https://github.com/WilliamHackmore/linuxgems/blob/master/cheat_sheet.org.sh
# cheat_sheet.org
# (C) William Hackmore, 2010
# The contents of this file are released under the GNU General Public License. Feel free to reuse the contents of this work, as long as the resultant works give proper attribution and are made publicly available under the GNU General Public License.
# Last updated 8/14/2012
# Best viewed in emacs org-mode.
View the manual for target command
man [command]
Get help with a target command (probably the same as above, but not always):
[command] -h
In case you forget the name of a command, print possible commands relating to [guess]:
apropos [guess]
View index of help pages:
info
Print current working directory:
pwd
Show files in current directory:
ls
Show maximum information about all files, including hidden:
ls -a
Recurse into subdirectories and list those as well:
ls -r
Move/rename a file or directory (be careful that you don't move the source over a destination with the same name):
mv [source] [destination]
Delete target forever (be very careful), use -r recursive flag for directories:
rm [target]
Copy file or directory:
cp [source] [destination]
Mount filesytem:
mount /dev/[device name] /media/[device name]
Unmount:
umount /media/[device name]
Forensically clone filesystems and do other low-level operations on files. Very dangerous:
dd
Work with filesystems and partitions. (Easier, still quite dangerous):
fdisk
Execute command as an administrator (dangerous, but necessary for system administration tasks):
sudo [command]
Become system administrator:
sudo -s
Quit system administration:
exit
Check distro repositories for software updates:
sudo apt-get update
Download and install updates (update first):
sudo apt-get upgrade
Search for package in the repositories:
apt-cache search [keyword]
Get more detail on one specific package:
apt-cache show [package name]
Download and install a package:
sudo apt-get install [package name]
View the output of a command in a more convenient format:
[command] | less
Print a file in terminal:
cat [file]
Find files matching [filename]:
locate [filename]
Search through [filename] for matches to [phrase]:
grep [phrase] [filename]
Search through output of a command for [phrase]:
[command] | grep [phrase]
List all running processes:
ps -e
Standard system monitor showing a more extensive view of all processes and system resources:
top
Like top, but with a better, cleaner interface:
htop
Stop a process from using all system resources and lagging computer:
nice [process name]
Kill misbehaving process (use sparingly, last resort, try 'nice' command first):
pkill [process name]
Make a simple compressed backup of a file or directory:
tar -cvzf [backup output.tgz] [target file or directory]
Open a compressed .tgz or .tar.gz file:
tar -xvf [target.tgz]
Encrypt a file:
gpg -o [outputfilename.gpg] -c [target file]
Decrypt a file:
gpg -o [outputfilename] -d [target.gpg]
Zip and encrypt a directory simultaneously:
gpg-zip -o encrypted-filename.tgz.gpg -c -s file-to-be-encrypted
Current user's home directory:
~/
Current directory:
./
Parent directory:
../
Or even (Two parent directories down):
../../
All files in target directory. (Be very careful.):
/*
Redirect output of one command into the input of another with a pipe:
[command 1] | [command 2]
Or even:
[command 1] | [command 2] | [command 3]
Redirect output to a file:
[command] > file
Or:
[file] > [file]
Or even, to redirect in a different direction:
[file] < [file]
Append output rather than writing over the target file:
[file/command] >> [file]
Works like |, but it writes output to both target and terminal:
tee [target]
Wait until [command 1] is finished to execute [command 2]
[command 1] ; [command 2]
Or even:
[command 1] ; [command 2] ; [command 3]
Zero or more characters:
*
Matches "phrase" and any number of trailing characters:
phrase*
Matches any incidences of "phrase" with any trailing or leading chars:
*phrase*
Matches any one char:
?
Matches any of the characters listed inside brackets:
[chars]
Matches a range of chars between a-z:
[a-z]
Configure network interfaces:
ifconfig
Configure wireless network interfaces:
iwconfig
Connect to a remote server.
