Find your L4D2's catalog, for example: D:\steam\steamapps\common\Left 4 Dead 2\left4dead2
Find "cfg" file，click in，create a new text file, rename as "autoexec.cfg" CAUTION! MUST BE .cfg !
//In case of script conflict that you can't join your friend's lobby
sv_consistency 0


//Full-Auto Weapon，alias "+Rm" "alias Ps Rm1;Rm1"
alias "Rm1" "+attack;wait 5;-attack;Rm2"
alias "Rm2" "wait 5;+attack;wait 5;-attack;Ps"
alias "-Rm" "-attack;alias Ps;Rm;-attack"
//bind "mouse4" "+Rm" //<--Key bind，this is binding mouse 4, you can change the key whatever you want, suit yourself

//Fast idle, can be use for cancel dizzying and light the witch
bind "B" "go_away_from_keyboard" //<--Key bind，this is bindingB

//Perminant duck, press space or duck can cancel it, can be use relax your left pinky
bind 6 "toggle_duck" //<——绑定按键，这里是绑定了数字6

//Perminant Toggle walk, press again can cancel it, can be use foray little zombies
alias ToggleWalk ToggleWalkOn
alias ToggleWalkOn "+speed;alias ToggleWalk ToggleWalkOff"
alias ToggleWalkOff "-speed;alias ToggleWalk ToggleWalkOn"
bind "Shift" "ToggleWalk" //<——绑定按键，这里是绑定了左Shift

//Fast melee, can save the slow melee like Guitar, but may error in low FPS condition!
alias speedcut "+attack;wait 5;lastinv;wait 5;lastinv;-attack"
bind "mouse5" "speedcut" //<——绑定按键，这里是绑定了鼠标第5键

alias ceiling_bind "+attack;wait 2;-attack;wait 2;ceiling_jump"
alias ceiling_alias "alias ceiling_jump ceiling_bind"
alias ceiling_stop "alias ceiling_jump"
alias +ceiling "ceiling_alias;ceiling_jump"
alias -ceiling "ceiling_stop;-attack"

//Third Person Shoulder, it's adjusted by me but still have some flaw, can change your camera by direction arrow button
cam_snapto 0;
c_thirdpersonshoulderoffset 20
bind "alt" "thirdpersonshoulder; 3dr_person" //<——绑定按键，这里是绑定了Alt
bind "LEFTARROW" L-frontcam
bind "UPARROW" L-biendcam
bind "RIGHTARROW" R-frontcam
bind "DOWNARROW" R-biendcam
alias 3dr_person "cl_viewmodelfovsurvivor 80; cl_crosshair_dynamic 1;
c_thirdpersonshoulderdist 40; c_thirdpersonshoulderaimdist 720; c_thirdpersonshoulderheight -10;"
alias L-frontcam "c_thirdpersonshoulderoffset 20; cam_idealyaw 150; cam_snapto 0;"
alias L-biendcam "c_thirdpersonshoulderoffset 20; cam_idealyaw 0; cam_snapto 1;"
alias R-frontcam "c_thirdpersonshoulderoffset -20; cam_idealyaw -150; cam_snapto 0;"
alias R-biendcam "c_thirdpersonshoulderoffset -20; cam_idealyaw 0; cam_snapto 1;"

//Auto Bunny Jump (Not so great)///*bind space "+ajump"

alias +ajump "+jump; alias ajump3; alias autoj1 autoj; hjump1; wait 16; ajump"

alias -ajump "-jump; alias ajump1 alias ajump1 autoj; alias autoj1; ajump3; hjump"

alias ajump "ajump1; ajump2"

alias ajump2 "alias ajump3 ajump1

alias ajump1 "autoj"

alias autoj "+jump; wait 4; -jump; wait 3; autoj1"

alias autoj1 "autoj"

alias hjump "alias hjump4 hjump3; hjump3; wait 15; alias hjump1; alias hjump4"

alias hjump3 "alias hjump1 hjump2; wait 1; hjump4"

alias hjump2 "alias ajump1 alias ajump1 autoj"*/

bind "9" "exec autobhop.cfg" //<——绑定按键，这里是绑定了9，以启动功能
bind "0" "bind space +jump" //<——绑定按键，这里是绑定了0，以禁用功能
//If you want to use this, you must create "autobhop.cfg"file, with the same way, then cope the following text into the new .cfg file:

bind space "+ajump"

alias +ajump "+jump; alias ajump3; alias autoj1 autoj; hjump1; wait 16; ajump"

alias -ajump "-jump; alias ajump1 alias ajump1 autoj; alias autoj1; ajump3; hjump"

alias ajump "ajump1; ajump2"

alias ajump2 "alias ajump3 ajump1

alias ajump1 "autoj"

alias autoj "+jump; wait 4; -jump; wait 3; autoj1"

alias autoj1 "autoj"

alias hjump "alias hjump4 hjump3; hjump3; wait 15; alias hjump1; alias hjump4"

alias hjump3 "alias hjump1 hjump2; wait 1; hjump4"

alias hjump2 "alias ajump1 alias ajump1 autoj"

//Fast text, you can edit them by yourself, but Only in English!
bind KP_END "say tank"
bind KP_DOWNARROW "say A f**king <J O C K E Y> around! I'm gonna f**k that son of b**ch's asshore!"
bind KP_PGDN "say medit"
bind KP_LEFTARROW "say this way"
bind KP_5 "say witch"
bind KP_RIGHTARROW "say Run! >_<"
bind KP_HOME "say F@ck u"
bind KP_UPARROW "say lol ^o^"
bind KP_INS "say WTF! O_O"
bind KP_DEL "say Motherf@cker!!!!!"
bind KP_PGUP "say !kill"

bind "g" "+mouse_menu AlertInfected" //<——绑定按键，这里是绑定了G
bind "v" "+mouse_menu public" //<——绑定按键，这里是绑定了V