Linux version does not have a nice dialog box for changing configuration.

Please
modify configuration files manually. The configuration files are located under
config directory.

[flight.cfg]
SMOKETYPE Type
Type can be one of NOODLE, TOWEL, CIRCLE, or SOLIDh
SMOKETIME 30.000000
Time (in seconds) that a smoke trail remains visible.
SMOKESTEP 4
Resolution of a smoke trail. A smaller number gives a better
smoke trail, but takes longer time to draw.
DRWSHADOW TRUE/FALSE
Specify if the program draws shadows.
HRIZNGRAD TRUE/FALSE
Specify if the program draws gradation near horizon.
This setting is ignored DRAWFOG__ is TRUE.
DRAWCLOUD TRUE/FALSE
Specify if the program draws clouds.
GBLACKOUT TRUE/FALSE
Specify if the prgram darkens when high positive G is applied and
reddens when high negative G is applied.
ACCURATET TRUE/FALSE
If it is FALSE, the program does a kind of corner-cutting to
reduce computational time for calculating airplane dynamics.
AUTORUDDR TRUE/FALSE
Enables/disasbles automatic-rudder coordinator.
MIDAIRCOL TRUE/FALSE
Enables/disables mid air collision (actually, not necessarily
in mid air though.)
SHADWDEAD TRUE/FALSE
Specify if the program draws shadows of dead airplanes.
This setting is ignored if DRWSHADOW is FALSE.
DRAWORDIN TRUE/FALSE
Specify if the program draws weapons loaded on
airplanes.
COARSEWPN TRUE/FALSE
Specify if the program draws coarse weapons.
DRAWFOG__ TRUE/FALSE
Specify if the program draws fog. If this setting is TRUE,
HRIZNGRAD is ignored.
VISIBILIT 20000.00m
Specify the visibility. You need to have unit (m) at the
end without separating by a space or a tab.
ZBUFFQUAL 0,1,2, or 3
Specify the quality of Z-Buffering.
0:lowest but fastest
3:highest but slowest.
DEFAIRPLN "F-16C_FIGHTINGFALCON"
Specify the default player airplane.
HUDALWAYS FALSE
Specify if the program draws the head up display.
JSCALIBRA FALSE
Specify if the program re-calibrates joystick at the startup.
Apparently, my calibration routine is not very good, and
shouldn't set this setting TRUE :-P
AIRLVODTL 0,1,2, or 3
Specify the quality of airplane graphics.
 0:Default (use a coarse model when an airplane is far from the viewpoint)
1:Always high quality
2:Always coarse
3:Paper airplane
GNDLVODTL 0,1, or 2
Specify the quality of ground object graphics.
0:Default (use a coarse model when an airplane is far from the viewpoint)
1:Always high quality
2:Always coarse
DRWPLRNAM TRUE/FALSE
If it is FALSE, player name is visible only when the head up display
is visible.
DRWLITDAY TRUE/FALSE
If it is FALSE, runway lights and city lights are invisible when
the environment is day.
TRANSPARE TRUE/FALSE
If it is TRUE, afterburners and cockpit windows (planned) become
semi-transparent.
TRSPVAPOR TRUE/FALSE
If it is TRUE, vapor trails are drawn semi-transparent.
TRSPSMOKE TRUE/FALSE
If it is TRUE, smoke trails are drawn semi-transparent.
LANDANWHR TRUE/TRUE
If it is TRUE, airplanes can land anywhere. However, if the
speed exceeds 15kt and lands out of runway, airplane vibrate
violently and may end up with crashing.
ENVIRONME DAY/NIGHT
Specify environment.
DEFFIELD_ "ATSUGI_AIRBASE"
Specify the default field.
DEFSTPOS_ "RW01_01"
Specify the default start position.
JSWARNING TRUE/FALSE
If TRUE, the program shows the warning message "Joystick is not
connected or not configured" when a joystick axis is assigned to a
control function and joystick is not detected.
TRSPLATER TRUE/FALSE
If TRUE, transparent polygons are drawn after all non-transparent
polygons. It reduces the peep hole effect caused by a transparent
polygon.
CAMERADLY TRUE/FALSE
If TRUE, the external airplane camera, initially F8 key is assigned,
will chase the airplane with some delay.

