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Check if a string is Char(zero)

8 posts

DiLDoG#

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