NSIS Wiki - User contributions [en]

DVD functions

2008-07-26T15:45:11Z

Message: /* The Functions */

{{PageAuthor|Message}}

== Description ==
Because the [[CDRom plug-in]] is unable to read any data from DVDs, these functions are meant as a replacement with two primary functions: Finding CD/DVD-ROM drives in the user's system and reading CD/DVD-ROM disc labels.
== How To Use ==
<highlight-nsis>/* --------------------------------

DVD functions - a replacement for the CD-ROM plugin for NSIS
Created by Message, 2007

Usage example:
push "" ;push input to stack
call DVD_GetNextDrive ;call function
pop $0 ;pop output from stack

push $0 ;push input to stack
call DVD_GetLabel ;call function
pop $1 ;pop output from stack

call DVD_Unload ;unload from memory

DVD_GetNextDrive : Finds the first/next CD/DVD-ROM drive and returns its full path on the stack.

input : The function will search for the first CD/DVD drive AFTER this specified
drive letter. So with input "C:\" the function will start searching at D:\.
Only the first character of the input is used, so it should be a Capital
letter from A to Z.
If the input does not start with A-Z, the function returns an empty string
("") on the stack.
If the input is empty, the function starts scanning at A:\.
If the function reaches Z:\, it will continue searching at A:\.
output : The full path of the first CD/DVD-ROM drive the function found, for example
"E:\".
If the function could not find any CD/DVD-ROM drive after (and before) the
specified input drive, it will return an empty string ("") on the stack.
If Windows could not find any drives at all (either CD-ROM or otherwise),
the function returns "ERROR". This should never happen.

DVD_GetLabel : Returns the label of the CD/DVD currently in the specified drive on the stack.

input : The full path to the root of the CD/DVD-ROM drive, so for example "E:\".
output : The full volume label of the disc in the drive. If there is no disc in the
drive, or there is some other error, the function will return
"DVDGetLabel_error" on the stack.

DVD_CheckDrive : Checks if the specified drive is a CD/DVD-ROM drive.

input : The full path to the root of the CD/DVD-ROM drive, so for example "E:\".
output : If the drive is a CD/DVD-ROM drive, the function will return "CDROM" on the
stack. (For other possible outputs, see the function code.)

DVD_Unload : Unloads dlls used in other DVD functions. Call this function from .onGUIEnd
to prevent .dll files from remaining in the user's temp folder. No input or
output.
*/
</highlight-nsis>
== The Functions ==
<highlight-nsis>
Function DVD_GetNextDrive
Exch $R1
Push $R0
Push $R2
Push $R3
Push $R4

;get all drives (return to $R0, bitwise)
System::Call /NOUNLOAD 'kernel32::GetLogicalDrives() i .r10'
StrCmp $R0 "0" 0 +3 ;if no drives found, error
StrCpy $R1 "ERROR"
goto break

;If no parameter was supplied at all, assume we're starting at A:\ and set the "no parameters" flag.
StrCmp $R1 "" 0 +4
StrCpy $R1 "0"
StrCpy $R4 "-1" ;no parameters flag. If $R4 is -1, it will never equal the current drive letter, thus the alphabet cycle check will never kick in
goto loop

;get ascii-number of first char in function parameter
System::Call /NOUNLOAD "*(&t1 r11)i.r12"
System::Call /NOUNLOAD "*$R2(&i1 .r11)"
System::Free /NOUNLOAD $R2
IntOp $R1 $R1 - 65

;check if parameter driveletter is between A and Z
IntCmp $R1 0 0 +2
IntCmp $R1 25 +3 +3
StrCpy $R1 ""
goto break

;backup the (asciiconverted) starting driveletter, for detecting when we've cycled the entire alphabet.
StrCpy $R4 $R1