[network.cfg]
USEMISSILE TRUE/FALSE
Specify whether the server allows air to air missiles.
SERVERWAIT TRUE/FALSE
(Not used now)
DEFAULTHST ""
Specify the default host name in the client mode.
PORTNUMBER 7915
Specify the default port number.
DEFAULTUSR "USERNAME"
Specify the default user name. If you use "USERNAME", the program
automatically gives you "Nameless."
RECORDCLNT TRUE/FALSE
 Specify whether the program takes flight record in the client mode.
RECORDSRVR TRUE/FALSE
Specify whether the program takes flight record in the server mode.
DEFLTFIELD "NEWTA_AIRBASE"
Specify the default field name in the server mode.
DFSTPOSSVR "NORTH10000_01"
Specify the default start position in the server mode.
DEFIFFSRVR 0,1,2, or 3
Specify the default IFF (identify friend or foe) code in the server mode.
DEFIFFCLNT 0,1,2, or 3
Specify the default IFF code in the client mode.
DFSTPOSCLI "SOUTH10000_01"
Specify the default start position in the client mode.
GROUNDFIRE TRUE/FALSE
Specify whether the server allows ground to air fire.
FREECLIENT TRUE/FALSE
Specify whether the program frees memory when possible in the client mode.
Actually, there are many problem reports including the server crash
problem when this setting is TRUE. The cause of the server crash
is still unknown and I could not re-produce the same problem in
my environment. I only could make some defensive modifications,
so, you may want to turn this setting off if you experience problems
during playing over network.
FREESERVER TRUE/FALSE
Specify whether the program frees memory when possible in the server mode.
Actually, there are many problem reports including the server crash
problem when this setting is TRUE. The cause of the server crash
is still unknown and I could not re-produce the same problem in
my environment. I only could make some defensive modifications,
so, you may want to turn this setting off if you experience problems
during playing over network.
SENDBLKOUT TRUE/FALSE
If it is TRUE, the server sends the "GBLACKOUT" setting of flight.cfg to
clients. Otherwise, clients uses their own "GBLACKOUT" setting.
SENDLDAWHR TRUE/FALSE
If it is TRUE, the server sends the "LANDANWHR" setting of flight.cfg to
clients. Otherwise, clients uses their own "LANDANWHR" setting.
SENDMIDAIR TRUE/FALSE
If it is TRUE, the server sends the "MIDAIRCOL" setting of flight.cfg to
clients. Otherwise, clients uses their own "MIDAIRCOL" setting.
NOGUNSIGHT TRUE/FALSE
If it is TRUE, all the clients connected to the server do not show lead
gun sight regardless the local configuration.
SAMEVERSIN TRUE/FALSE
If it is TRUE, the server only accepts connection from clients of the
same YSFLIGHT version.
SVRRESETTM Nmin
If other than 0min is specified, the server resets itself once every N
minutes. Warning messages are sent to the clients 30, 15, 10, 5, and 1
minutes before resetting.
ENTSVRAFTR M
If non zero minutes is specified for SVRRESETTM, the server will terminate
automatically after resetting M times. By using SVRRESETTM and ENTSVRAFTR
together, you can set up a server that runs specific duration of time.
For example, if you set as:

SVRRESETTM 360min
ENTSVRAFTR 9
 The server runs 360 minutes times 9 = 3240 minutes, which corresponds to
54 hours. If you set up a task scheduler so that it starts a server at
6pm every Friday with the following command line:

ysflight -server AutoServer -autoexit

The server starts at 6pm on Friday, and terminates 0am on Monday.

[option.cfg]
SCREENMOD 0
Ignored in Linux version.
SOUND TRUE
Ignored in Linux version.
OPENDEMO TRUE/FALSE
If it is true, the program shows opening dogfight demonstration.

[ctlassign.cfg]
Joystick Axis Assignment
AXS joyId joyAxs AxisFunction
or
AXS joyId joyAxs AxisFunction REV