ssh [username]@[ipaddress]
Forward x from target to current machine (Get a remote desktop. Very obscure and very useful):
ssh -x [username]@[ipaddress]
Copy files over the network from one machine to another:
scp [source filename]:[username]@[ipaddress] [target filename]:[target username]@[target ipaddress]
Copy only changes between files or directories (super efficient way to sync directories, works either locally or with remote
servers using username@ipaddress:optionalport, just like ssh):
rsync [source] [target]
Check to see if target is online and responding
ping [ip address]
View network route to target:
traceroute6 [ip address]
Network Monitor
netstat
Manage standard linux firewall (advanced users only)
iptables
Scan this machine to check for open ports:
nmap 127.0.0.1
Listen for input from network on [recieving port], dump it to a file (possibly insecure):
netcat -l [recieving port] > file_copied
Pipe the output of a command to a target ip and port over the network:
[command] | netcat -w [number of seconds before timeout] [target ip] [target port]
Use tar to compress and output a file as a stream, pipe it to a target ip and port over the network:
sudo tar -czf - [filename] | netcat -w [number of seconds before timeout] [target ip] [target port]
Change owner of a file or directory:
chown
Change privileges over file or directory:
chmod
Create a new user:
adduser
Change user privileges (be very careful with this one):
usermod
Delete user"
deluser
Print groups:
groups
Create a new group:
groupadd
Change group privileges:
groupmod
Delete group:
delgroup
Temporarily become a different user:
su [username]
Print usernames of logged in users:
users
Write one line to another user from your terminal:
talk
Interactive talk program to talk to other users from terminal:
ytalk
View what processes are using what files:
lsof
View the differences between two files:
diff [file 1] [file 2]
Output the top -n lines of [file]:
head -n [number of lines] [file]
Like head, but it outputs the last -n lines:
tail
Checksum a file:
md5sum [file]
Checksum every file in a directory:
md5deep [directory]
Checksum a file (safer algorithm with no hash collisions):
sha1sum
Same operation as md5deep, but using sha1:
sha1deep
Call [command] every -n seconds, and display output:
watch -n [number of seconds] [command]
Execute [command], print how long it took:
time [command]
View files in home from largest to smallest:
du -a ~/ | sort -n -r | less
remove spaces from filenames in current directory
rename -n 's/[\s]/''/g' *
change capitals to lowercase in filenames in current directory
rename 'y/A-Z/a-z/' *
Print full date and time:
date
Print the hostname of this machine:
echo $HOSTNAME
Print information about current linux distro:
lsb_release -a
Print linux kernel version:
uname -a
Print information about kernel modules:
lsmod
Configure kernel modules (never do this):
modprobe
View Installed packages:
dpkg --get-selections
Print environment variables:
printenv
List hardware connected via PCI ports:
lspci
List hardware connected via USB ports:
lsusb
Print hardware info stored in BIOS:
sudo dmidecode
Dump captured data off of wireless card:
dumpcap
Dump info about keyboard drivers:
dumpkeys
Add a Personal Package Archive from Ubuntu Launchpad:
add-apt-repository
Install a .deb file from command line:
sudo dpkg -i package.deb
update pip (Python package manager):
pip install -U pip
search pip repos
pip
create a virtual python environment
virtualenv [dirname] --no-site-packages
connect to a virtual python environment
source [dirname]/bin/activate
disconnect from a python environment:
deactivate
install package into virtual python environment from outsie:
pip install [packagename]==[version_number] -E [dirname]
export python virtual environment into a shareable format:
pip freeze -E [dirname] > requirements.txt
import python virtual environment from a requirements.txt file:
pip install -E [dirname] -r requirements.txt
Start a new git project:
git init
Clone a git (target can be specified either locally or remotely, via any number of protocols):
git clone [target]
Commit changes to a git:
git commit -m "[message]"
Get info on current repository:
git status
Show change log for current repository:
git log
Update git directory from another repository:
git pull [target]
Push branch to other repository:
git push [target]
Create a new branch:
git branch [branchname]
Switch to target branch:
git checkout [branchname]
Delete a branch:
git branch -d [branchname]
Merge two branches:
git merge [branchname] [branchname]
clone a virtual machine (this works, it's been tested):
vboxmanage clonehd [virtual machine name].vdi --format VDI ~/[target virtual machine name].vdi
mount a shared virtual folder:
you need to make sure you have the right kernel modules. You can do this with modprobe, but this package works instead in a ubuntu-specific way.
sudo apt-get install virtualbox-ose-guest-utils
sudo mount -t vboxsf [name of Shared folder specified in Virtualbox] [path of mountpoint]
Get help:
help
Show databases:
show databases;
Choose a database to use:
use [database name here];
Show database schema:
show tables;
Delete database:
DROP DATABASE [databasename];
New database:
CREATE DATABASE [databasename];
Create a new user:
CREATE USER [username@localhost] IDENTIFIED BY '[password]' ;
Show users:
select * from mysql.user;
Delete a user:
delete from mysql.user WHERE User='[user_name]';
Give user access to all tables (make them root). the "%" means that they can sign in remotely, from any machine, not just localhost.:
grant all privileges on . to someusr@"%" identified by '[password]';
give certain privileges to a user on a certain database:
grant select,insert,update,delete,create,drop on [somedb].* to [someusr]@["%"] identified by '[password]';
Tell mysql to use new user priv policies:
flush privileges;
change user password:
use mysql;
update user set password='[password]'('[newpassword]') where User='[user_name]' ;
mysql command line args:
export text file with commands to rebuild all mysql tables:
mysqldump [databasename] > [dumpfilename.txt]
restore from a dump:
mysql -u [username] -p < [dumpfilename.txt]
dump entire database:
mysqldump -u [username] -p --opt [databasename] > [dumpfile.sql]
restore from entire database dump:
mysql -u [username] -p --database=[databasename] < [dumpfile.sql]