Check for spaces in a directory path

Author: Afrow UK (talk, contrib)

Description

This script will check a string (or directory path) for spaces and returns the number of spaces found in the string.

Updated 12th January 2005

Usage

The CheckForSpaces function should be called in the Leave function of the Directory page. Below are the two ways to implement this (through Classic UI and Modern UI). Both implement a function called "DirectoryLeave" as the Directory pages' Leave function.

MUI

Use this if you are using Modern UI (!include MUI.nsh).

!define MUI_PAGE_CUSTOMFUNCTION_LEAVE "DirectoryLeave"
!insertmacro MUI_PAGE_DIRECTORY

Non-MUI

Use this if you aren't using Modern UI.

Page Directory "" "" "DirectoryLeave"

DirectoryLeave Function

This gives an example of what your "DirectoryLeave" function should look like.

Function DirectoryLeave
 
  # Call the CheckForSpaces function.
  Push $INSTDIR # Input string (install path).
   Call CheckForSpaces
  Pop $R0 # The function returns the number of spaces found in the input string.
 
  # Check if any spaces exist in $INSTDIR.
  StrCmp $R0 0 NoSpaces
 
    # Plural if more than 1 space in $INSTDIR.
    StrCmp $R0 1 0 +3
      StrCpy $R1 ""
    Goto +2
      StrCpy $R1 "s"
 
    # Show message box then take the user back to the Directory page.
    MessageBox MB_OK|MB_ICONEXCLAMATION "Error: The Installaton directory \
    has $R0 space$R1.$\nPlease remove the space$R1."
    Abort
 
  NoSpaces:
 
FunctionEnd

The Function

Function CheckForSpaces
 Exch $R0
 Push $R1
 Push $R2
 Push $R3
 StrCpy $R1 -1
 StrCpy $R3 $R0
 StrCpy $R0 0
 loop:
   StrCpy $R2 $R3 1 $R1
   IntOp $R1 $R1 - 1
   StrCmp $R2 "" done
   StrCmp $R2 " " 0 loop
   IntOp $R0 $R0 + 1
 Goto loop
 done:
 Pop $R3
 Pop $R2
 Pop $R1
 Exch $R0
FunctionEnd

-Stu