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

3. 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

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

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

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

7. 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

8. 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

9. 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

10. 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