• Arguments are delimited by white space, which is either a space or a tab.
• The caret character (^) is not recognized as an escape character or delimiter. The character is handled completely by the command-line parser in the operating system before being passed to the argv array in the program.
• A string surrounded by double quotation marks ("string") is interpreted as a single argument, regardless of white space contained within. A quoted string can be embedded in an argument.
• A double quotation mark preceded by a backslash (\") is interpreted as a literal double quotation mark character (").
• Backslashes are interpreted literally, unless they immediately precede a double quotation mark.
• If an even number of backslashes is followed by a double quotation mark, one backslash is placed in the argv array for every pair of backslashes, and the double quotation mark is interpreted as a string delimiter.
• If an odd number of backslashes is followed by a double quotation mark, one backslash is placed in the argv array for every pair of backslashes, and the double quotation mark is "escaped" by the remaining backslash, causing a literal double quotation mark (") to be placed in argv.

• Tech note on passing command line parameters to any program

  On Windows, a new program is launched by calling the CreateProcess API, which takes the command line as a string (the lpComandLine parameter to CreateProcess). It's considered the responsibility of the newly started application to call the GetCommandLine API to retrieve that command line and parse it (possibly using the CommandLineToArgvW helper function).

  For programs written in C++, the C++ compiler adds prologue code to the executable which runs before the WinMain function. This prologue code calls the GetCommandLine API to retrieve the command line, then parses the command line extracting the parameters into argv[].

  If you disassemble AutoHotkey.exe you'll find the prologue code which parses the command line parameters into argv[]. It's not in the AutoHotkey source code, it was added by the C++ compiler. Therefore, the C++ compiler used to compile AutoHotkey determines how command line parameters are parsed.

  Since AutoHotkey is written in C++, the C++ compiler used to compile AutoHotkey determines how command line parameters are parsed.
  
  
  
  On Windows, parsing the command line parameters is performed by the application, not by the operating system. All the system offers is the GetCommandLine API, which hands the application the entire command line as one long string.

  This is why you'll get different results if you pass a command line with parameters to a C/C++ program (ShowParams.exe), a VBScript (ShowParams.vbs), or a batch file (ShowParams.bat)
  
  C/C++

  >ShowParams.exe  "c:\test a\"  "c:\test b\"
  param 1 = c:\test a" c:\test
  param 2 = b"
  ( \" is interpreted as meaning "a literal double quote.")
  

  VBScript

  >ShowParams.vbs  "c:\test a\"  "c:\test b\"
  param 1 = c:\test a\
  param 2 = c:\test b\
  

  Batch script

  >ShowParams.bat  "c:\test a\"  "c:\test b\"
  param 1 = "c:\test a\"
  param 2 = "c:\test b\"
  (the double quotes are included as part of the parameter)
  

  Parameters passed to a AutoHotkey script are parsed by AutoHotkey.exe, which is the program running the script. Parameters passed to a VBScript are parsed by WScript.exe (or possibly CScript.exe), which is the program running the VBScript. Parameters passed to a batch file are parsed by cmd.exe, which is the program that runs the batch script.

  Here are some test programs you can try:

  ShowParams.c
  #include "stdafx.h"
  int main(int argc, char* argv[])
  {
    for (int i = 0; i < argc; ++i)
    {
      printf("param %d = ",i);
      printf(argv[i]);
      printf("\n");
    }
    return 0;
  }
  

  ShowParams.vbs

  If Wscript.Arguments.Count = 0 Then
          Wscript.echo "No parameters found"
  Else
      i=0
          Do until i = Wscript.Arguments.Count
          Parms = Parms & "Param " & i & " = " & Wscript.Arguments(i) & " " & vbcr
          i = i+1
          loop
          Wscript.echo parms
  End If
  

  ShowParams.bat

  @echo off
  echo Param1 = %1
  echo Param2 = %2
  echo Param3 = %3
  

  *nix
  *nix handles command line arguments totally differently. On *nix, you launch a program using the execve API (or it's cousins execvp, execl, execlp, execle, and execvp). The interesting thing about these APIs is that they allow the caller to specify each of the command line arguments — the signature for execve is:

  int execve(const char *filename, char *const argv [], char *const envp[]);

  In *nix, the shell is responsible for turning the string provided by the user into the argv parameter to the program.

  Notes:
  On *nix, even though the execl() API allows you to specify a command line string, the execl() API parses that command line string into argv and argc before calling execve.

  References:
  •Microsoft Visual C++ Language Reference, "Parsing C++ Command-Line Arguments"
  http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
  •Larry Osterman's WebLog: The Windows command line is just a string
  http://blogs.msdn.com/larryosterman/archive/2007/10/03/the-windows-command-line-is-just-a-string.aspx

NumParams = %0%
Param1 = %1%
Param2 = %2%
Param3 = %3%
MsgBox NumParams = %0%
MsgBox Param1 = %1%
MsgBox Param2 = %2%
MsgBox Param3 = %3%

#NoTrayIcon              ;if you don't want a tray icon for this AutoHotkey program.
#NoEnv                   ;Recommended for performance and compatibility with future AutoHotkey releases.
#SingleInstance force    ;Skips the dialog box and replaces the old instance automatically
;;SendMode Input           ;I discovered this causes MouseMove to jump as if Speed was 0. (was Recommended for new scripts due to its superior speed and reliability.)
SetKeyDelay, 90          ;Any number you want (milliseconds)
CoordMode,Mouse,Screen   ;Initial state is Relative
CoordMode,Pixel,Screen   ;Initial state is Relative. Frustration awaits if you set Mouse to Screen and then use GetPixelColor because you forgot this line. There are separate ones for: Mouse, Pixel, ToolTip, Menu, Caret
MouseGetPos, xpos, ypos  ;Save initial position of mouse
WinGet, SavedWinId, ID, A     ;Save our current active window

;Set Up a Log File:
SetWorkingDir, %A_ScriptDir%  ;Set default directory to where this script file is located. (Note %% because it's expecting and unquoted string)
LogFile := "MyLog.txt"
FileAppend, This is a message`n, %LogFile%  ;Note the trailing (`n) to start a new line. This could instead be a leading (`n) if you want. (Note %% because it's expecting and unquoted string)

WinActivate ahk_id %SavedWinId%  ;Restore original window
MouseMove, xpos, ypos, 10    ;Restore original mouse position
ExitApp
Esc::ExitApp  ;Press ESC to cancel this script. Placed after the ExitApp.
              ;Note this is a hotkey definition (we're defining the ESC key to run ExitApp). A
              ;hotkey definition line stops execution at that point, so if you want the script
              ;to run to the end but have the ESC key available to terminate the script, put
              ;the hotkey definition at the end, just after your ExitApp statement.

n = Ishmael
x = Call me %n%
MsgBox %x%

x = 500
y = 500
z = 10
MouseMove, 500, 500, 10           ;works
MouseMove, 500 - 1, 500 + 1, 10   ;works
MouseMove,  x, y, z               ;works
MouseMove,  x - 1, y + 1, z + 2   ;works

;However, this doesn't work, because MouseMove
;doesn't expect an unquoted literal string
MouseMove, %x% - 1, %y% + 1, 10   ;doesn't work

MouseMove, %x%, %y%, %c%   ;works because "for backward compatibility, command parameters that are
                           ;documented as 'can be an expression' treat an isolated name in percent signs
                           ;(e.g. %Var%, but not Array%i%) as though the percent signs are absent."
                           ;        --AutoHotkey Documentation: Variables and Expressions

a = 500    ;a = "500"
b = 200    ;b = "200"
x := "a"
y := "b"
MouseMove, (%x%), (%y%)            ;x = a, a = 500.  y = b, b = 200
MouseGetPos, xpos, ypos
MsgBox xpos=%xpos%  ypos=%ypos%    ;xpos=500  ypos=200

MyDocument := "C:\Program Files\AutoHotkey\license.txt"
Run, notepad.exe "%MyDocument%"

Run, notepad.exe %MyDocument%

if (CreateProcess(NULL, command_line, NULL, NULL, FALSE, 0, NULL, aWorkingDir, &si, &pi))

v =
v := ""

ABC := "David"
David := "Susan"

v := "ABC"                      ; v = "ABC"
MsgBox v := "ABC"`n`nv = "%v%"

v := ABC                        ; ABC is a variable. v = "David"
MsgBox v := ABC`n`nv = "%v%"

v := %ABC%                      ; ABC is a variable containing the name of a variable. v = "Susan"
MsgBox v := `%ABC`%`n`nv="%v%"  ; NOTE: If ABC is undefined or blank, program halts!

v := "123"                      ; v = "123" (quotes NOT included)
MsgBox v := "123"`n`nv = "%v%"

v := 123                        ; v = "123" (If it can be interpreted as a number then it's a number, otherwise it's a variable name.)
MsgBox v := 123`n`nv = "%v%"