;If a valid parameter was supplied (ie we had a parameter and we survived so far), start at the driveletter directly after the supplied starting driveletter
IntOp $R1 $R1 + 1
StrCmp $R1 26 0 +2 ;if >Z
StrCpy $R1 0 ; return to A

loop:
IntOp $R2 0x01 << $R1
IntOp $R3 $R2 & $R0
;if (0x01<<driveletter & drivesfound) == 0x01<<driveletter (in other words, if there is a drive mounted at this driveletter)
StrCmp $R3 $R2 0 NoDriveHere
;convert asciinumber of driveletter to character
IntOp $R2 $R1 + 65
IntFmt $R2 %c $R2
;get type of drive
System::Call /NOUNLOAD 'kernel32::GetDriveType(t "$R2:\") i .r13'
StrCmp $R3 5 0 NoDriveHere
;type is CDROM
StrCmp $R1 $R4 0 +3 ;if we've cycled the entire alphabet (we ended up at the drive specified in the starting paramater)
StrCpy $R1 "" ; no more CDROM drives found
goto break
StrCpy $R1 "$R2:\" ;else: next CDROM drive found
goto break
NoDriveHere:
StrCmp $R1 $R4 0 +3 ;if we've cycled the entire alphabet
StrCpy $R1 "" ; no CDROM drive found
goto break
IntOp $R1 $R1 + 1 ;increment driveletter
StrCmp $R1 26 0 loop ;if >Z
StrCmp $R4 "-1" 0 +3 ; if there were no parameters
StrCpy $R1 "" ; no CDROM drive found
goto break
StrCpy $R1 0 ; else return to A
goto loop
break:

Pop $R4
Pop $R3
Pop $R2
Pop $R0
Exch $R1
FunctionEnd

Function DVD_GetLabel
Exch $R0
Push $R1
Push $R2

;leave function if no parameter was supplied
StrCmp $R0 "" break

;get the label of the drive (return to $R1)
System::Call /NOUNLOAD 'Kernel32::GetVolumeInformation(t r10,t.r11,i ${NSIS_MAX_STRLEN},*i,*i,*i,t.r12,i ${NSIS_MAX_STRLEN})i.r10'
StrCmp $R0 0 0 +3
StrCpy $R0 "DVDGetLabel_error"
goto +2
StrCpy $R0 $R1
break:

Pop $R2
Pop $R1
Exch $R0
FunctionEnd

Function DVD_CheckDrive
Exch $R0
Push $R1
System::Call /NOUNLOAD 'kernel32::GetDriveType(t "$R0") i .r11'
StrCmp $R1 0 0 +2
StrCpy $R0 "UNKNOWN"
StrCmp $R1 1 0 +2
StrCpy $R0 "INVALID"
StrCmp $R1 2 0 +2
StrCpy $R0 "REMOVABLE"
StrCmp $R1 3 0 +2
StrCpy $R0 "FIXED"
StrCmp $R1 4 0 +2
StrCpy $R0 "REMOTE"
StrCmp $R1 5 0 +2
StrCpy $R0 "CDROM"
StrCmp $R1 6 0 +2
StrCpy $R0 "RAMDISK"
Pop $R1
Exch $R0
FunctionEnd

Function DVD_Unload
Push $R0
System::Call 'kernel32::GetLogicalDrives() i .r10 ? u'
Pop $R0
FunctionEnd
</highlight-nsis>

[[Category:System Related Functions]]

DVD functions

2008-07-26T00:40:13Z

Message:

{{PageAuthor|Message}}

== Description ==
Because the [[CDRom plug-in]] is unable to read any data from DVDs, these functions are meant as a replacement with two primary functions: Finding CD/DVD-ROM drives in the user's system and reading CD/DVD-ROM disc labels.
== How To Use ==
<highlight-nsis>/* --------------------------------

DVD functions - a replacement for the CD-ROM plugin for NSIS
Created by Message, 2007

Usage example:
push "" ;push input to stack
call DVD_GetNextDrive ;call function
pop $0 ;pop output from stack

push $0 ;push input to stack
call DVD_GetLabel ;call function
pop $1 ;pop output from stack

call DVD_Unload ;unload from memory

DVD_GetNextDrive : Finds the first/next CD/DVD-ROM drive and returns its full path on the stack.

