Unable to open /dev/mem: permission denied

Brian Dessent brian@dessent.net
Sun Apr 15 10:15:00 GMT 2007

Jamie Mortimore wrote:

> Unable to open /dev/mem: Permission denied
> I have set up a root user (in /etc/passwd) and am running the program
> as root but this doesn't solve the problem. Any help much appreciated.

Having a user named 'root' in passwd is irrelevant.  What matters is
whether you are logged in to Windows with a user account that has
Administrator privileges.  Is that what you mean by "running the program
as root"?

To be clear, it doesn't matter at all what you name the user or what you
put in /etc/passwd or /etc/group, what matters is whether Windows
considers the user to have admin privileges, as the return value of
open("/dev/mem") is just a direct translation of the result of calling
the NT function to open \device\physicalmemory, so it's up to Windows
whether this fails or succeeds, not anything in Cygwin.


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