;123 can be made into a variable, as in this horrendous example:
123 := 456
MsgBox v = %123%  ; message is "v = 456"

ABC = David
David = Susan

v =  123                        ;v = "123"
MsgBox v = 123`n`nv = "%v%"

v = 0001                        ;v = "0001"
MsgBox v = 0001`n`nv = "%v%"

v = ABC                         ;v = "ABC"
MsgBox v = ABC`n`nv = "%v%"

v = %ABC%                       ;ABC is a variable. v = "David"
MsgBox v = `%ABC`%`n`nv = "%v%" (ABC = "David")

;PROBABLY NOT WHAT YOU WANTED:
v = "ABC"                       ;v = the literal string "ABC" (including double-quotes)
MsgBox v = "ABC"`n`nv = '%v%'

ABC := "David"
David := "Susan"

v := ABC                        ; ABC is a variable. v = "David"
MsgBox v := ABC`n`nv = "%v%"
v = %ABC%                       ; ABC is a variable. v = "David"
MsgBox v = `%ABC`%`n`nv = "%v%"

;PROBABLY NOT WHAT YOU WANTED:
v = ABC                         ; v = "ABC" (the literal string)
MsgBox v = ABC`n`nv = "%v%"
v := %ABC%                      ; ABC is a variable containing the name of a variable. v = "Susan"
MsgBox v := `%ABC`%`n`nv="%v%"  ; NOTE: If ABC is undefined, PROGRAM HALTS!
                                        (If David is undefined, then v = "")

SAT := "Saturday"          ;Another way to view this is:
Saturday := "Saturn"       ;  SAT --> Saturday --> Saturn
MON := "Monday"            ;  MON --> Monday --> Moon
Monday := "Moon"

MsgBox SAT := "Saturday"`nSaturday := "Saturn"`nMON := "Monday"`nMonday := "Moon"`n`n(another way to view this:)`nSAT --> Saturday --> Saturn`nMON --> Monday --> Moon`n`n#16

; =
If ("Saturday" = "Saturday")
  MsgBox ("Saturday" = "Saturday")
If ("Saturday" = "SATURDAY")
  MsgBox ("Saturday" = "SATURDAY")

; ==  (case sensitive compare)
If ("Saturday" == "Saturday")              ;== Case Sensitive
  MsgBox ("Saturday" == "Saturday")
If ("Saturday" == "SATURDAY")              ;== Case Sensitive
  MsgBox NO

;SAT = "Saturday"
If (SAT = "Saturday")       ;SAT = "Saturday", compare with "Saturday"
  MsgBox (SAT = "Saturday")
If ("Saturday" = SAT)       ;Reverse works the same
  MsgBox ("Saturday" = SAT)
If (SAT = "xxxxx")
  MsgBox NO
If ("xxxxx" = SAT)
  MsgBox NO

;%SAT% = "Saturn"
If ("Saturn" = "Saturn")
  MsgBox ("Saturn" = "Saturn")
If (%SAT% = "Saturn")  ;SAT = "Saturday", %SAT% = "Saturn", compare with "Saturn" (no problem if SAT not defined)
  MsgBox (`%SAT`% = "Saturn")`n`n(no problem if SAT not defined)
If ("Saturn" = %SAT%)  ;Reverse works the same (no problem if SAT not defined)
  MsgBox ("Saturn" = `%SAT`%)`n`n(no problem if SAT not defined)
If ("xxxxx" = %SAT%)   ;compare "xxxxx" with "Saturn"
  MsgBox NO
If (%SAT% = "xxxxx")   ;compare "Saturn" with "xxxxx"
  MsgBox NO

;"Moon" = %MON%
If ("Moon" = "Moon")
  MsgBox ("Moon" = "Moon")
If (%MON% = "Moon")    ;MON = "Monday", Monday = "Moon", compare with "Moon" (no problem if MON not defined)
  MsgBox (%MON% = "Moon")`n`nMON = "Monday", Monday = "Moon", compare with "Moon"`n`n(no problem if MON not defined)
If ("Moon" = %MON%)    ;"Moon", compare with MON = "Monday", Monday = "Moon" (no problem if MON not defined)
  MsgBox ("Moon" = `%MON`%)`n`n"Moon", compare with MON = "Monday", Monday = "Moon"`n`n(no problem if MON not defined)
If ("xxxxx" = %MON%)   ;compare "xxxxx" with "Moon"
  MsgBox NO
If (%MON% = "xxxxx")   ;compare "Moon" with "xxxxx"
  MsgBox NO

;SAT =? MON
If (SAT = MON)      ;Compare "Saturday" = "Monday" [SAT = "Saturday", MON = "Monday"]
  MsgBox NO
If (SAT < MON)      ;"Saturday" < "Moon"
  MsgBox NO
If (SAT > MON)      ;"Saturday" > "Moon"  [S > M]
  MsgBox (SAT > MON)`n`n"Saturday" > "Monday"`n`n[S > M]

;SAT =? %MON%
If (SAT = %MON%)    ;Compare "Saturday" = "Moon". [SAT = "Saturday", compare with MON = "Monday", Monday = "Moon"]
  MsgBox NO
If (SAT < %MON%)    ;"Saturday" < "Moon"
  MsgBox NO
If (SAT > %MON%)    ;"Saturday" > "Moon"  [S > M]
  MsgBox (SAT > `%MON`%)`n`n"Saturday" > "Moon"   [S > M]`n`nSAT = "%SAT%",`nMON = "%MON%", %MON% = "Moon"

;%SAT% =? MON
If (%SAT% = MON)    ;Compare "Saturn" = "Monday". [SAT = "Saturday", Saturday = "Saturn", MON = "Monday"]
  MsgBox NO
If (%SAT% < MON)    ;"Saturn" < "Monday"
  MsgBox NO
If (%SAT% > MON)    ;"Saturn" > "Monday"  [S > M]
  MsgBox (`%SAT`% > MON)`n`nSAT = "Saturday", %SAT% = "Saturn", compare with MON = "Monday"`n`n"Saturn" > "Moon"`n`n[S > M]

;%SAT% =? %MON%
If (%SAT% = %MON%)  ;Compare "Saturn" = "Moon". [SAT = "Saturday", Saturday = "Saturn", compare with MON = "Monday", Monday = "Moon"]
  MsgBox NO
If (%SAT% < %MON%)  ;"Saturn" < "Moon"
  MsgBox NO
If (%SAT% > %MON%)  ;"Saturn" > "Moon"  [S > M]
  MsgBox (`%SAT`% > `%MON`%)`n`nSAT = "Saturday", %SAT% = "Saturn", compare with`nMON = "Monday", %MON% = "Moon"`n`n"Saturn" > "Moon"`n`n[S > M]

;COMPARING NUMERIC VALUES VS. COMPARING STRINGS     if statements with ()
x = 05           ; x = "05"
if (x > 3.14)    ; (5 > 3.14) ?  Compare numeric values, since both can be interpreted as numeric values.
  MsgBox if (x > 3.14)`nwith x = "05"`n`nCompare numeric values, since both "05" and "3.14" can be interpreted as numbers.`n(5 > 3.14) ?`nyes
else
  MsgBox xxxxxx

if (x > "3.14")  ; ("05" > "3.14") ?  Compare strings, since "3.14" is explicitly a string. (The " " around 3.14 say it's a string, not a number, so do a string compare.)
  MsgBox xxxxxx
else
  MsgBox if (x > "3.14")`nwith x = "05"`n`nCompare strings, since "3.14" is explicitly a string.`nThe " " around "3.14" say it's a string, not a number, so do a string compare.`n("05" > "3.14") ?`n("0" > "3") ?`n(48 > 51) ?`nno


; ASCII table:
;   /  47
;   0  48
;   1  49
;   2  50
;   3  51
;   4  52
;   5  53
;   6  54
;   7  55
;   8  56
;   9  57
;   :  58
;DEREFERENCE TESTS
y := "x"

;Compare %y% with 3.14
x = 03             ; x = "03"
if (%y% > 3.14)    ; (3 > 3.14) ?
  MsgBox xxxxxx
else
  MsgBox if (`%y`% > 3.14)`nwith y = "x"`nand x = "03"`n`nCompare numeric values, since both "03" and "3.14" can be interpreted as numbers.`n(3 > 3.14) ?`nno

x = 05             ; x = "05"
if (%y% > 3.14)    ; (5 > 3.14) ?
  MsgBox if (`%y`% > 3.14)`nwith y = "x"`nand x = "05"`n`nCompare numeric values, since both "05" and "3.14" can be interpreted as numbers.`n(5 > 3.14) ?`nyes
else
  MsgBox NO

