Get File Size using the system plugin

From NSIS Wiki

Author: Joel (talk, contrib)

[edit] The Script

; My first script that uses system.dll :D
; Input a file to retrive is version
; to finish the script, just need the division with fractional decimals. :(
 
OutFile "FileSize.exe"
Name "Get File Size"
Caption "Get File Size"
XPStyle "on"
 
Function "FileSize"
Exch $R0 ;Grab the Inputed path file
System::Call 'kernel32::_lopen(t "$R0", i 0) i .r0' ; Call the API to open the
file
System::Call 'kernel32::GetFileSize(i $0, i) i .r1' ; Call API to read file
size
IntOp $2 $1 / 1024 ; $1 is in bytes, let's converted to KBs
MessageBox MB_OK|MB_ICONINFORMATION "File: $R0 $\r$\nSize: $2 KB" ; Display
the info.
System::Call 'kernel32::_lclose(i $0) i' ; API to close the opened file
Quit ; Close NSIS
FunctionEnd
 
Function ".onInit"
Push "${NSISDIR}\makensis.exe" ; Input full path of the file
Call "FileSize" ; Call the function
FunctionEnd
 
Section "-boo"
;
SectionEnd