Create a locked file (Views: 102)
I was using temporary files on the root of the disk, but the user could try to modify it when my application was open and I didn't want that. Here's how to prevent it.
There are two ways of doing that, but one, with the use of Windows' APIs (LockFileEx and UnlockFileEx) using the parameter LOCKFILE_EXCLUSIVE_LOCK was not good for my case, so I found that:
Create the file with the OpenFile function and handle it:
hMyLockedFile := OpenFile('c:\variables.dat', ofStruct, OF_CREATE or OF_READWRITE or
Now, you can work with your file, but users cannot change it!
A last comment:
I found that in Win32 SDK Reference, so if you need to know more (and there's more to know: believe me!) you should use it!
MyText: array[0..500] of char;
MyText := 'Mark Halter' + chr(13) + Chr(10) + 'Südstr. 6';
with SA do
nLength := SizeOf(SA);
bInheritHandle := True;
lpSecurityDescriptor := nil;
Hndl := CreateFile('d:\temp\testfile.txt', // filename
GENERIC_READ or GENERIC_WRITE, // read/write access
0, // do not share file
@SA, // Security Attributes
CREATE_ALWAYS, // create file everytime
FILE_ATTRIBUTE_NORMAL, // set normal attributs
OK := WriteFile(Hndl,
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