;Compare %y% with "3.14"
x = 03               ; x = "03"
if (%y% > "3.14")    ; ("03" > "3.14") ?
  MsgBox xxxxxx
else
  MsgBox if (`%y`% > "3.14")`nwith y = "x"`nand x = "03"`n`nCompare strings, since "3.14" is explicitly a string.`nThe " " around "3.14" say it's a string, not a number, so do a string compare.`n("03" > "3.14") ?`n("0" > "3") ?`n(48 > 51) ?`nno

x = 05               ; x = "05"
if (%y% > "3.14")    ; ("05" > "3.14") ?
  MsgBox xxxxxx
else
  MsgBox if (`%y`% > "3.14")`nwith y = "x"`nand x = "05"`n`nCompare strings, since "3.14" is explicitly a string.`nThe " " around "3.14" say it's a string, not a number, so do a string compare.`n("05" > "3.14") ?`n("0" > "3") ?`n(48 > 51) ?`nno

x := "/"             ; x = "/"
if (%y% > "3.14")    ; ("/" > "3.14") ?
  MsgBox xxxxxx
else
  MsgBox if (`%y`% > "3.14")`nwith y = "x"`nand x = "/"`n`nCompare strings, since "3.14" is explicitly a string.`nThe " " around "3.14" say it's a string, not a number, so do a string compare.`n("/" > "3.14") ?`n("/" > "3") ?`n(47 > 51) ?`nno

x := ":"             ; x = ":"
if (%y% > "3.14")    ; (":" > "3.14") ?
  MsgBox if (`%y`% > "3.14")`nwith y = "x"`nand x = ":"`n`nCompare strings, since "3.14" is explicitly a string.`nThe " " around "3.14" say it's a string, not a number, so do a string compare.`n(":" > "3.14") ?`n(":" > "3") ?`n(58 > 51) ?`nyes
else
  MsgBox xxxxxx

SAT := "Saturday"          ;Another way to view this is:
Saturday := "Saturn"       ;  SAT --> Saturday --> Saturn
MON := "Monday"            ;  MON --> Monday --> Moon
Monday := "Moon"

MsgBox SAT := "Saturday"`nSaturday := "Saturn"`nMON := "Monday"`nMonday := "Moon"`n`n(another way to view this:)`nSAT --> Saturday --> Saturn`nMON --> Monday --> Moon

;SAT
; If "Saturday" = .... illegal
If SAT = Saturday    ;SAT = "Saturday", compare with "Saturday"
  MsgBox If SAT = Saturday`n`nSaturday = Saturday
If SAT = %Saturday%  ;SAT = "Saturday", compare with %Saturday% = "Saturn"
  MsgBox NO
If SAT = SAT         ;SAT = "Saturday", compare with "SAT"
  MsgBox NO
If SAT = %SAT%       ;SAT = "Saturday", compare with %SAT% = "Saturday"
  MsgBox If SAT = `%SAT`%`n`nSaturday = Saturday

;%SAT%
;NOTE: if SAT is undefined or blank, program will halt!
If %SAT% = Saturn   ;SAT = "Saturday", Saturday = "Saturn", compare with "Saturn"
  MsgBox If `%SAT`% = Saturn`n`nSAT = "%SAT%", `%Saturday`% = %Saturday%, compare with "Saturn"`n`n(Note: if SAT is undefined or blank, program will halt!)
If %SAT% = xxxxx   ;SAT = "Saturday", Saturday = "Saturn", compare with "xxxxx"
  MsgBox NO

;Saturday
If Saturday = Saturn   ;Saturday = "Saturn", compare with "Saturn"
  MsgBox Saturday = Saturn`n`nSaturday="%Saturday%",compare with "Saturn"
If Saturday = xxxxx   ;Saturday = "Saturn", compare with "xxxxx"
  MsgBox NO

;%Saturday%
;NOTE: if SATURDAY is undefined or blank, program will halt!
If %Saturday% =       ;Saturday = "Saturn", Saturn = <nothing>, compare with <nothing>
  MsgBox If `%Saturday`% = `n`nSaturday=%Saturday%, Saturn=<nothing>, compare with <nothing>`n`n(NOTE: if SATURDAY is undefined or blank, program will halt!)
If %Saturday% = %Saturn%  ;Saturday = "Saturn", Saturn = <nothing>, compare with %Saturn% = <nothing> (<nothing> = <nothing>)
  MsgBox if `%Saturday`% = `%Saturn`%`n`nSaturday=%Saturday%, Saturn=<nothing>`ncompare with`%Saturn`% = <nothing>`n`n<nothing>=<nothing>
If %Saturday% = xxxxx ;Saturday = "Saturn", Saturn = <nothing>, compare with "xxxxx"
  MsgBox NO
If %Saturday% = ""    ;Saturday = "Saturn", Saturn = <nothing>, compare with literal two double-quotes (a string containing two characters, both double-quotes)
  MsgBox NO

I2:
;COMPARING NUMERIC VALUES VS. COMPARING STRINGS     if statements without ()
; ASCII table:
;   !  33
;   "  34
;   #  35
;   0  48

x = 03            ; x = "03"
if x > 3.14       ; 3 > 3.14  (Compare numeric values, since both can be interpreted as numeric values)
  MsgBox xxxxxx
else
  MsgBox if x > 3.14`nwith x=%x%`n`nCompare numeric values, since both can be interpreted as numeric values`n3 > 3.14 ?`nno

x = 05            ; x = "05"
if x > 3.14       ; 5 > 3.14  (Compare numeric values, since both can be interpreted as numeric values)
  MsgBox if x > 3.14`nwith x=%x%`n`nCompare numeric values, since both can be interpreted as numeric values`n5 > 3.14 ?`nyes
else
  MsgBox xxxxxx

x = 03            ; x = "03"
if x > "3.14"     ; compare string '03' with string '"3.14"' (double quotes are part of the string). Compare ascii 0 in 03 with leading quotation mark in "3.14" (48 > 34 ?) Yes.
  MsgBox if x > "3.14"`nwith x=%x%`n`nDouble quotes are part of the string "3.14"`nso string compare 03 with "3.14"`ncompare leading '0' in 03 with leading quotation mark in "3.14"`nascii(0) = 48`nascii(") = 34`n48 > 34 (?)`nyes
else
  MsgBox xxxxxx

x = !             ; x = '!' (ascii 33)
if x > "3.14"     ;compare string '!' with string '"3.14"' (double quotes are part of the string). Compare ascii ! with leading quotation mark in "3.14" (48 > 34 ?) Yes.
; (! > ")?  --> (33 > 34) ? no
  MsgBox xxxxxx
else
 MsgBox if x > "3.14"`nwith x=%x%`nno`n`ncompare ascii ! with leading quotation mark in "3.14"`nascii(!) = 33`nascii(") = 34`n(33 > 34)?`nno

x = #             ; x = '#' (ascii 35)
if x > "3.14"     ; (! > ")?  --> (35 > 34) ? yes
  MsgBox if x > "3.14"`nwith x=%x%`nyes`n`ncompare ascii # with leading quotation mark in "3.14"`nascii(#) = 35`nascii(") = 34`n(35 > 34)?`nyes
else
  MsgBox xxxxxx


; ASCII table:
;   !  33
;   "  34
;   #  35
;   0  48
;DEREFERENCE TESTS
y := "x"

;compare %y% with 3.14
x = 03            ; x = "03"
if %y% > 3.14     ; 3 > 3.14 (?)
  MsgBox xxxxxx
else
  MsgBox if `%y`% > 3.14`nwith y := "x"`nand x = "03"`n`nCompare numeric values, since both "03" and "3.14" can be interpreted as numbers.`n3 > 3.14 (?)`nno

x = 05            ; x = "05"
if %y% > 3.14     ; 5 > 3.14 (?)
  MsgBox if `%y`% > 3.14`nwith y := "x"`nand x = "05"`n`nCompare numeric values, since both "05" and "3.14" can be interpreted as numbers.`n5 > 3.14 (?)`nyes
else
  MsgBox xxxxxx


;compare %y% with "3.14"
x = 03            ; x = "03"
if %y% > "3.14"   ; Double quotes are part of the string "3.14" so string compare '03' with string '"3.14"'. Compare ascii 0 in 03 with leading quotation mark in "3.14" (48 > 34 ?) Yes.
  MsgBox if `%y`% > "3.14"`nwith y := "x"`nand x=%x%`n`nDouble quotes are part of the string "3.14"`nso string compare 03 with "3.14"`ncompare leading '0' in 03 with leading quotation mark in "3.14"`nascii(0) = 48`nascii(") = 34`n48 > 34 (?)`nyes
else
  MsgBox xxxxxx

x = !             ; x = '!' (ascii 33)
if x > "3.14"     ;Double quotes are part of the string "3.14" so string compare '!' with string '"3.14"'. Compare '!' with leading quotation mark in "3.14" (48 > 34 ?) Yes.
  MsgBox xxxxxx
else
  MsgBox if `%y`% > "3.14"`nwith y := "x"`nand x=%x%`n`nDouble quotes are part of the string "3.14"`nso string compare ! with "3.14"`ncompare '!' with leading quotation mark in "3.14"`nascii(!) = 33`nascii(") = 34`n33 > 34 (?)`nno

x = #             ; x = '#' (ascii 35)
if x > "3.14"     ; (! > ")?  --> (35 > 34) ? yes
  MsgBox if `%y`% > "3.14"`nwith y := "x"`nand x=%x%`n`nDouble quotes are part of the string "3.14"`nso string compare # with "3.14"`ncompare '#' with leading quotation mark in "3.14"`nascii(#) = 35`nascii(") = 34`n35 > 34 (?)`nyes
else
  MsgBox xxxxxx

v := ""

