StrTok

From NSIS Wiki

Author: deguix (talk, contrib)


Description

Requires: LogicLib header file.

Version: 2.0.1.

This function returns a specific part of a string between separators.

How To Use

Syntax

${StrTok} "ResultVar" "String" "Separators" "ResultPart" "SkipEmptyParts"

or

Push "String"
Push "Separators"
Push "ResultPart"
Push "SkipEmptyParts"
Call StrTok
Pop "ResultVar"

Parameters

ResultVar
Variable where the part indicated by ResultPart found in String is returned. If no Separators are found, the entire string is considered the one and only part existent.
String
String where to search for SubString.
Separators
Characters to find in String.
ResultPart
Number which indicates which part inside two Separators (including the start and end of String). This number starts at zero (0). "L" is the last part that can be found. Default is "L" (last part).
SkipEmptyParts
Indicates whether to skip empty string parts. 1 = True, 0 = False. Default is 1 (True).

Example

${StrTok} $0 "This is, or is not, just an example" " ," "4" "1"
;$0 = "not"

Function Code

!define StrTok "!insertmacro StrTok"
 
!macro StrTok ResultVar String Separators ResultPart SkipEmptyParts
  Push "${String}"
  Push "${Separators}"
  Push "${ResultPart}"
  Push "${SkipEmptyParts}"
  Call StrTok
  Pop "${ResultVar}"
!macroend
 
Function StrTok
/*After this point:
  ------------------------------------------
  $0 = SkipEmptyParts (input)
  $1 = ResultPart (input)
  $2 = Separators (input)
  $3 = String (input)
  $4 = SeparatorsLen (temp)
  $5 = StrLen (temp)
  $6 = StartCharPos (temp)
  $7 = TempStr (temp)
  $8 = CurrentLoop
  $9 = CurrentSepChar
  $R0 = CurrentSepCharNum
  */
 
  ;Get input from user
  Exch $0
  Exch
  Exch $1
  Exch
  Exch 2
  Exch $2
  Exch 2
  Exch 3
  Exch $3
  Exch 3
  Push $4
  Push $5
  Push $6
  Push $7
  Push $8
  Push $9
  Push $R0
 
  ;Parameter defaults
  ${IfThen} $2 == `` ${|} StrCpy $2 `|` ${|}
  ${IfThen} $1 == `` ${|} StrCpy $1 `L` ${|}
  ${IfThen} $0 == `` ${|} StrCpy $0 `0` ${|}
 
  ;Get "String" and "Separators" length
  StrLen $4 $2
  StrLen $5 $3
  ;Start "StartCharPos" and "ResultPart" counters
  StrCpy $6 0
  StrCpy $8 -1
 
  ;Loop until "ResultPart" is met, "Separators" is found or
  ;"String" reaches its end
  ResultPartLoop: ;"CurrentLoop" Loop
 
  ;Increase "CurrentLoop" counter
  IntOp $8 $8 + 1
 
  StrSearchLoop:
  ${Do} ;"String" Loop
    ;Remove everything before and after the searched part ("TempStr")
    StrCpy $7 $3 1 $6
 
    ;Verify if it's the "String" end
    ${If} $6 >= $5
      ;If "CurrentLoop" is what the user wants, remove the part
      ;after "TempStr" and itself and get out of here
      ${If} $8 == $1
      ${OrIf} $1 == `L`
        StrCpy $3 $3 $6
      ${Else} ;If not, empty "String" and get out of here
        StrCpy $3 ``
      ${EndIf}
      StrCpy $R0 `End`
      ${ExitDo}
    ${EndIf}
 
    ;Start "CurrentSepCharNum" counter (for "Separators" Loop)
    StrCpy $R0 0
 
    ${Do} ;"Separators" Loop
      ;Use one "Separators" character at a time
      ${If} $R0 <> 0
        StrCpy $9 $2 1 $R0
      ${Else}
        StrCpy $9 $2 1
      ${EndIf}
 
      ;Go to the next "String" char if it's "Separators" end
      ${IfThen} $R0 >= $4 ${|} ${ExitDo} ${|}
 
      ;Or, if "TempStr" equals "CurrentSepChar", then...
      ${If} $7 == $9
        StrCpy $7 $3 $6
 
        ;If "String" is empty because this result part doesn't
        ;contain data, verify if "SkipEmptyParts" is activated,
        ;so we don't return the output to user yet
 
        ${If} $7 == ``
        ${AndIf} $0 = 1 ;${TRUE}
          IntOp $6 $6 + 1
          StrCpy $3 $3 `` $6
          StrCpy $6 0
          Goto StrSearchLoop
        ${ElseIf} $8 == $1
          StrCpy $3 $3 $6
          StrCpy $R0 "End"
          ${ExitDo}
        ${EndIf} ;If not, go to the next result part
        IntOp $6 $6 + 1
        StrCpy $3 $3 `` $6
        StrCpy $6 0
        Goto ResultPartLoop
      ${EndIf}
 
      ;Increase "CurrentSepCharNum" counter
      IntOp $R0 $R0 + 1
    ${Loop}
    ${IfThen} $R0 == "End" ${|} ${ExitDo} ${|}
 
    ;Increase "StartCharPos" counter
    IntOp $6 $6 + 1
  ${Loop}
 
/*After this point:
  ------------------------------------------
  $3 = ResultVar (output)*/
 
  ;Return output to user
 
  Pop $R0
  Pop $9
  Pop $8
  Pop $7
  Pop $6
  Pop $5
  Pop $4
  Pop $0
  Pop $1
  Pop $2
  Exch $3
FunctionEnd

Versions History

2.0.1
Fixed stack problems.

Credits

Author: Diego Pedroso (deguix).
Based on StrTok function.

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