input : The function will search for the first CD/DVD drive AFTER this specified
drive letter. So with input "C:\" the function will start searching at D:\.
Only the first character of the input is used, so it should be a Capital
letter from A to Z.
If the input does not start with A-Z, the function returns an empty string
("") on the stack.
If the input is empty, the function starts scanning at A:\.
If the function reaches Z:\, it will continue searching at A:\.
output : The full path of the first CD/DVD-ROM drive the function found, for example
"E:\".
If the function could not find any CD/DVD-ROM drive after (and before) the
specified input drive, it will return an empty string ("") on the stack.
If Windows could not find any drives at all (either CD-ROM or otherwise),
the function returns "ERROR". This should never happen.

DVD_GetLabel : Returns the label of the CD/DVD currently in the specified drive on the stack.

input : The full path to the root of the CD/DVD-ROM drive, so for example "E:\".
output : The full volume label of the disc in the drive. If there is no disc in the
drive, or there is some other error, the function will return
"DVDGetLabel_error" on the stack.

DVD_CheckDrive : Checks if the specified drive is a CD/DVD-ROM drive.

input : The full path to the root of the CD/DVD-ROM drive, so for example "E:\".
output : If the drive is a CD/DVD-ROM drive, the function will return "CDROM" on the
stack. (For other possible outputs, see the function code.)

DVD_Unload : Unloads dlls used in other DVD functions. Call this function from .onGUIEnd
to prevent .dll files from remaining in the user's temp folder. No input or
output.
*/
</highlight-nsis>
== The Functions ==
<highlight-nsis>
Function DVD_GetNextDrive
Exch $R1
Push $R0
Push $R2
Push $R3
Push $R4

;get all drives (return to $R0, bitwise)
System::Call /NOUNLOAD 'kernel32::GetLogicalDrives() i .r10'
StrCmp $R0 "0" 0 +3 ;if no drives found, error
StrCpy $R1 "ERROR"
goto break

;If no parameter was supplied at all, assume we're starting at A:\.
StrCmp $R1 "" 0 +4
StrCpy $R1 "0"
StrCpy $R4 "0"
goto loop

;get ascii-number of first char in function parameter
System::Call /NOUNLOAD "*(&t1 r11)i.r12"
System::Call /NOUNLOAD "*$R2(&i1 .r11)"
System::Free /NOUNLOAD $R2
IntOp $R1 $R1 - 65

;check if parameter driveletter is between A and Z
IntCmp $R1 0 0 +2
IntCmp $R1 25 +3 +3
StrCpy $R1 ""
goto break

;backup the (asciiconverted) starting driveletter, for detecting when we've cycled the entire alphabet.
StrCpy $R4 $R1

;If a valid parameter was supplied (ie we had a parameter and we survived so far), start at the driveletter directly after the supplied starting driveletter
IntOp $R1 $R1 + 1
StrCmp $R1 26 0 +2 ;if >Z
StrCpy $R1 0 ; return to A

loop:
IntOp $R2 0x01 << $R1
IntOp $R3 $R2 & $R0
;if (0x01<<driveletter & drivesfound) == 0x01<<driveletter (in other words, if there is a drive mounted at this driveletter)
StrCmp $R3 $R2 0 NoDriveHere
;convert asciinumber of driveletter to character
IntOp $R2 $R1 + 65
IntFmt $R2 %c $R2
;get type of drive
System::Call /NOUNLOAD 'kernel32::GetDriveType(t "$R2:\") i .r13'
StrCmp $R3 5 0 NoDriveHere
;type is CDROM
StrCmp $R1 $R4 0 +3 ;if we've cycled the entire alphabet (we ended up at the drive specified in the starting paramater)
StrCpy $R1 "" ; no more CDROM drives found
goto break
StrCpy $R1 "$R2:\" ;else: next CDROM drive found
goto break
NoDriveHere:
StrCmp $R1 $R4 0 +3 ;if we've cycled the entire alphabet
StrCpy $R1 "" ; no CDROM drive found
goto break
IntOp $R1 $R1 + 1 ;increment driveletter
StrCmp $R1 26 0 +2 ;if >Z
StrCpy $R1 0 ; return to A
goto loop
break:

Pop $R4
Pop $R3
Pop $R2
Pop $R0
Exch $R1
FunctionEnd

Function DVD_GetLabel
Exch $R0
Push $R1
Push $R2

;leave function if no parameter was supplied
StrCmp $R0 "" break

;get the label of the drive (return to $R1)
System::Call /NOUNLOAD 'Kernel32::GetVolumeInformation(t r10,t.r11,i ${NSIS_MAX_STRLEN},*i,*i,*i,t.r12,i ${NSIS_MAX_STRLEN})i.r10'
StrCmp $R0 0 0 +3
StrCpy $R0 "DVDGetLabel_error"
goto +2
StrCpy $R0 $R1
break:

Pop $R2
Pop $R1
Exch $R0
FunctionEnd

Function DVD_CheckDrive
Exch $R0
Push $R1
System::Call /NOUNLOAD 'kernel32::GetDriveType(t "$R0") i .r11'
StrCmp $R1 0 0 +2
StrCpy $R0 "UNKNOWN"
StrCmp $R1 1 0 +2
StrCpy $R0 "INVALID"
StrCmp $R1 2 0 +2
StrCpy $R0 "REMOVABLE"
StrCmp $R1 3 0 +2
StrCpy $R0 "FIXED"
StrCmp $R1 4 0 +2
StrCpy $R0 "REMOTE"
StrCmp $R1 5 0 +2
StrCpy $R0 "CDROM"
StrCmp $R1 6 0 +2
StrCpy $R0 "RAMDISK"
Pop $R1
Exch $R0
FunctionEnd

Function DVD_Unload
Push $R0
System::Call 'kernel32::GetLogicalDrives() i .r10 ? u'
Pop $R0
FunctionEnd
</highlight-nsis>

[[Category:System Related Functions]]

CDRom plug-in

2008-07-26T00:40:03Z

Message:

{{PageAuthor|Instructor}}

== Description ==

The CD-Rom plugin provides basic functions for finding and interacting with CD-ROM drives. Note: This plugin is not able to read data from DVDs (see [[DVD functions]]).

'''Features:'''
*Open/Close CD-ROM door
*Get CD-ROM status (ready, not ready)
*Get CD-ROM information (volume name, volume serial number)
*Find all CD-ROMs in the system (based on [[Enumerate_CD-ROM_Drives]] plugin)

== Links ==

Download v1.0:<br>
<attach>Cdrom.zip</attach>

[[Category:Plugins]]

DVD functions

2008-07-26T00:35:16Z

Message:

{{PageAuthor|Message}}

== Description ==
Because the [[CD-Rom plugin]] is unable to read any data from DVDs, these functions are meant as a replacement with two primary functions: Finding CD/DVD-ROM drives in the user's system and reading CD/DVD-ROM disc labels.
== How To Use ==
<highlight-nsis>/* --------------------------------

DVD functions - a replacement for the CD-ROM plugin for NSIS
Created by Message, 2007

Usage example:
push "" ;push input to stack
call DVD_GetNextDrive ;call function
pop $0 ;pop output from stack

push $0 ;push input to stack
call DVD_GetLabel ;call function
pop $1 ;pop output from stack

call DVD_Unload ;unload from memory

DVD_GetNextDrive : Finds the first/next CD/DVD-ROM drive and returns its full path on the stack.

input : The function will search for the first CD/DVD drive AFTER this specified
drive letter. So with input "C:\" the function will start searching at D:\.
Only the first character of the input is used, so it should be a Capital
letter from A to Z.
If the input does not start with A-Z, the function returns an empty string
("") on the stack.
If the input is empty, the function starts scanning at A:\.
If the function reaches Z:\, it will continue searching at A:\.
output : The full path of the first CD/DVD-ROM drive the function found, for example
"E:\".
If the function could not find any CD/DVD-ROM drive after (and before) the
specified input drive, it will return an empty string ("") on the stack.
If Windows could not find any drives at all (either CD-ROM or otherwise),
the function returns "ERROR". This should never happen.

