v       version display version number
V       history display game history
^A      again   redo the previous command (^A denotes the keystroke CTRL-A)
^R      redraw  redraw the screen
^P      prevmsg repeat previous message (subsequent ^P's repeat earlier ones)
#               introduces an extended command (#? for a list of them)
Game commands:
^D      kick    kick (a door, or something else)
^T      'port   teleport (if you can)
^X      show    show your attributes
a       apply   apply or use a tool (pick-axe, key, camera, etc.)
A       armor   take off all armor
c       close   close a door
C       call    name a monster, an individual object, or a type of object
d       drop    drop an object.  d7a:  drop seven items of object 'a'
D       Drop    drop selected types of objects
e       eat     eat something
E       engrave write a message in the dust on the floor  (E-  use fingers)
f       fire    fire ammunition from quiver
F       fight   followed by direction, fight a monster
i       invent  list your inventory (all objects you are carrying)
I       Invent  list selected parts of your inventory
                Iu: list unpaid objects
                Ix: list unpaid but used up items
                I$: count your money
o       open    open a door
p       pay     pay your bill (in a shop)
P       puton   put on an accessory (ring, amulet, etc)
q       quaff   drink something (potion, water, etc)
Q       quiver  select ammunition for quiver
r       read    read a scroll or spellbook
R       remove  remove an accessory (ring, amulet, etc)
s       search  search for secret doors, hidden traps and monsters
t       throw   throw or shoot a weapon
T       takeoff take off some armor
w       wield   wield a weapon  (w-  wield nothing)
W       wear    put on some armor
x       xchange swap wielded and secondary weapons
X       twoweapon toggle two-weapon combat
z       zap     zap a wand  (use y instead of z if number_pad is -1)
Z       Zap     cast a spell  (use Y instead of Z if number_pad is -1)
<       up      go up the stairs
>       down    go down the stairs
^       trap_id identify a previously found trap
),[,=,",(       ask for current items of specified symbol in use
*               ask for combination of ),[,=,",( all at once
$       gold    count your gold
+       spells  list the spells you know; also rearrange them if desired
`       classkn display known items for one class of objects
_       travel  move via a shortest-path algorithm to a point on the map 
.       rest    wait a moment
,       pickup  pick up all you can carry
@               toggle "pickup" (auto pickup) option on and off
:       look    look at what is here
;       farlook look at what is somewhere else by selecting a map symbol
Keyboards that have a meta key can also use these extended commands
via the meta modifier instead of the # prefix:
M-?             display extended command help (if the platform allows this)
M-2     twoweapon toggle two-weapon combat (unless number_pad is enabled)
M-a     adjust  adjust inventory letters
M-c     chat    talk to someone
M-d     dip     dip an object into something
M-e     enhance advance or check weapon and spell skills
M-f     force   force a lock
M-i     invoke  invoke an object's special powers
M-j     jump    jump to another location
M-l     loot    loot a box on the floor
M-m     monster use a monster's special ability
M-n     name    name a monster, an individual object, or a type of object
M-o     offer   offer a sacrifice to the gods
M-p     pray    pray to the gods for help
M-q     quit    stop playing
M-r     rub     rub a lamp or a stone
M-s     sit     sit down
M-t     turn    turn undead
M-u     untrap  untrap something
M-v     version print compile time options for this version
M-w     wipe    wipe off your face
If the "number_pad" option is on, these additional variants are available:
n               followed by number of times to repeat the next command
h       help    display one of several informative texts, like '?'
j       jump    jump to another location
k       kick    kick something (usually a door)
l       loot    loot a box on the floor
N       name    name an item or type of object
u       untrap  untrap something (usually a trapped object)
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