If v =
  MsgBox v = ""

If (v = "")
  MsgBox v = ""

;Trim whitespace at the START of a string:
v := "     0001     "
MsgBox v="%v%"
v := RegExReplace( v, "\A\s+" )
MsgBox v="%v%"                  ;v = "0001     "

;Trim whitespace at the END of a string:
v := "     0001     "
MsgBox v="%v%"
v := RegExReplace( v, "\s+\z" )
MsgBox v="%v%"                  ;v = "     0001"

;Trim whitespace at the START AND END of a string:
v := "     0001     "
MsgBox v="%v%"
v := RegExReplace( v, "(^\s+)|(\s+$)")
MsgBox v="%v%"                  ;v = "0001"

;Trim whitespace at the START AND END of the string:
v := "     0001     "
MsgBox v="%v%"
v = %v%                         ;v = "0001" (AutoTrim ON by default)
MsgBox v="%v%"

;CONCATENATE TWO STRINGS TOGETHER
SAT := "Saturday"
MON := "Monday"
Saturday := "Saturn"
Monday := "Moon"


; using =
v = %SAT%%MON%      ; v = "SaturdayMonday"
MsgBox v = "%v%"


; using :=
v := "Saturday" . "Monday"  ; v = "SaturdayMonday"
MsgBox v = "%v%"

v := SAT . MON      ; v = "SaturdayMonday" (there must be a SPACE before and after dot)
MsgBox v = "%v%"

v := %SAT% . MON    ; v = "SaturnMonday"
MsgBox v = "%v%"

v := SAT . %MON%    ; v = "SaturdayMoon"
MsgBox v = "%v%"

v := %SAT% . %MON%  ; v = "SaturnMoon"
MsgBox v = "%v%"

Msgbox Var = %Var%
; OR
Msgbox % "Var = " . Var
;  string-^^^^^^  | ^^^-variable name
;           Concatenate

;Adding numbers together
v := "123"
v += 1
MsgBox v = "%v%"     ; v <- "124"

v := "123"
v := v + 1
MsgBox v = "%v%"     ; v <- "124"

;PROBABLY NOT WHAT YOU WANTED:
v = 123            ; v <- "123" (the literal string)
v = v + 1          ; v <- "v + 1" (the literal string)
MsgBox v = "%v%"

;Adding two strings together
;when both can be interpreted as integers, gives the resulting integer (as a string)
v1 := 123
v2 := 456
v := v1 + v2       ; v <- "579"
MsgBox v = "%v%"

;when one or both can be interpreted as float, gives the resulting float (as a string)
v1 := 1.23
v2 := 45.6
v := v1 + v2       ; v <- "46.830000"
MsgBox v = "%v%"

;When one or both can NOT be interpreted as a number, result is an empty string
v1 := "123"
v2 := "Susan"
v := v1 + v2       ; v <- "" (empty string)
MsgBox v = "%v%"

;Remove leading zeros from a number
v := 0001             ;v = "0001"
v += 0                ;v converted to integer, add zero, convert back to string
MsgBox v = "%v%"      ;v = "1" (the literal string "1"

;Remove leading blanks and trailing blanks from a number
v := "     1     "
MsgBox v = "%v%"      ;v = "     1     "
v += 0                ;v converted to integer, add zero, convert back to string
MsgBox v = "%v%"      ;v = "1" (the literal string "1"

;Remove leading and trailing blanks and leading zeros from a number
v := "     0001     "
MsgBox v = "%v%"      ;v = "     0001     "
v += 0                ;v converted to integer, add zero, convert back to string
MsgBox v = "%v%"      ;v = "1" (the literal string "1"

;(yea it's all the same. Just do v += 0)

;PAD A NUMBER WITH LEADING ZEROS OR SPACES — Method #1: SUBSTR
; Documentation on SubStr: "If StartingPos is less than 1, it is
; considered to be an offset from the end of the string. For example, 0
; extracts the last character and -1 extracts the two last characters."
v := 123
            ;....v....1                   ....v....1
v := SubStr("0000000000" . v, -9)  ; v = "0000000123"
MsgBox v = "%v%"

v := SubStr("abcdefghij" . v, -9)  ; v = "defghij123"  (easier to see what's happening)
MsgBox v = "%v%"

;PAD A NUMBER WITH LEADING ZEROS OR SPACES — Method #2: StringRight
v := 123
     ;....v....1              ....v....1...
v := "0000000000" . v  ; v = "0000000000123"  ( or could use v = "0000000000"%v% )
StringRight, v, v, 10  ; v =    "0000000123"
MsgBox v = "%v%"

;PAD A NUMBER WITH LEADING ZEROS OR SPACES — Method #3: sprintf()
StrIn := "1234"
size := VarSetCapacity(StrOut, 8)  ;want StrOut to hold 8 digits

;pad with zeros
DllCall("msvcrt\sprintf", Str, StrOut, Str, "%08d", "Int", StrIn )  ;pad with zeros
MsgBox, 0, Zeros, size=%size%`nStrIn = %StrIn%`nStrOut = %StrOut%   ;StrOut = "00000123"

;pad with blanks
DllCall("msvcrt\sprintf", Str, StrOut, Str,  "%8d", "Int", StrIn )  ;pad with blanks
MsgBox, 0, Spaces, size=%size%`nStrIn = %StrIn%`nStrOut = %StrOut%  ;StrOut = "     123"

;PAD A NUMBER WITH LEADING ZEROS OR SPACES — Method #4: Prepend leading zeros
v = 123
Loop, % 9-StrLen(v)            ; (9 for 9 digits total)
    v = 0%v%                   ; OR: v := 0 . v
MsgBox, 0, Zeros, v = "%v%"    ; v = "000000123"

;Prepend leading spaces
v = 123
Loop, % 9-StrLen(v)            ; (9 for 9 digits & spaces total)
    v := A_Space . v         ; OR: v := " " . v
MsgBox, 0, Spaces, v = "%v%"   ; v = "      123"

;PAD A NUMBER WITH LEADING ZEROS OR SPACES — Method #5: Using SetFormat
;(Note: Be wary of converting an integer to a float and back to an integer.
; An integer has 32 bits of data, whereas a float has only 27 bits of data.)
v = 1234
SetFormat, Float, 08.0 ; (08 for zero padded 8 digits total, .0 for zero decimal places)
v += 0.0               ; v converted to float, add zero, convert back to string
MsgBox v = %v%         ; v = '00001234'

v = 1234
SetFormat, Float, 8.0  ; (8 for space padded 8 digits & spaces total, .0 for zero decimal places)
v += 0.0               ; v converted to float, add zero, convert back to string
MsgBox v = %v%         ; v = '    1234'

;Set/Show Working Directory
SetWorkingDir,%A_ScriptDir%
MsgBox A_WorkingDir=%A_WorkingDir%

;Creating a File  (note: directory must exist)
FileAppend, test 10, MyFile10.log           ;<WorkingDir>\MyFile10.log
FileAppend, test 11, \MyFile11.log          ;C:\MyFile11.log
FileAppend, test 12, SubDir\MyFile12.log    ;<WorkingDir>\SubDir\MyFile12.log
FileAppend, test 13, SubDir\\\\\\\\\\\\\MyFile13.log   ;<WorkingDir>\SubDir\MyFile13.log Doesn't seem to matter how many extra \
V := "C:\TEMP"
FileAppend, test 14, %V%MyFile14.log        ;C:\TEMPMyFile14.log
FileAppend, test 15, %V%\MyFile15.log       ;C:\TEMP\MyFile15.log
FileAppend, test 16, %V%\\\\\\\\\\\MyFile16.log   ;C:\TEMP\MyFile16.log  Doesn't seem to matter how many extra \
FileAppend, test 17, ..\MyFile17.log        ;Up one directory from WorkingDir. <WorkingDir-^>\MyFile17.log
MsgBox ErrorLevel=%ErrorLevel%              ;FileAppend test for error. 0=SUCCESS, 1=FAIL

• Email
• Uri
• Numbers
• Strings
• Dates and Times
• Misc
• Address/Phone
• Markup/Code