DVD_GetLabel : Returns the label of the CD/DVD currently in the specified drive on the stack.

input : The full path to the root of the CD/DVD-ROM drive, so for example "E:\".
output : The full volume label of the disc in the drive. If there is no disc in the
drive, or there is some other error, the function will return
"DVDGetLabel_error" on the stack.

DVD_CheckDrive : Checks if the specified drive is a CD/DVD-ROM drive.

input : The full path to the root of the CD/DVD-ROM drive, so for example "E:\".
output : If the drive is a CD/DVD-ROM drive, the function will return "CDROM" on the
stack. (For other possible outputs, see the function code.)

DVD_Unload : Unloads dlls used in other DVD functions. Call this function from .onGUIEnd
to prevent .dll files from remaining in the user's temp folder. No input or
output.
*/
</highlight-nsis>
== The Functions ==
<highlight-nsis>
Function DVD_GetNextDrive
Exch $R1
Push $R0
Push $R2
Push $R3
Push $R4

;get all drives (return to $R0, bitwise)
System::Call /NOUNLOAD 'kernel32::GetLogicalDrives() i .r10'
StrCmp $R0 "0" 0 +3 ;if no drives found, error
StrCpy $R1 "ERROR"
goto break

;If no parameter was supplied at all, assume we're starting at A:\.
StrCmp $R1 "" 0 +4
StrCpy $R1 "0"
StrCpy $R4 "0"
goto loop

;get ascii-number of first char in function parameter
System::Call /NOUNLOAD "*(&t1 r11)i.r12"
System::Call /NOUNLOAD "*$R2(&i1 .r11)"
System::Free /NOUNLOAD $R2
IntOp $R1 $R1 - 65

;check if parameter driveletter is between A and Z
IntCmp $R1 0 0 +2
IntCmp $R1 25 +3 +3
StrCpy $R1 ""
goto break

;backup the (asciiconverted) starting driveletter, for detecting when we've cycled the entire alphabet.
StrCpy $R4 $R1

;If a valid parameter was supplied (ie we had a parameter and we survived so far), start at the driveletter directly after the supplied starting driveletter
IntOp $R1 $R1 + 1
StrCmp $R1 26 0 +2 ;if >Z
StrCpy $R1 0 ; return to A

loop:
IntOp $R2 0x01 << $R1
IntOp $R3 $R2 & $R0
;if (0x01<<driveletter & drivesfound) == 0x01<<driveletter (in other words, if there is a drive mounted at this driveletter)
StrCmp $R3 $R2 0 NoDriveHere
;convert asciinumber of driveletter to character
IntOp $R2 $R1 + 65
IntFmt $R2 %c $R2
;get type of drive
System::Call /NOUNLOAD 'kernel32::GetDriveType(t "$R2:\") i .r13'
StrCmp $R3 5 0 NoDriveHere
;type is CDROM
StrCmp $R1 $R4 0 +3 ;if we've cycled the entire alphabet (we ended up at the drive specified in the starting paramater)
StrCpy $R1 "" ; no more CDROM drives found
goto break
StrCpy $R1 "$R2:\" ;else: next CDROM drive found
goto break
NoDriveHere:
StrCmp $R1 $R4 0 +3 ;if we've cycled the entire alphabet
StrCpy $R1 "" ; no CDROM drive found
goto break
IntOp $R1 $R1 + 1 ;increment driveletter
StrCmp $R1 26 0 +2 ;if >Z
StrCpy $R1 0 ; return to A
goto loop
break:

Pop $R4
Pop $R3
Pop $R2
Pop $R0
Exch $R1
FunctionEnd

Function DVD_GetLabel
Exch $R0
Push $R1
Push $R2

;leave function if no parameter was supplied
StrCmp $R0 "" break

;get the label of the drive (return to $R1)
System::Call /NOUNLOAD 'Kernel32::GetVolumeInformation(t r10,t.r11,i ${NSIS_MAX_STRLEN},*i,*i,*i,t.r12,i ${NSIS_MAX_STRLEN})i.r10'
StrCmp $R0 0 0 +3
StrCpy $R0 "DVDGetLabel_error"
goto +2
StrCpy $R0 $R1
break:

Pop $R2
Pop $R1
Exch $R0
FunctionEnd

Function DVD_CheckDrive
Exch $R0
Push $R1
System::Call /NOUNLOAD 'kernel32::GetDriveType(t "$R0") i .r11'
StrCmp $R1 0 0 +2
StrCpy $R0 "UNKNOWN"
StrCmp $R1 1 0 +2
StrCpy $R0 "INVALID"
StrCmp $R1 2 0 +2
StrCpy $R0 "REMOVABLE"
StrCmp $R1 3 0 +2
StrCpy $R0 "FIXED"
StrCmp $R1 4 0 +2
StrCpy $R0 "REMOTE"
StrCmp $R1 5 0 +2
StrCpy $R0 "CDROM"
StrCmp $R1 6 0 +2
StrCpy $R0 "RAMDISK"
Pop $R1
Exch $R0
FunctionEnd

Function DVD_Unload
Push $R0
System::Call 'kernel32::GetLogicalDrives() i .r10 ? u'
Pop $R0
FunctionEnd
</highlight-nsis>

[[Category:System Related Functions]]

DVD functions

2008-07-26T00:26:37Z

Message:

{{PageAuthor|Message}}

== Description ==
Because the [[CD-Rom plugin]] is unable to read any data from DVDs, these functions are meant as a replacement with two primary functions: Finding CD/DVD-ROM drives in the user's system and reading CD/DVD-ROM disc labels.
== How To Use ==
<highlight-nsis>/* --------------------------------

DVD functions - a replacement for the CD-ROM plugin for NSIS
Created by Message, 2007

Usage example:
push "" ;push input to stack
call DVD_GetNextDrive ;call function
pop $0 ;pop output from stack

push $0 ;push input to stack
call DVD_GetLabel ;call function
pop $1 ;pop output from stack

call DVD_Unload ;unload from memory

DVD_GetNextDrive : Finds the first/next CD/DVD-ROM drive and returns its full path on the stack.

input : The function will search for the first CD/DVD drive AFTER this specified
drive letter. So with input "C:\" the function will start searching at D:\.
Only the first character of the input is used, so it should be a Capital
letter from A to Z.
If the input does not start with A-Z, the function returns an empty string
("") on the stack.
If the input is empty, the function starts scanning at A:\.
If the function reaches Z:\, it will continue searching at A:\.
output : The full path of the first CD/DVD-ROM drive the function found, for example
"E:\".
If the function could not find any CD/DVD-ROM drive after (and before) the
specified input drive, it will return an empty string ("") on the stack.
If Windows could not find any drives at all (either CD-ROM or otherwise),
the function returns "ERROR". This should never happen.

DVD_GetLabel : Returns the label of the CD/DVD currently in the specified drive on the stack.

input : The full path to the root of the CD/DVD-ROM drive, so for example "E:\".
output : The full volume label of the disc in the drive. If there is no disc in the
drive, or there is some other error, the function will return
"DVDGetLabel_error" on the stack.

DVD_CheckDrive : Checks if the specified drive is a CD/DVD-ROM drive.

input : The full path to the root of the CD/DVD-ROM drive, so for example "E:\".
output : If the drive is a CD/DVD-ROM drive, the function will return "CDROM" on the
stack. (For other possible outputs, see the function code.)

