i was changing rwx privileges for a certain folder temporarily, and went back as regular user after i did this from root. then i did something and the prompt said, "MIT MAGIC COOKIE access denied..." or something like that. i can't really remember.
what does this mean anyway? what i wanted done was done anyway, but that line came out. (i think i was gonna read/write to a file that root owned, and i was logged in as regular user.) kinda pretty dumb, but i just wanna know what it means.
It seems to have with xauth to do. The X server uses a system of pluggable modules to determine which clients are allowed to connect, and one of these modules uses MIT-MAGIC-COOKIEs. I'm not sure exactly what would have caused this, but almost certainly, it is related to it.
ahh, like when i'm trying to open a certain file that which i don't have rights to, with a gui-based editor thru the console and so that popped out?
i read somewhere that the concept in x windows is like a server-client relationship. unlike windoze window system. that's why it's more stable, and so anytime the x windows becomes unstable, you could always kill it without the "hangs." am i making sense here? anyway, it also says that these cookies are created for those who want to connect to x... something like that...
Yeah, that's about it. The X server runs like any other process in the system and all programs that wish to display a window connects to it as a client. That is also where these cookies come in. When the display manager logs you in, it creates a cookie which it gives to the X server and puts in the .Xauthority file in your home directory, which is created so that only you have read permission to it. The cookie works like a password; the clients must specify it in order to connect to the X server. That is to prevent other users from displaying windows on your X server, disturbing you.
The thing is that not only does this create a more stable and flexible architecture, but the X server also listens to connections over the network, which means that you can run programs on other computers and make them display windows on your local X server, making it appear as if they are running locally. So, instead of telnetting to another machine, you can start an xterm directly on that machine and making it display the window on the machine that you're sitting by.
Of course, it's not completely stable. The X server still accesses the hardware, and if it were to make something that would make the hardware hang, then the system is hung nonetheless, but it happens pretty seldomly.
kewl! thanks for the info dolda...