• Grabbing HTML Tags
• Trimming Whitespace
• Matching an IP address
• Matching a Floating Point Number
• Matching an Email Address
• Matching Valid Dates
• Finding or Verifying Credit Card Numbers
• Matching Complete Lines
• Removing Duplicate Lines or Items
• Regex Examples for Processing Source Code
• Two Words Near Each Other

• Ensure that a path doesn't end with a backslash
• Ensure that a path ends with a backslash
• Replace characters illegal in a file name by something else (can be empty)
• Keep only lines starting with a given string
• Parse a date
• trim chars on left and/or right of strings
• How to make parsing loops work from back to front?
• How to replace variable references in a template text file by the value of the referenced variables?
• How to replace i with I only if it has spaces before and after
• remove duplicate lines

000..255:       ——  ^([01][0-9][0-9]|2[0-4][0-9]|25[0-5])$
0 or 000..255:  ——  ^([01]?[0-9]?[0-9]|2[0-4][0-9]|25[0-5])$
0 or 000..127:  ——  ^(0?[0-9]?[0-9]|1[0-1][0-9]|12[0-7])$
0..999:         ——  ^([0-9]|[1-9][0-9]|[1-9][0-9][0-9])$
000..999:       ——  ^[0-9]{3}$
0 or 000..999:  ——  ^[0-9]{1,3}$
1..999:         ——  ^([1-9]|[1-9][0-9]|[1-9][0-9][0-9])$
001..999:       ——  ^(00[1-9]|0[1-9][0-9]|[1-9][0-9][0-9])$
1 or 001..999:  ——  ^(0{0,2}[1-9]|0?[1-9][0-9]|[1-9][0-9][0-9])$
0 or 00..59:    ——  ^[0-5]?[0-9]$
0 or 000..366:  ——  ^(0?[0-9]?[0-9]|[1-2][0-9][0-9]|3[0-6][0-9]|36[0-6])$

    1. elvis                 Find elvis
    2. \belvis\b             Find elvis as a whole word
    3. \belvis\b.*\balive\b  Find text with "elvis" followed by "alive"
    4. \b\d\d\d-\d\d\d\d     Find seven-digit phone number
    5. \b\d{3}-\d{4}         Find seven-digit phone number a better way
    6. \ba\w*\b              Find words that start with the letter a
    7. \d+                   Find repeated strings of digits
    8. \b\w{6}\b             Find six letter words
    9. .^\d{3}-\d{4}$        Validate a seven-digit phone number
   10. \b\w{5,6}\b           Find all five and six letter words
   11. \b\d{3}\s\d{3}-\d{4}  Find ten digit phone numbers
   12. \d{3}-\d{2}-\d{4}     Social security number
   13. ^\w*                  The first word in the line or in the text
   14. \(?\d{3}[) ]\s?\d{3}[- ]\d{4}  A ten digit phone number
   15. \S+                   All strings that do not contain whitespace characters
   16. \b\d{5}-\d{4}\b|\b\d{5}\b           Five and nine digit Zip Codes
   17. (\(\d{3}\)|\d{3})\s?\d{3}[- ]\d{4}  Ten digit phone numbers, a better way.
                                           This expression will find phone numbers in several formats, like
                                           "(800) 325-3535" or "650 555 1212".
                                           The "\(?" searches for zero or one left parentheses,
                                           "[) ]" searches for a right parenthesis or a space. The
                                           "\s?" searches for zero or one whitespace characters.
                                           Unfortunately, it will also find cases like
                                           "650) 555-1212" in which the parenthesis is not balanced.
                                           Below, you'll see how to use alternatives to eliminate this problem.
   18. (\d{1,3}\.){3}\d{1,3}               A simple IP address finder
   19. ((2[0-4]\d|25[0-5]|[01]?\d\d?)\.){3}(2[0-4]\d|25[0-5]|[01]?\d\d?)  IP finder
   20. \b(\w+)\b\s*\1\b      Find repeated words
   21. \b(?<Word>\w+)\b\s*\k<Word>\b   Capture repeated word in a named group
   22. \b\w+(?=ing\b)        The beginning of words ending with "ing"
   23. (?<=\bre)\w+\b        The end of words starting with "re"
   24. (?<=\d)\d{3}\b        Three digits at the end of a word, preceded by a digit
   25. (?<=\s)\w+(?=\s)      Alphanumeric strings bounded by whitespace
   26. \b\w*q[^u]\w*\b       Words with "q" followed by NOT "u"
   27. \b\w*q(?!u)\w*\b      Search for words with "q" not followed by "u"
   28. \d{3}(?!\d)           Three digits not followed by another digit
   29. (?<![a-z ])\w{7}      Strings of 7 alphanumerics not preceded by a letter or space
   30. (?<=<(\w+)>).*(?=<\/\1>)  Text between HTML tags
   31. Text between HTML tags (see referenced source page above)
   32. a.*b                  The longest string starting with a and ending with b
   33. a.*?b                 The shortest string starting with a and ending with b

    a. \(\d\d\d\)\s\d\d\d-\d\d\d\d
    b. \(\d{3}\)\s\d{3}-\d{4}
    4. \b\d\d\d-\d\d\d\d     Find seven-digit phone number
    5. \b\d{3}-\d{4}         Find seven-digit phone number a better way
    9. .^\d{3}-\d{4}$        Validate a seven-digit phone number
   11. \b\d{3}\s\d{3}-\d{4}  Find ten digit phone numbers
   14. \(?\d{3}[) ]\s?\d{3}[- ]\d{4}  A ten digit phone number
   17. (\(\d{3}\)|\d{3})\s?\d{3}[- ]\d{4}  Ten digit phone numbers, a better way.

    a. (\d\d)-(\d\d)-(\d\d\d\d)    MM-DD-YYYY   (MM -& $1, DD -& $2, YYY -& $3)
    b. (\d\d\d\d)-(\d\d)-(\d\d)    YYYY-MM-DD   (YYYY -& $1, MM -& $2, DD -& $3)
    c. ^\d{1,2}\/\d{1,2}\/\d{4}$   XX/XX/YYYY where XX can be 1 or 2 digits long and YYYY is always 4 digits long.

; Examples
f1 := RegExReplace("55555", "5", "five") ;f1 = "fivefivefivefivefive"
MsgBox f1=%f1%

f2 := RegExReplace("55555", "55", "x") ;f2 = "xx5"
MsgBox f2=%f2%

;Regular Expression to EXTRACT Month, Day, Year, from 1/22/2009
;month & day can be 1 or 2 digits
 c := "xxxxxxxx 1/22/2009 yyyyyyyyyyyy"
 month := RegExReplace(c,".*?(\d{1,2})\/(\d{1,2})\/(\d{4})(.*)","$1")
 day   := RegExReplace(c,".*?(\d{1,2})\/(\d{1,2})\/(\d{4})(.*)","$2")
 year  := RegExReplace(c,".*?(\d{1,2})\/(\d{1,2})\/(\d{4})(.*)","$3")
 MsgBox month=%month%`nday=%day%`nyear=%year%

;An example of how we can step by step build up our Regular Expression
;Given string c, extract the data...
c := "  02-17-2009     238  Payment by Check.     314.15   9,265.35  "

;Trim leading and trailing spaces
c = %c%

; 1.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Start with "(.*)" which grabs the whole string
f3 := RegExReplace(c, "(.*)", "$1")
MsgBox f3=%f3%
; f3 = "02-17-2009     238  Payment by Check.     314.15   9,265.35"

; 2.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add "(\d\d)" to parse off the first two digits (the month)
f4 := RegExReplace(c, "(\d\d)(.*)", "{$1} {$2}")
MsgBox f4=%f4%
; f4 = "{02} {-17-2009     238  Payment by Check.     314.15   9,265.35}"

; 3.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add "-" to parse off the dash
f5 := RegExReplace(c, "(\d\d)-(.*)", "{$1} {$2}")
MsgBox f5=%f5%
; f5 = "{02} {17-2009     238  Payment by Check.     314.15   9,265.35}"

; 4.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add "(\d\d)" to parse off the second two digits (the day) and save it as $2
f6 := RegExReplace(c, "(\d\d)-(\d\d)(.*)", "{$1} {$2} {$3}")
MsgBox f6=%f6%
; f6 = "{02} {17} {-2009     238  Payment by Check.     314.15   9,265.35}"

; 5.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add "-" to parse off the dash
f6 := RegExReplace(c, "(\d\d)-(\d\d)(.*)", "{$1} {$2} {$3}")
MsgBox f6=%f6%
; f6 = "{02} {17} {-2009     238  Payment by Check.     314.15   9,265.35}"

