DiLDoG
10th September 2004 16:50 UTC

Check if a string is Char(zero)
I'm trying to get the label of a CD using this:

; Get current drive label
DriveInfo::GetDriveLabel "D:\"
Pop $1

But if there is no cd in drive, it returns a zero character (at least I think it is). How do I replace that zero char with "<empty>" for example?

zimsms
10th September 2004 17:01 UTC

strcmp "$1" "0" 0 +2
strcpy $1 "<empty>"

DiLDoG
10th September 2004 17:04 UTC

not the character "0" but Chr(0), so ascii value 0

zimsms
10th September 2004 18:20 UTC

ahh, use "" intead of "0" in the compare then.

DiLDoG
10th September 2004 19:05 UTC

hm doenst seem to work, perhaps it aint Chr(0), but

The plugin uses
GetVolumeInformation(buf,buf2,sizeof(buf2)-1,0,0,0,0,0);

and MSDN sais "If not all the requested information is retrieved, the return value is zero."

And if I display the var in a msgbox or any other thing it displays the square box char.

this is my code as it is now:

    StrCpy $2 ""

again:
    ; Enumerate CD Drives
    EnumCDs::next /NOUNLOAD
    Pop $0
    StrCmp $0 "error" done
    StrCmp $0 "done" done

    ; Get current drive label
    DriveInfo::GetDriveLabel "$0"
    Pop $1
    
    strcmp "$1" "" 0 +2
    strcpy $1 "<empty>"
    
    StrCpy $2 "$2|$0 $1"
    goto again
    
done:
    EnumCDs::next
    Pop $0

    WriteINIStr "$PLUGINSDIR\insertcd.ini" "Field 1" "ListItems" $2

zimsms
10th September 2004 19:22 UTC

What about calling kernel32 directly and bypassing the driveinfo plugin? ie something like this.

DiLDoG
10th September 2004 19:39 UTC

hm cant get that one working at all...

; $0 - Drive to check returns the Disc Serial Number

Function GetDiskVolumeSerialNumber

  !define GetVolumeInformation "Kernel32::GetVolumeInformation(t,*t,i,*i,*i,*i,t,i) i"
  
  StrCpy $R0 "hi"
  System::Call '${GetVolumeInformation}("C:\",,${NSIS_MAX_STRLEN},.r0,,,,${NSIS_MAX_STRLEN})'
  MessageBox MB_OK|MB_ICONSTOP "hi $R0 hi"
  
FunctionEnd  ;GetDiskVolumeSerialNumber

always results in "hi hi hi" Shouldn't R1 be changed there?

Joel
10th September 2004 20:26 UTC

With this works with me:

System::Call 'kernel32::GetVolumeInformation(t "C:\", t .r0 , i 255, *i .r1, *i .r2, *i .r3, *i .r4, i 255) i .r11'
DetailPrint $0
DetailPrint $1
DetailPrint $2
DetailPrint $3
DetailPrint $4
DetailPrint $R1