Introduction to Computer Organization & Systems Spring 2018 Introduction to Computer Organization & Systems UNIX/Linux Command Line Topics: UNIX command line C - everything

Unix Passwords Help Changing about a command passwd whoami finger and the .plan file Help about a command man cmdName apropos cmdName which cmdName ;gives path to the application

Unix Directories Seeing, manuvering, creating cd /path/to/new/directory pwd ls [-a –l] mkdir dirName rmdir dirName rm –r dirName pushd . popd

Unix Files Moving, deleting Viewing Permissions cp src dest rm fileName Viewing more fileName cat fileName1 fileName2 Permissions ls –l chmod 777 fileName

Unix Processes What’s running? ps ;only your processes ps –a ;all processes PID TTY TIME CMD 33129 ttys000 0:00.02 -bash 33178 ttys000 0:00.00 man builtin 33186 ttys000 0:00.00 /usr/bin/less -is 33131 ttys001 0:00.01 -bash 33130 ttys002 0:00.02 –bash

Kill kill command is used to stop a running process A user can kill all his process. A user can not kill another user’s process. A user can not kill processes System is using. A root user* can kill System-level-process and the process of any user. * the root is the administrator

Kill kill -9 pid ;kill process pid other ways to kill kill by name pkill a.out ;kill all processes named a.out kill on the command line ^c ;hold down control key and press the c key ;kills currently running process

More Unix Shells Environmental variables (capitalization counts!) Echo $ENV $PATH .bashrc and.bash_profile files alias changing $PATH using source to act on changes to the file Pipes using the | operator to connect programs

More Unix Redirection History using > and >> to redirect stdout to a file > to overwrite >> to append using &> to redirect stdout and stderr to a file gcc –g -o ex1 ex1.c > err.txt &> err.txt using < to redirect stdin from file History the ! operator