; 6.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add "(\d\d\d\d)" to parse off the year (4 digits) and save it as $3
f7 := RegExReplace(c, "(\d\d)-(\d\d)-(\d\d\d\d)(.*)", "{$1} {$2} {$3} {$4}")
MsgBox f7=%f7%
; f7 = "{02} {17} {2009} {     238  Payment by Check.     314.15   9,265.35}"

; 7.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add " +" to parse off one or more spaces
f8 := RegExReplace(c, "(\d\d)-(\d\d)-(\d\d\d\d) +(.*)", "{$1} {$2} {$3} {$4}")
MsgBox f8=%f8%
; f8 = "{02} {17} {2009} {238  Payment by Check.     314.15   9,265.35}"

; 8.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add "(\d+)" to parse off the check number (one or more digits) and save it as $4
f9 := RegExReplace(c, "(\d\d)-(\d\d)-(\d\d\d\d) +(\d+)(.*)", "{$1} {$2} {$3} {$4} {$5}")
MsgBox f9=%f9%
; f9 = "{02} {17} {2009} {238} {  Payment by Check.     314.15   9,265.35}"

; 9.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add " +" to parse off one or more spaces
f10 := RegExReplace(c, "(\d\d)-(\d\d)-(\d\d\d\d) +(\d+) +(.*)", "{$1} {$2} {$3} {$4} {$5}")
MsgBox f10=%f10%
;f10 = "{02} {17} {2009} {238} {Payment by Check.     314.15   9,265.35}"

; 10.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add "(.*?)" to parse off the text (minimal match), followed by " {5}" to parse off 5 spaces
; (there apparently is always 5 spaces. This tells us when we're done parsing off the text.)
f11 := RegExReplace(c, "(\d\d)-(\d\d)-(\d\d\d\d) +(\d+) +(.*?) {5}(.*)", "{$1} {$2} {$3} {$4} {$5} {$6}")
MsgBox f11=%f11%
; f11 = "{02} {17} {2009} {238} {Payment by Check.} {314.15   9,265.35}"

; 11.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add "([\d,.]+)" to parse off the dollars and cents (one or more digits with possible commas and decimal point, e.g. 27,182.81)
f12 := RegExReplace(c, "(\d\d)-(\d\d)-(\d\d\d\d) +(\d+) +(.*?) {5}([\d,.]+)(.*)", "{$1} {$2} {$3} {$4} {$5} {$6} {$7}")
MsgBox f12=%f12%
; f12 = "{02} {17} {2009} {238} {Payment by Check.} {314.15} {   9,265.35}"

; 12.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add " {3}" to parse off 3 spaces (apparently always 3)
f13 := RegExReplace(c, "(\d\d)-(\d\d)-(\d\d\d\d) +(\d+) +(.*?) {5}([\d,.]+) {3}(.*)", "{$1} {$2} {$3} {$4} {$5} {$6} {$7}")
MsgBox f13=%f13%  ;f13 = "{02} {17} {2009} {238} {Payment by Check.} {314.15} {9,265.35}"

; 13.
; c := "02-17-2009     238  Payment by Check.     314.15   9,265.35"
; Add "([\d,.]+" to parse off the dollars and cents (one or more digits with possible commas and decimal point, e.g. 27,182.81)
f14 := RegExReplace(c, "(\d\d)-(\d\d)-(\d\d\d\d) +(\d+) +(.*?) {5}([\d,.]+) {3}([\d,.]+)(.*)", "{$1} {$2} {$3} {$4} {$5} {$6} {$7} {$8}")
MsgBox f14=%f14%
; f14 = "{02} {17} {2009} {238} {Payment by Check.} {314.15} {9,265.35} {}"
;        (the last empty {} indicates there's nothing left over)

;find the $ dollar sign
c := "xxx $17.25 yyy"
dollar := RegExReplace(c,"(.*?)(\$)(.*)","$2")
MsgBox dollar=%dollar%

;extract price and add a dollar sign
c := "xxx 17.25 yyy"
price := RegExReplace(c,"(.*?)([\d,.]+)(.*)","$$$2")
msgbox price=%price%   ; price = "$17.25"

; For RegExReplace replace string only:
;    To specify a literal $, use $$
;    $ is the only character that needs such special treatment in a RegEx replace string.
;    Backslashes are never needed to escape anything else in a RegEx replace string.
; (RegEx search string still needs to have many characters escaped.)

NOTE:	ALL VARIABLES ARE STORED AS CHARACTER STRINGS !!! Strings containing numbers are converted to numbers when needed, and the result is converted back to a string.
/******************************************************************************
NOTE:	Closing */ must be first thing on line. Otherwise you'll be asking yourself, "Why does my script stop running at this point, as if the whole rest of the script was commented out?" MsgBox Hello /* here is a comment and another comment */ MsgBox Goodbye ;You'll never see this message MsgBox Hello /* here is a comment and another comment */ MsgBox Goodbye ;Now you're OK
/******************************************************************************
NOTE:	Space here ruins function call ↓ MyFunc (Param1) MyFunc(Param1)

• When sending text, if there are problems, sometimes it helps to throw in a short delay (Sleep 100), or to slow down the sending of characters by using SetKeyDelay (e.g. SetKeyDelay 90)
  
  
• MsgBox: You may need to manually restore focus to your current window after a call to MsgBox. I was debugging an AutoHotkey script by throwing in a bunch of MsgBox messages, and I discovered a problem that focus wasn't being returned to my window after the MsgBox timed out. So, I added a WinActivate after MsgBox to restore focus to my window, and all was well again.
  (May have been caused by cross contamination from another unrelated program. I'm so tired of debugging Windows programs only to discover there's nothing wrong with the program I'm debugging, it's the Windows OS itself that's been corrupted by a completely unrelated program. I thought those days were long behind us.)
  Update: I had another case where this fix was exactly the wrong thing to do. The "current window" wasn't the one I wanted. Removing the WinExist/WinActivate combo fixed the problem. (Alas, no solution is universal.)

;Example 1. Log a message
SetWorkingDir, %A_ScriptDir%  ;Set default directory to where this script file is located
LogFile := "MyLog.txt"
FileAppend, This is a message`n, %LogFile%  ;(note the trailing (`n) to start a new line. This could instead be a leading (`n) if you want.

;Example 2. Include a time stamp
SetWorkingDir, %A_ScriptDir%  ;Set default directory to where this script file is located
LogFile := "MyLog.txt"
FormatTime, TimeString, , yyyy-MM-dd hh:mm:ss tt
FileAppend, `n%TimeString% : This is a message`n, %LogFile%

;Example 3. Put it all in a function named LogMsg
SetWorkingDir, %A_ScriptDir%  ;Set default directory to where this script file is located
LogFile := "MyLog.txt"
LogMsg("This is a message")   ;Note LogMsg adds a leading (`n) so each message starts on a new line
LogMsg("Variable X = " . X )  ;Concatenate using the dot .
ExitApp

;---------------------------
;And here is our function:
LogMsg( msg )
{
  global LogFile
  FormatTime, TimeString, , yyyy-MM-dd hh:mm:ss tt
  FileAppend, `n%TimeString% : %msg%, %LogFile%
}

/******************************************************************************
Capturing a screen image during run using IrfanView (www.irfanview.com)
*/
RunWait "C:\Program Files\IrfanView\i_view32.exe" "/capture=1  /convert=C:\TEMP\MyImage.bmp"

• Laptop Low Battery Alert (BatteryDeley): http://www.autohotkey.com/forum/viewtopic.php?t=40683
• Laptop Battery Indicator (PowerCircle): http://powercircle.aldwin.us/
• Laptop Battery Indicator (PowerMeter+): http://mattcollinge.wordpress.com/software/power-meter-plus/
• System Uptime: http://www.autohotkey.com/forum/topic18534.html
• DimScreen: http://www.donationcoder.com/Software/Skrommel/#DimScreen
• Extract Informations about TaskButtons http://www.autohotkey.com/forum/viewtopic.php?t=18652
• Extra mouse button does left click & hold (one line script)

