On Aug 26, 2009, at 5:41 PM, Bhaktavatsalam Nallanthighal wrote: > > Hi, > > Can anyone tell me which part of the latest linux kernel gives > control to a shell? More aptly, at which point exactly does the linux
No part of the kernel itself gives control to a shell. The shell is a separate program which is built against the kernel libraries. > kernel[the shell?] ask the user for a username and password? This is actually handled by a completely different program called "login." Login simply checks against the user store, from PAM, LDAP, MySQL Store, etc. login then runs a shell in user mode. In systems where graphical logins are performed, this login program is replaced (or rather, another program is run instead) called xlogin (IIRC, I could have got the name run) which is run by xinit. So in other words.... Let's start from the ground up. boot: initramfs starts, kernel is loaded and the init script is started. init: init system runs a whole mess of shell scripts which start services, networking, databases, and a million other things. It's all very complex and confusing and generally speaking no person can comprehend the whole thing all at once. You have to think about each piece individually otherwise your brain will turn to jelly and then a splode. login: in a serial terminal system the login program is run. A user logs in, a shell is started. OR xinit: xorg is started. The GUI starts, mouse shows up, and a whole lot of other magical things happen. xlogin: xlogin starts a graphical login screen which is kind of like the normal login only it then passes that user on to the rest of X and makes the desktop, windows, buttons, icons, and all that stuff. And that's a rough sketch of that. Not 100% accurate, but just vague enough to be mostly true. HTH a bit. From here you can ask more specific questions and get real answers hopefully. Registered Linux Addict #431495 For Faith and Family! | John 3:16! http://www.fsdev.net/ --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Linux Users Group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] For more options, visit our group at http://groups.google.com/group/linuxusersgroup -~----------~----~----~----~------~----~------~--~---
