Read-only access to FAT32/NTFS files w/ write locks?

[Matt]

Hello,

In my application that I'm writing in C++ (and maybe Java),
specifically the cygwin flavor of C++, I want to be able to open any
existing files in FAT32 or NTFS file systems (in Windows XP) for
read-only purposes. In particular, I want my program to
unconditionally be able to read-only open any file--and be able to
read all the contents from said fail--which has been marked with any
sort of "exclusionary" lock, including write locks or any other kind
of locks.

Is this possible? Are there any "exclusionary" locks or scenarios
where in WinXP (with either FAT32 or NTFS files) that might prevent
another process from opening a file in read-only mode?

The only case I have experience: using cygwin to unset all file
permissions (including the "read" bit(s)) in an NTFS file system, in
which case non-Administrator processes (presumably) will not be able
to read the file.

Thanks for any help,
-Matt

 

[Pegasus \(MVP\)]

Hello,

In my application that I'm writing in C++ (and maybe Java),
specifically the cygwin flavor of C++, I want to be able to open any
existing files in FAT32 or NTFS file systems (in Windows XP) for
read-only purposes. In particular, I want my program to
unconditionally be able to read-only open any file--and be able to
read all the contents from said fail--which has been marked with any
sort of "exclusionary" lock, including write locks or any other kind
of locks.

Is this possible? Are there any "exclusionary" locks or scenarios
where in WinXP (with either FAT32 or NTFS files) that might prevent
another process from opening a file in read-only mode?

The only case I have experience: using cygwin to unset all file
permissions (including the "read" bit(s)) in an NTFS file system, in
which case non-Administrator processes (presumably) will not be able
to read the file.

Thanks for any help,
-Matt

Windows has several mechanisms that will prevent you from
opening a file, either in read-only mode or in read/write mode.
The file could be locked (e.g. the paging file, or the registry
files), or the current account could have insufficient access
rights to that file. This is so by design.

 

[Maxim S. Shatskih]

Snapshots help a lot.

 

[Kristo]

Matt wrote:
[a Windows-specific question]

This is off-topic for clc++. Followups set.

Kristo