  XButton2::click down
  

• AUTOHOTKEY:
  • VarExist(Var) - http://www.autohotkey.com/forum/viewtopic.php?p=83371#83371
  • ƒ() - Pass an array of integers to a function. http://www.autohotkey.com/forum/viewtopic.php?p=242750#242750
• STRINGS:
  • SetWidth(Str,Width,AlignText) - increase a string's length by adding spaces to it and aligns it Left/Center/Right.
  • NumFormat( Number, Width, Dec, PadChar ) - format a float. Pad leading characters (any character) to a numeric string.
  • Replicate(chr,x)
    Replicate(chr(196),80) - creates a horizontal ruling 80 characters wide
  • Space(Width)
    Space(80) - 80 spaces
  • UPPER(String)
  • LOWER(String)
  • PROPER(String)
  http://www.autohotkey.com/forum/viewtopic.php?p=53028#53028
  • RandStr() - Generates and returns a Random string. http://www.autohotkey.com/forum/viewtopic.php?p=217712#217712
  • HashStr() - Hashes a String and returns value as hex.
  • Hash() - Hashes a Byte-array and returns value as hex.
  • http://www.autohotkey.com/forum/viewtopic.php?p=231784#231784
  • Last Day Of Month (e.g. 30, 31, 28, 29) LDOM() - http://www.autohotkey.com/forum/viewtopic.php?p=54502#54502
    - YearMonthDay format - http://www.autohotkey.com/forum/viewtopic.php?p=54532#54532
• COLOR:
  • HEX2RGB(HEXString,Delimiter="")
  • RGB2HEX(RGBString,Delimiter="")
  • CheckHexC(HEXString) - validates a "Hex Color Code" by calling the above two functions.
    Examples:
    HEX2RGB("FFFFFF") -> "255,255,255"
    RGB2HEX("255,255,255") -> "FFFFFF"
    CheckHexC("FFFFFF") -> 1
    CheckHexC("GOYYAH") -> 0
  http://www.autohotkey.com/forum/viewtopic.php?p=58125#58125
  
  
  • ChooseColor() - wrapper function for windows ChooseColor Dialog. http://www.autohotkey.com/forum/viewtopic.php?p=103432#103432
  • ColorAdjL() - Adjust Luminance for a given RGB color. In other words, this function can derive a lighter / darker shade for a given RGB color. http://www.autohotkey.com/forum/viewtopic.php?p=238242#238242
  • GetSysColor() - calls windows GetSysColor function http://www.autohotkey.com/forum/viewtopic.php?p=66521#66521
  • windows GetSysColor function: http://msdn.microsoft.com/en-us/library/ms724371.aspx
• FILES:
  • GetShortPathName(LongPath)
    using %A_LoopFileShortPath% - http://www.autohotkey.com/forum/viewtopic.php?p=69345#69345
    using DllCall - http://www.autohotkey.com/forum/viewtopic.php?p=69366#69366
  • GetFileFolderSize(fPath) - http://www.autohotkey.com/forum/viewtopic.php?p=82689#82689
  • DriveSpace() - Returns the FreeSpace / Capacity of a Drive in bytes. http://www.autohotkey.com/forum/viewtopic.php?p=92483#92483
  • ShellFileOperation() - Basic Wrapper. A shell function that can be called to Copy / Move / Delete / Rename File(s). http://www.autohotkey.com/forum/viewtopic.php?p=133249#133249
  • GetBinaryType() - Determines whether a file is executable, and if so, what type of executable file it is. http://www.autohotkey.com/forum/viewtopic.php?p=66383#66383
  • FileGetVersionInfo() - Extracts and returns version information from an executable file. http://www.autohotkey.com/forum/viewtopic.php?p=233188#233188
• SOUND:
  • SoundCard() - Returns the number of soundcards available on a system. http://www.autohotkey.com/forum/viewtopic.php?p=88891#88891
  • SoundExC() - SoundEx Classic Version. Phonetic algorithm for indexing names by sound (English). http://www.autohotkey.com/forum/viewtopic.php?p=240065#240065
• IMAGES:
  • ConvertGraphicsFile() - Converts image file format between GIF/BMP/JPG/PNG. http://www.autohotkey.com/forum/viewtopic.php?p=190227#190227
• VIDEO:
  • AviFileInfo() - Returns the video properties of an AVI file http://www.autohotkey.com/forum/viewtopic.php?p=91036#91036
• SYSTEM:
  • GetPriority(ProcessName) - http://www.autohotkey.com/forum/viewtopic.php?p=80548#80548
  • ProcessOwner() - Returns the Owner for a given Process ID. http://www.autohotkey.com/forum/viewtopic.php?p=232445#232445
  • ProcessCreationTime( ProcessID ) - http://www.autohotkey.com/forum/viewtopic.php?p=97186#97186
  • Affinity_Set() - Sets the CPU to be used in Dual/Quad/Multi core processors / Effectively, this function allows you to choose which AHK script uses what processor. http://www.autohotkey.com/forum/viewtopic.php?p=202460#202460

• Basic Functions
  • TXT_TotalLines
  • TXT_ReadLines
  • TXT_Tail
• Alignment Functions
  • TXT_AlignLeft
  • TXT_AlignCenter
  • TXT_AlignRight
  • TXT_ReverseLines
• Removement Functions
  • TXT_RemoveLines
  • TXT_RemoveBlankLines
  • TXT_RemoveDuplicateLines
• Replacement Functions
  • TXT_Replace
  • TXT_RegExReplace
  • TXT_ReplaceLine
• Insertion Functions
  • TXT_LineNumber
  • TXT_InsertLine
  • TXT_InsertPrefix
  • TXT_InsertSuffix
• Column Functions
  • TXT_ColGet
  • TXT_ColPut
  • TXT_ColCut
• Trimming Functions
  • TXT_TrimLeft
  • TXT_TrimRight
• CSV Functions
  • TXT_GetCSV
  • TXT_SetCSV
• File Join/Split Functions
  • TXT_ConCat

• Master TrayIcon to control all running instances of AutoHotkey http://www.autohotkey.com/forum/viewtopic.php?p=142958#142958
• Extract Informations about TrayIcons http://www.autohotkey.com/forum/viewtopic.php?t=17314

WM_COMMAND = 0x111
ID_FILE_EXIT = 65405
PostMessage, WM_COMMAND, ID_FILE_EXIT, 0, , <window-title>

WM_COMMAND = 0x111
ID_FILE_EXIT = 65405
PostMessage, WM_COMMAND, ID_FILE_EXIT, 0, , DimScreen Screen

WM_COMMAND = 0x111
ID_FILE_EXIT = 65405
DetectHiddenWindows, On

WinGet, AList, List, ahk_class AutoHotkey       ; Make a list of all running AutoHotkey programs
Loop %AList% {                                  ; Loop through the list
  ID := AList%A_Index%
  WinGetTitle, ATitle, ahk_id %ID%              ; (You'll notice this isn't the same 'window title')
  MsgBox, 3, %A_ScriptName%, %ATitle%`n`nEnd?
  IfMsgBox Cancel
    Break
  IfMsgBox Yes
    PostMessage,WM_COMMAND,ID_FILE_EXIT,0,,% "ahk_id" AList%A_Index%   ; End the process (65404 to suspend, 65403 to pause)
}
ExitApp

• Method 1: Wait for status line to say "Done"
  See example in file WebsiteNav.ahk
  
  
• Method 2: call IEReady()
  [Only works for Internet Explorer (afik)]
  See post "Determine if a WebPage is completely loaded in IE" : http://www.autohotkey.com/forum/topic19256.html
  See example in file WebsiteNav.ahk
  1. Download Com.zip from: http://www.autohotkey.net/~Sean/Lib/COM.zip
     (See "COM Standard Library" post: http://www.autohotkey.com/forum/topic22923.html)
     Unzip and place COM.ahk here: C:\Program Files\AutoHotkey\Lib\COM.ahk
     
  2. Download function IEReady from: http://www.autohotkey.com/forum/topic19256.html
     Add fuction IEReady to your .ahk code
  3. Place a call to IEReady() in your .ahk code when you want to wait until the page is loaded.
  
  
• Method 3: See "Detect when a page is loaded (reliable, cross-browser)" post: http://www.autohotkey.com/forum/topic35056.html
  
  
• Methods 4,5,6,...
  For more advanced methods see these two posts:
  ("This is left as an exercise for the student", which is what the professor says when it's over his head.)
  • Automation IE7 Navigation and Scripting with Tabs
    http://www.autohotkey.com/forum/viewtopic.php?t=30599
  • IE and Gui Browser Com Tutorial
    http://www.autohotkey.com/forum/viewtopic.php?t=34972

• Method 1: Blindly hit the {Tab} key a certain number of times to position us where we want to be.
  (Not very reliable. e.g. User may have Google toolbar installed, which we'd have to tab through.
  Or perhaps Yahoo toolbar. Or no toolbar. Who knows...)
  Example:
  

  Send {Tab 34}  ;say, 34 tabs gets us where we want to be.
  

