StrContains.nsh

; StrContains Written by kenglish_hi http://nsis.sourceforge.net/StrContains
; Adapted from StrReplace written by dandaman32
; Modified to check for * Wildcard in variable ISOFileName for YUMI and UUI by Lance http://www.pendrivelinux.com
; This function does a case sensitive searches for an occurrence of a substring in a string. 
; It returns the substring if it is found. 
; Otherwise it returns null(""). 
Var /Global STR_HAYSTACK
Var /Global STR_NEEDLE
Var /Global STR_CONTAINS_VAR_1
Var /Global STR_CONTAINS_VAR_2
Var /Global STR_CONTAINS_VAR_3
Var /Global STR_CONTAINS_VAR_4
Var /Global STR_RETURN_VAR
Var /Global WILD
 
Function StrContains
  Exch $STR_NEEDLE
  Exch 1
  Exch $STR_HAYSTACK
  ; Uncomment to debug
  ;MessageBox MB_OK 'STR_NEEDLE = $STR_NEEDLE STR_HAYSTACK = $STR_HAYSTACK '
    StrCpy $STR_RETURN_VAR ""
    StrCpy $STR_CONTAINS_VAR_1 -1
    StrLen $STR_CONTAINS_VAR_2 $STR_NEEDLE
    StrLen $STR_CONTAINS_VAR_4 $STR_HAYSTACK
    loop:
      IntOp $STR_CONTAINS_VAR_1 $STR_CONTAINS_VAR_1 + 1
      StrCpy $STR_CONTAINS_VAR_3 $STR_HAYSTACK $STR_CONTAINS_VAR_2 $STR_CONTAINS_VAR_1
      StrCmp $STR_CONTAINS_VAR_3 $STR_NEEDLE found
      StrCmp $STR_CONTAINS_VAR_1 $STR_CONTAINS_VAR_4 done
      Goto loop
    found:
      StrCpy $STR_RETURN_VAR $STR_NEEDLE
      Goto done
    done:
   Pop $STR_NEEDLE ;Prevent "invalid opcode" errors and keep the
   Exch $STR_RETURN_VAR 
FunctionEnd

!macro _StrContainsConstructor OUT NEEDLE HAYSTACK
  Push "${HAYSTACK}"
  Push "${NEEDLE}"
  Call StrContains
  Pop "${OUT}"
!macroend
 
!define StrContains '!insertmacro "_StrContainsConstructor"'