joyId='M' means mouse

Joystick Trigger Assignment

joyTrg must be 0<=joyTrg<=7

Keyboard Assignment
KEY keyCode ButtonFunction

List of AxisFunctions
NULL NULL
AILERON Aileron
ELEVATOR Elevator
THROTTLE Throttle
RUDDER Rudder
FLAP Flap
LANDINGGEAR Landing Gear
TRIM Elevator Trim
NOZZLE VTOL Nozzle Up/Down (Nose for Concorde)
VGW Variable Geometry Wing
SPOILERBRAKE AirBrake + Brake
SPOILER AirBrake
BRAKE Brake
POVX X Axis of Point of View
POVY Y Axis of Point of View
List of ButtonFunctions
NULL NULL
ELEVATORUP Elevator Up
ELEVATORNEUTRAL Elevator Neutral
ELEVATORDOWN Elevator Down
AILERONLEFT Aileron Left
AILERONNEUTRAL Aileron Neutral
AILERONRIGHT Aileron Right
RUDDERLEFT Rudder Left
RUDDERCENTER Rudder Center
RUDDERRIGHT Rudder Right
TRIMUP Elevator Trim Up
TRIMDOWN Elevator Trim Down
AUTOTRIM Auto Trim
THROTTLEUP Throttle Add Power
THROTTLEDOWN Throttle Reduce Power
THROTTLEMAX Throttle Max
THROTTLEIDLE Throttle Min (Idle)
AFTERBURNER Afterburner
NOZZLEUP Nozzle Up (Nose Up for Concorde)
NOZZLEDOWN Nozzle Down (Nose Down for Concorde)
VGWEXTEND Extend Variable Geometry Wing
VGWRETRACT Retract Variable Geometry Wing
LANDINGGEAR Landing Gear Extend/Retract
FLAP Flap Up/Down
FLAPUP Flap Up
FLAPDOWN Flap Down
FLAPFULLUP Flap Full Up
FLAPFULLDOWN Flap Full Down
SPOILERBRAKE Spoiler and Brake On/Off
SPOILER Spoiler Extend/Retract
SPOILEREXTEND Spoiler Extend
SPOILERRETRACT Spoiler Retract
SPOILERHOLD Spoiler On When Pressed
BRAKEONOFF Brake On/Off
BRAKEHOLD Brake On When Pressed
FIREWEAPON Fire Selected Weapon
FIREGUN Fire Machine Gun
FIREAAM Fire AAM
FIREAGM Fire AGM
FIREROCKET Fire Rocket
DROPBOMB Drop Bomb
DISPENSEFLARE Dispense Flare
SMOKE Smoke
SELECTWEAPON Select Weapon
RADAR Radar
RADARRANGEUP Radar Range Up
RADARRANGEDOWN Radar Range Down
ILS ILS On/Off
VELOCITYINDICATOR Velocity Indicator On/Off
OPENAUTOPILOTMENU Open Autopilot Menu
OPENRADIOCOMMMENU Open Radio Comm Menu
COCKPITVIEW Cockpit View
OUTSIDEPLAYERVIEW Outside Player View
COMPUTERAIRPLANEVIEW Computer Airplane View
WEAPONVIEW Weapon View
ILSVIEW ILS View
OUTSIDEPLAYERVIEW2 Outside Player View 2
OUTSIDEPLAYERVIEW3 Outside Player View 3
 CONTROLTOWERVIEW Control Tower View
CHANGEAIRPLANE Change Airplane in Replay Record Mode
LOOKFORWARD Look Forward
LOOKRIGHT Look Right
LOOKLEFT Look Left
LOOKBACK Look Back
LOOKUP Look Up
LOOKDOWN Look Down
REVERSETHRUST Reverse Thrust
OPENSUBWINDOWMENU Open Sub-Window Menu
CHANGEHUDCOLOR Change HUD Color
PAUSESIMULATION Pause Simulation
GHOSTVIEW Ghost View
OPENVORMENU Select VOR
ROTATEVORLEFT Rotate VOR to the Left
ROTATEVORRIGHT Rotate VOR to the Right
BOMBBAYDOOR Open/Close Bomb Bay Door
INFLIGHTCFG In-Flight Config Change

List of KeyCodes
SPACE Space
0 0
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
A A
B B
C C
D D
E E
F F
G G
H H
I I
J J
K K
L L
M M
N N
O O
P P
Q Q
R R
S S
T T
U U
V V
W W
X X
Y Y
Z Z
ESC Esc
F1 F1
F2 F2
F3 F3
F4 F4
F5 F5
F6 F6
F7 F7
F8 F8
F9 F9
F11 F11
F12 F12
CAPSLOCK Caps Lock
SCROLLLOCK Scroll Lock
PAUSEBREAK Pause
BS Backspace
TAB Tab
ENTER Enter
SHIFT Shift
CTRL Ctrl
INS Insert
DEL Delete
HOME Home
END End
PAGEUP Page Up
PAGEDOWN Page Down
UP Up Arrow
DOWN Down Arrow
LEFT Left Arrow
RIGHT Right Arrow
NUMLOCK Num Lock
TILDA ~
MINUS -
PLUS +
LBRACKET [
RBRACKET ]
BACKSLASH \
SEMICOLON ;
SINGLEQUOTE '
COMMA ,
DOT .
SLASH /
TEN0 0 (NUMPAD)
TEN1 1 (NUMPAD)
TEN2 2 (NUMPAD)
TEN3 3 (NUMPAD)
TEN4 4 (NUMPAD)
TEN5 5 (NUMPAD)
TEN6 6 (NUMPAD)
TEN7 7 (NUMPAD)
TEN8 8 (NUMPAD)
TEN9 9 (NUMPAD)
TENDOT . (NUMPAD)
TENSLASH / (NUMPAD)
TENSTAR * (NUMPAD)
TENMINUS - (NUMPAD)
TENPLUS + (NUMPAD)