  
  
• Method 2. Hit the {Tab} key until certain text appears in the status bar
  For this example, assume we are at http://www.autohotkey.com/ and we wish to position ourselves on the Wiki link:

  ; For this example, Tab until we find the autoHotkey "Wiki" link
  ; When we tab to the AutoHotkey "Wiki" link, the status bar says "http://www.autohotkey.com/wiki/"
  target := "http://www.autohotkey.com/wiki/"
  loop, 40
  {
    sleep 10  ;this pause may help
    StatusBarGetText, StatBar, , AutoHotkey - Free Mouse and Keyboard Macro Program
    if (StatBar = target)
    {
      goto FOUNDIT
    }
    Send, {Tab}
  }
  ;If we drop out here, it means we failed to find our target after 40 tabs
  MsgBox Failed to find %target%
  ExitApp
  
  FOUNDIT:
  MsgBox Found target %target%
  

  
  
• Method 2.5 Hit Shift+Tab to tab backwards until certain text appears in the status bar
  (May be useful if tabbing forwards doesn't work)
  
  
• Method 3. Search for word which is link you want to click on
  
  
• Method 4. Jump directly to the control
  The JavaScript method—we place some JavaScript code in the address bar and execute it to jump directly to the control. This is a faster and more reliable technique, but it's a bit more complicated to set up. We use AutoHotkey ControlSetText to place the JavaScript code in the address bar, specifying the HTML control ID, or the control NAME, of the control we want to jump to, then we use AutoHotkey ControlSend to execute that JavaScript.
  
  For this example, assume we are at http://www.autohotkey.com/wiki/ and we wish to position ourselves in the Search field.
  Determine the ID or NAME of the control:
  • Method 1: Read and decypher the HTML source code. Look for " ID="
    e.g. for page http://www.autohotkey.com/wiki/
    we find this line of code:

    <INPUT id=searchInput title="Search AutoHotkey [f]" accessKey=f name=search>
              ^^^^^^^^^^^                                                ^^^^^^
    

    Here our ID is searchInput, and our NAME is search (we only need one. Either ID or NAME. The ID is best if it's available.)
    
    
  • Method 2: Use a tool to help us find the ID or NAME
    1. Use the Microsoft "Internet Explorer Developer Toolbar" for Internet Explorer 7.
       (Note: for Internet Explorer 8, see "Discovering Internet Explorer Developer Tools" at http://msdn.microsoft.com/en-us/library/cc848894(VS.85).aspx )
       1. Download and install : http://www.microsoft.com/downloads/details.aspx?familyid=E59C3964-672D-4511-BB3E-2D5E1DB91038&displaylang=en
       2. Navigate to your webpage (using Internet Explorer 7)
       3. Bring up the "IE Developer Toolbar". (Note: If you do not see the "IE Developer Toolbar" button on the toolbar, it may be off to the right. Click the right-facing arrows at the end of the IE7 command bar to view all available toolbar buttons.)
       4. FIND -> SELECT ELEMENT BY CLICK
       5. Move your mouse to the desired element and click.
       6. In the middle pane ('Attribute:') scroll down and find the ID string.
          If there is no ID string, find the NAME string.
          If there is no NAME string, cripes, it gets a bit difficult. You'll
          have to read up on Javascript and the DOM (Document Object Model).
    2. Use Firefox and install the Firebug add-on at http://getfirebug.com/
    3. There are other similar programs to help you examine the source code for web pages. Here are a few:
       • PageSpy — http://www.sembel.net
       • Debugbar — http://www.debugbar.com
  
  
  For these examples assume you're at http://www.autohotkey.com/wiki/
  
  • General format using ID:

    ; Position to a Control Using the Control's Unique ID
    ControlSetText, Edit1, javascript:document.getElementById('<element-ID>')[0].focus()
    ControlSend, Edit1, {Enter}, <window-title>
    Sleep 100     ;give it a moment too do it's thing (important)
    

    (Caution: getElementById is case sensitive! I originally tried getElementByID (last letter D instead of d) and it didn't work.)
    
    Example using ID:

    ; Position to a Control Using the Control's Unique ID
    ; For this example the control's ID is searchInput
    ; and the window title contains the word AutoHotkey
    ControlSetText, Edit1, javascript:document.getElementById('searchInput').focus()
    ControlSend, Edit1, {Enter}, AutoHotkey
    Sleep 100     ;give it a moment too do it's thing (important)
    

  • General format using NAME:

    ; Position to a Control Using the Control's NAME
    ControlSetText, Edit1, javascript:document.getElementsByName('<element-name>')[0].focus()
    ControlSend, Edit1, {Enter}, <window-title>
    Sleep 100     ;give it a moment too do it's thing (important)
    

    Example using NAME:

    ; Position to a Control Using the Control's NAME
    ; For this example the control's NAME is search
    ; and the window title contains the word AutoHotkey
    ControlSetText, Edit1, javascript:document.getElementsByName('search')[0].focus()
    ControlSend, Edit1, {Enter}, AutoHotkey
    Sleep 100     ;give it a moment too do it's thing (important)
    

    If more than one control has the same name:

    1. Go kick George Foreman in the shin for naming all 5 of his sons "George" (and two of his daughters).
    2. Then figure out what number to use instead of [0] to get to the n'th control with that NAME.
       
       (Note: There is no legal way to use the NAME attribute from such tags as DIV or SPAN, according to the W3C HTML 4.01 specs. You must confine the usage of this attribute to such tags as INPUT, IMG, FRAME, IFRAME, FORM, MAP, PARAM, META, OBJECT, A, SELECT, APPLET, TEXTAREA, or BUTTON. (Those who use XML or XHTML or XFILES or whatever may have different rules to play by.)

    
    If the control you want has no ID or NAME:

    • Argh! This is getting hard! You'll have to go read up about JavaScript and the DOM (Document Object Model)
      Some things you could try:

    javascript:document.getElementsByTagName('a')[6].focus() ; Get the 7th <A> tag in the document (numbering begins with 0).
    javascript:document.links[6].focus()                     ; Get the 7th link in the document (numbering begins with 0).
    

    
    
• Methods 5,6,7,...
  For more advanced methods see these two posts:
  • Automation IE7 Navigation and Scripting with Tabs
    http://www.autohotkey.com/forum/viewtopic.php?t=30599
    
  • IE and Gui Browser Com Tutorial
    http://www.autohotkey.com/forum/viewtopic.php?t=34972
    ("This is left as an exercise for the student", which again is what the professor says when it's over his head.)

WinGetPos, winposX, winposY, Width, Height, A  ;Get window Width, Height
;MsgBox, 0, , winposX=%winposX%`n winposY=%winposY% `nWidth=%Width% `nHeight=%Height%,

;Calculate a starting position
X := Width - 60
Y := Height / 2
MouseMove, X, Y, 7

MsgBox, 0, , Move left until we find "not white", 1.2

;move left until we find "not white"
loop 200
{
    MouseMove, X, Y, 0
    PixelGetColor, color, X, Y, RGB
    ;MsgBox, 0, , color=%color%, 0.1
    if (color <> "0xFFFFFF")
    {
      Goto FOUND_TCOLOR
    }
    X -= 1
}
;If we drop out here, it means we failed to find our target
MsgBox, 0, , Failed to find color "not white", 2
goto Exit

FOUND_TCOLOR:
MsgBox, 0, , Found "not white". color = %color%, 2

Exit:
MsgBox, 0, , The End, 2
ExitApp

• Commands dealing with files start with FILE
• Commands dealing with windows start with WIN
• Commands dealing with text start with STRING

• Commands that retrieve data from somewhere contain GET
• Commands that apply data to somewhere contain SET

1. read the Tutorial
2. the Scripts page
3. the FAQ

1. Hotstrings
2. Hotkeys
3. Mouse Clicks & Mouse HotKeys
4. Variables
5. Loops - especially Parsing Loops
6. String commands - (e.g. StringMid, StringReplace)
7. If,Else statements
8. Expressions
9. Arrays & Dynamic variables - (StringSplit)
10. GoSub & Functions
11. GUIs
12. Windows Messages
13. DllCall

;Press ESC to cancel this script
Esc::ExitApp

Run, ShowParams.exe  hello  goodbye  Friday

Run, autohotkey.exe  ShowParams.ahk  hello  goodbye  Friday

Run, cscript.exe  ShowParams.vbs  hello  goodbye  Friday

Run, cscript.exe  ShowParams.js  hello  goodbye  Friday

                    ┌───── cmd.exe strips off these outer " ───────┐
Run, "%comspec%" /c ""ShowParams.ahk"  "hello"  "goodbye"  "friday"", , Hide

command = ShowParams.ahk
params = hello goodbye Friday
res := DllCall("shell32\ShellExecuteA"
      , "UInt", 0             ; hwnd
      , "UInt", 0             ; lpOperation
      , "Str", command        ; lpFile
      , "Str", params         ; lpParameters
      , "Str", A_WorkingDir   ; lpDirectory
      , "UInt", 0)            ; nShowCmd
MsgBox (%ErrorLevel%) %res%

How does a C/C++ program on Windows get argv[]? The C/C++ compiler which compiles the program secretly adds extra code to the executable that retrieves and parses the command line to extract the parameters before calling WinMain (or main). Thus, for a C/C++ executable on Windows, the parameter parsing rules are determined by the C/C++ compiler that compiled the program.

AutoHotkey is written in C++ and obtains its parameters via the argv[] vector.¹ Thus it uses the Microsoft C/C++ Parameter Parsing Rules. The rules are: