Trim leading spaces including tabs

Question

I need to read files using vbscript and remove all leading spaces including any tabs. I now LTRIM will remove the leading spaces but how do I remove tabs also.

Thanks.

Answer 1

This function removes all leading whitespace (spaces, tabs etc) from a string:

Function LTrimEx(str)
  Dim re
  Set re = New RegExp
  re.Pattern = "^\s*"
  re.Multiline = False
  LTrimEx = re.Replace(str, "")
End Function

Answer 2

Andrew's answer is not correct. LTrim, RTrim and Trim only removes spaces, not tabs.

I reformatted your code, and added a function to strip any leading or trailing characters.

filename="test.txt"

set fso = createobject("scripting.filesystemobject")
set f = fso.opentextfile(filename)

do while not f.AtEndOfStream
  s = TrimChars(f.readline, " " + vbTab)
  wscript.echo "|" & s & "|"
loop

f.close

set f = nothing
set fso = nothing

''---

function TrimChars(s, sChars)
  dim n, nLen, nStart

  nLen = Len(s)
  if nLen = 0 then
    TrimChars = s
    exit function
  end if

  ''- skip leading chars
  n = 1
  do while (n <= nLen) And (InStr(sChars, Mid(s, n, 1)) > 0)
    n = n + 1
  loop
  nStart = n

  ''- skip trailing chars
  n = nLen
  do while (n > nStart) And (InStr(sChars, Mid(s, n, 1)) > 0)
    n = n - 1
  loop

  ''- return remaining chars
  nLen = n - nStart + 1
  if (nLen > 0) and (nStart <= len(s)) then
    TrimChars = Mid(s, nStart, nLen)
  else
    TrimChars = ""
  end if
end function

Answer 3

Function LTrimEx(str)
    Do Until x
     If Left(str, 1) = Chr(32) Or Left(str, 1) = Chr(9) then
      str = Right(str, Len(str) - 1)
     Else
      x = true
     End If
    Loop
    LTrimEx = str
End Function

Answer 4

For a both left and right trim (including tabs, carriage return, line feeds, spaces) in a multiline string this will work.

Function MultilineTrim (Byval TextData)
    Dim textRegExp
    Set textRegExp = new regexp
    textRegExp.Pattern = "\s{0,}(\S{1}[\s,\S]*\S{1})\s{0,}"
    textRegExp.Global = False
    textRegExp.IgnoreCase = True
    textRegExp.Multiline = True

    If textRegExp.Test (TextData) Then
     MultilineTrim = textRegExp.Replace (TextData, "$1")
    Else
     MultilineTrim = ""
    End If
End Function