Linux Notes

Basic
cd - change directory
chmod - change access permission- r=4 w=2 x=1. U G O. 777 means Users, groups and others have all permissions.
clear - clears terminal screen
comm - compare two sorted files line by line
cp - copy one or more files to another location ie. cp file1 dir2
cal - display calendar
dir - briefly list directory contents
date - display or change the date & time
ftp - change to binary mode (bin) and hash (hash) to see download bar. Then navigate to directory using cd, then get file using GET command (or mget to get multiple)
ifconfig - configure a network interface
man - help manual
mkdir - create folder
mv - move or rename files
passwd - modify a user password
rm - remove files
rmdir - removes a directory, rmdir –r removes a directory with files in
touch - change file timestamps/also creates a file and timestamps it
tar - tape archiver

COMMANDS:
# Week 1 #
ps –ef | wc –l
rpm –qa | wc –l
pwd
ls –ail
ls –i
# Week 2 #
man who
> - redirect STDOUT to file
>> - redirect STDOUT, and append data to EOF
< - redirect STDIN from file
echo $PATH
mount -t iso9660 -r /dev/cdrom /mnt/cdrom
umount /mnt/cdrom
chmod [value] [filename]
chown
chgrp
# Week 6 #
ftp [site]
bin
hash
get/mget

## Vi Commands ##
dd - delete entire line
4dd - delete 4 lines
yy - copy lines into buffer
4yy - copy 4 lines
p - paste buffer below current line
P - paste buffer above current line
x - delete character at cursor
5x - delete 5 characters at cursor
ZZ - save file and quit from command mode
b3yy - copy 3 lines to buffer "b"
bp - paste the "b" buffer
q! - quit without saving
/ - search
/abcd - search for the first occurence of abcd
set - show vi environment variables.
Text Mode
i - insert @ cursor
a - append to right of cursor
A - append to end of line
o - open new line before cursor
O - open new line after cursor
R - replace characters at cursor

# Week 7 #
head [-num of lines] - show first 10 lines of file
tail [-num of lines] - show last 10 lines

# Week 8 #
GREP
UNIQ - removes dupe lines from a sorted file
COMM - compares two sorted files line by line
DIFF - find the difference between two files
SED - Stream editor, basic text transformations

# Week 11 #
bash
sh
csh
telinit q
startx
mail [user]

# Week 13 #
umask [xXx]
rpm -qa - query all
rpm -qi - query information
ntsysv
netstat -a
who -iH
tar -cvf [name] [files/dirs inside] - create verbose file
tar -tf [name] - display contents of tar file
tar -xvf [name of tar file] - extract tar