5 replies to this topic

[blindwig]

I ran into some quirks while trying to control environmental variable expansion using the ExpandEnvStrings option, so I wrote a function to parse a string and return an expanded version of that string:

CODE

Func _ExpandEnvStrings($sInput)
Dim $aPart = StringSplit($sInput,'%')
If @error Then
SetError(1)
Return $sInput
EndIf
Dim $sOut = $aPart[1], $i = 2, $env = ''
;loop through the parts
While $i <= $aPart[0]
$env = EnvGet($aPart[$i])
If $env <> '' Then ;this part is an expandable environment variable
$sOut = $sOut & $env
$i = $i + 1
If $i <= $aPart[0] Then $sOut = $sOut & $aPart[$i]
ElseIf $aPart[$i] = '' Then ;a double-percent is used to force a single percent
$sOut = $sOut & '%'
$i = $i + 1
If $i <= $aPart[0] Then $sOut = $sOut & $aPart[$i]
Else ;this part is to be returned literally
$sOut = $sOut & '%' & $aPart[$i]
EndIf
$i = $i + 1
WEnd
Return $sOut
EndFunc

Example:

CODE

MsgBox(0, '', _ExpandEnvStrings('the file "%comspec%" is your command interpreter'), 5)

[FuryCell]

Awesome function!
Just tried on this string.

"Path=%PATH% %%"

It even knew to take the two %'s literally.
Better than Opt("ExpandEnvStrings",1) becuase as you said it's not quirky and it does not affect all strings , only the ones you want.
Good Job!

P.S. I might make an _ExpandVariables func like this if you woundn't mind me using your idea.

Edited by SolidSnake, 12 June 2005 - 01:01 PM.

[blindwig]

Awesome function!   
Just tried on this string.

"Path=%PATH% %%"

It even knew to take the two %'s literally.
Better than Opt("ExpandEnvStrings",1) becuase as you said it's not quirky and it does not affect all strings , only the ones you want.
Good Job!

P.S. I might make an _ExpandVariables func like this if you woundn't mind me using your idea.

<{POST_SNAPBACK}>

Yup, I tested it and tried to make it as close to "normal" (ie, as the command intrepreter would handle it) as I could. It successfully handles these tricky ones:
'%%path%%'
'%path%path%'

If you want to make a generic version (one that can use any character to "wrap" a variable), Change the header:
Func _ExpandEnvStrings($sInput, $Delim='%')
And then replace any '%' in the function with $Delim.
Replace the EnvGet with your own function, or I'd recommend using my table UDF to store your own variables.

[blindwig]

OK, I just added another feature to this routine. Now, in addition to looking for variables like %SystemDir%, it also looks for passes parameters, such as %1 %2 %3 etc. It takes an optional array of parameters (this array is assumed to be 1-base, like the $CmdLine built-in) and replaces %1 with element 1 of the array, %2 with the element 2, etc.
I am now working on wrapping it to find default commands for a particular filetype (so that I don't have to do a ShellExecute, I can actually look at the shell command and execute it myself)

Here's the code:

CODE

;Expands environment variables in a string, such as %COMSPEC% etc
;Also looks for %1 %2 %3 etc and substitutes from $aParameter, which is a 1-based 1-dimensional array
Func _ExpandEnvStrings($sInput, $aParameter=0)
Dim $aPart = StringSplit($sInput,'%')
If @error Then
SetError(1)
Return $sInput
EndIf
Dim $sOut = $aPart[1], $i = 2, $env = ''
;loop through the parts
While $i <= $aPart[0]
$env = EnvGet($aPart[$i])
If $env <> '' Then ;this part is an expandable environment variable
$sOut = $sOut & $env
$i = $i + 1
If $i <= $aPart[0] Then $sOut = $sOut & $aPart[$i]
ElseIf $aPart[$i] = '' Then ;a double-percent is used to force a single percent
$sOut = $sOut & '%'
$i = $i + 1
If $i <= $aPart[0] Then $sOut = $sOut & $aPart[$i]
Else ;this part may be literal, or may request a parameter
;first check for a parameter request
if Not UBound($aParameter,0) = 1 Then
If IsString($aParameter) Then
$aParameter = _ArrayCreate(1, $aParameter)
Else
Local $aParameter[1]
EndIf
EndIf
Local $j = 1, $num
While $j <= StringLen($aPart[$i]) And StringIsDigit(stringmid($aPart[$i], $j, 1))
$j = $j + 1
WEnd
$Num = StringLeft($aPart[$i], $j - 1)
If StringIsInt($num) Then ;parameter requested
If Int($num)<=$aParameter[0] Then ;allowed
$sOut = $sOut & $aParameter[int($num)] & StringTrimLeft($aPart[$i], $j - 1)
Else ;denied
$sOut = $sOut & StringTrimLeft($aPart[$i], $j - 1)
EndIf
Else ;return literal
$sOut = $sOut & '%' & $aPart[$i]
EndIf
EndIf
$i = $i + 1
WEnd
Return $sOut
EndFunc

[MAli]

Here is another example using RegEx:

AutoIt        expandcollapse  popup

Func _ExpandEnvStrings($sExpr)
    Local Const $sPattern = "\%[\d\w()_]+\%"
    Local $a
    Local $sEnv
    Local $p1, $p2
    Local $sMatch
    Local $sMatchStripPct
    Local $sResult

    $a = StringRegExp ($sExpr, $sPattern, 3)
    $sResult = $sExpr

    If IsArray($a) Then
        For $sMatch In $a
            $p1 = StringInStr($sMatch, "%", 0, 1)
            $p2 = StringInStr($sMatch, "%", 0, 2)
            $sMatchStripPct = StringMid($sMatch, $p1+1, $p2-$p1-1)
            $sEnv = EnvGet($sMatchStripPct)
            If $sEnv = "" Then $sEnv = $sMatch
            $sResult = StringReplace($sResult, $sMatch, $sEnv, 1)
        Next
    EndIf

    Return $sResult
EndFunc

Edited by MAli, 19 March 2013 - 09:49 AM.

[Melba23]

MAli,

Oh come on! The post above yours dates from nearly 8 years ago. Please pay attention when you post - we do not approve of resurrecting threds this old as the language has changed so much since then.

M23

P.S. Welcome to the AutoIt forum anyway - just be more careful in future.

Edited by Melba23, 19 March 2013 - 01:06 PM.
Fixed BB tags