DVD_Unload : Unloads dlls used in other DVD functions. Call this function from .onGUIEnd
to prevent .dll files from remaining in the user's temp folder. No input or
output.
*/
</highlight-nsis>
== The Functions ==
<highlight-nsis>
Function DVD_CheckDrive
Exch $R0
Push $R1
System::Call /NOUNLOAD 'kernel32::GetDriveType(t "$R0") i .r11'
StrCmp $R1 0 0 +2
StrCpy $R0 "UNKNOWN"
StrCmp $R1 1 0 +2
StrCpy $R0 "INVALID"
StrCmp $R1 2 0 +2
StrCpy $R0 "REMOVABLE"
StrCmp $R1 3 0 +2
StrCpy $R0 "FIXED"
StrCmp $R1 4 0 +2
StrCpy $R0 "REMOTE"
StrCmp $R1 5 0 +2
StrCpy $R0 "CDROM"
StrCmp $R1 6 0 +2
StrCpy $R0 "RAMDISK"
Pop $R1
Exch $R0
FunctionEnd

Function DVD_Unload
Push $R0
System::Call 'kernel32::GetLogicalDrives() i .r10 ? u'
Pop $R0
FunctionEnd

Function DVD_GetLabel
Exch $R0
Push $R1
Push $R2

;leave function if no parameter was supplied
StrCmp $R0 "" break

;get the label of the drive (return to $R1)
System::Call /NOUNLOAD 'Kernel32::GetVolumeInformation(t r10,t.r11,i ${NSIS_MAX_STRLEN},*i,*i,*i,t.r12,i ${NSIS_MAX_STRLEN})i.r10'
StrCmp $R0 0 0 +3
StrCpy $R0 "DVDGetLabel_error"
goto +2
StrCpy $R0 $R1
break:

Pop $R2
Pop $R1
Exch $R0
FunctionEnd

Function DVD_GetNextDrive
Exch $R1
Push $R0
Push $R2
Push $R3
Push $R4

;get all drives (return to $R0, bitwise)
System::Call /NOUNLOAD 'kernel32::GetLogicalDrives() i .r10'
StrCmp $R0 "0" 0 +3 ;if no drives found, error
StrCpy $R1 "ERROR"
goto break

;If no parameter was supplied at all, assume we're starting at A:\.
StrCmp $R1 "" 0 +4
StrCpy $R1 "0"
StrCpy $R4 "0"
goto loop

;get ascii-number of first char in function parameter
System::Call /NOUNLOAD "*(&t1 r11)i.r12"
System::Call /NOUNLOAD "*$R2(&i1 .r11)"
System::Free /NOUNLOAD $R2
IntOp $R1 $R1 - 65

;check if parameter driveletter is between A and Z
IntCmp $R1 0 0 +2
IntCmp $R1 25 +3 +3
StrCpy $R1 ""
goto break

;backup the (asciiconverted) starting driveletter, for detecting when we've cycled the entire alphabet.
StrCpy $R4 $R1

;If a valid parameter was supplied (ie we had a parameter and we survived so far), start at the driveletter directly after the supplied starting driveletter
IntOp $R1 $R1 + 1
StrCmp $R1 26 0 +2 ;if >Z
StrCpy $R1 0 ; return to A

loop:
IntOp $R2 0x01 << $R1
IntOp $R3 $R2 & $R0
;if (0x01<<driveletter & drivesfound) == 0x01<<driveletter (in other words, if there is a drive mounted at this driveletter)
StrCmp $R3 $R2 0 NoDriveHere
;convert asciinumber of driveletter to character
IntOp $R2 $R1 + 65
IntFmt $R2 %c $R2
;get type of drive
System::Call /NOUNLOAD 'kernel32::GetDriveType(t "$R2:\") i .r13'
StrCmp $R3 5 0 NoDriveHere
;type is CDROM
StrCmp $R1 $R4 0 +3 ;if we've cycled the entire alphabet (we ended up at the drive specified in the starting paramater)
StrCpy $R1 "" ; no more CDROM drives found
goto break
StrCpy $R1 "$R2:\" ;else: next CDROM drive found
goto break
NoDriveHere:
StrCmp $R1 $R4 0 +3 ;if we've cycled the entire alphabet
StrCpy $R1 "" ; no CDROM drive found
goto break
IntOp $R1 $R1 + 1 ;increment driveletter
StrCmp $R1 26 0 +2 ;if >Z
StrCpy $R1 0 ; return to A
goto loop
break:

Pop $R4
Pop $R3
Pop $R2
Pop $R0
Exch $R1
FunctionEnd
</highlight-nsis>

[[Category:System Related Functions]]