



                1960's 
                
                
                MUTLIX -> Unix  (PDP 7)
                
                a lot of collages 
                
                ----------------------------------
                
                Unix/Linux are a collection of small programs
                
                ls -r (-r mean recursive)
                sort -r (-r reverse)
                
                cat /etc/password | cut -f1 -d: | sort -r | head -5 
                
                1970's
                
                SVR4 -> a standard OS release (AT&T) 
                
                
                Appl
                
                POSIX 
                system commands <- open a file, read a records, etc
                
                Kernel Code to manage the hardware
                  (disk driver, network card driver, etc)
                
                --------------------------------------------------
                IBM -> AIX (IBM version of SVR4)     Unix current is Vendor 
                HP -> HP-UX 
                Sun -> Solaris
                ....  
                
                1990's
                
                Linus -> reverse engeneered the AT&T Kernel and made it
                           open-source
                
                now we have Linux on anything
                
                then a number of groups created "distributions"
                which are the kernel and a set of tools, and commands
                
                -------------------------------------
                
                for example:
                
                Unix has a pager command name: pg
                Linux has a pager command name: more, less
                
                
                ----------------------------------------------------
                
                in 1960's 
                
                to use the OS you were a programmer
                and worked in the source code
                
                
                in 1970's Steven Bourne wrote a program
                to inteact w/ the OS - Shell
                
                When I logon I get program running, this is my shell
                the Shell will take my commands (and parse them)
                then try to run them for me
                
                the first shell (the Bourne Shell) 
                is named: sh
                
                then David Korn create an updated Shell w/
                history, command subsutation, and more
                
                this shell is named: ksh (only on Unix)
                
                there is a C-Shell: csh 
                
                Linux come with bash (Bourne Again Shell)
                
                for security I can restrict a user w/ rcsh
                or trust a user w/ tcsh shells
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
