POiSON WORLD

alias – Create an alias

awk – Find and Replace text, database sort/validate/index

break – Exit from a loop

builtin – Run a shell builtin

cal – Display a calendar

cse – Conditionally perform a command

cat – Display the contents of a file

cd – Change Directory

cfdisk – Partition table manipulator for Linux

chgrp – Change group ownership

chmod – Change access permissions

chown – Change file owner and group

chroot – Run a command with a different root directory

cksum – Print CRC checksum and byte counts clear Clear terminal screen

cmp – Compare two files

comm – Compare two sorted files line by line

command – Run a command – ignoring shell functions

continue – Resume the next iteration of a loop

cp – Copy one or more files to another location

cron – Daemon to execute scheduled commands

crontab – Schedule a command to run at a later time

csplit – Split a file into context-determined pieces

cut – Divide a file into several parts

date – Display or change the date & time

dc – Desk Calculator

dd – Data Dump – Convert and copy a file

declare – Declare variables and give them attributes

df – Display free disk space

diff – Display the differences between two files

diff3 – Show differences among three files

dir – Briefly list directory contents

dircolors – Colour setup for `ls’

dirname – Convert a full pathname to just a path

dirs – Display list of remembered directories

du – Estimate file space usage

echo – Display message on screen ed A line-oriented text editor (edlin)

egrep – Search file(s) for lines that match an extended expression eject Eject CD-ROM

enable – Enable and disable builtin shell commands

env – Display, set, or remove environment variables

eval – Evaluate several commands/arguments

exec – Execute a command exit Exit the shell

expand – Convert tabs to spaces

export – Set an environment variable

expr – Evaluate expressions

factor – Print prime factors

false – Do nothing, unsuccessfully

fdformat – Low-level format a floppy disk

fdisk – Partition table manipulator for Linux

fgrep – Search file(s) for lines that match a fixed string

find – Search for files that meet a desired criteria

fmt – Reformat paragraph text

fold – Wrap text to fit a specified width.

for – Expand words, and execute commands format Format disks or tapes free Display memory usage

fsck – Filesystem consistency check and repair.

function – Define Function Macros

gawk – Find and Replace text within file(s)

getopts – Parse positional parameters

grep – Search file(s) for lines that match a given pattern

groups – Print group names a user is in

gzip – Compress or decompress named file(s)

hash – Remember the full pathname of a name argument

head – Output the first part of file(s)

history – Command History

hostname – Print or set system name

id – Print user and group id’s

if – Conditionally perform a command

import – Capture an X server screen and save the image to file

info – Help info

install – Copy files and set attributes

join – Join lines on a common field

kill – Stop a process from running

less – Display output one screen at a time

let – Perform arithmetic on shell variables

ln – Make links between files

local – Create variables

locate – Find files

logname – Print current login name

logout – Exit a login shell

lpc – Line printer control program

lpr – Off line print lprint Print a file lprintd Abort a print job lprintq List the print queue

lprm – Remove jobs from the print queue

ls – List information about file(s)

m4 – Macro processor

man – Help manual

mkdir – Create new folder(s)

mkfifo – Make FIFOs (named pipes)

mknod – Make block or character special files

more – Display output one screen at a time

mount – Mount a file system

mtools – Manipulate MS-DOS files

mv – Move or rename files or directories

nice – Set the priority of a command or job

nl – Number lines and write files

nohup – Run a command immune to hangups

passwd – Modify a user password

paste – Merge lines of files pathchk Check file name portability

popd – Restore the previous value of the current directory

pr – Convert text files for printing printcap Printer capability database printenv Print environment variables

printf – Format and print data

ps – Process status

pushd – Save and then change the current directory

pwd – Print Working Directory

quota – Display disk usage and limits

quotacheck – Scan a file system for disk usage

quotactl – Set disk quotas

ram – ram disk device

rcp – Copy files between two machines.

read – read a line from standard input

readonly – Mark variables/functions as readonly remsync Synchronize remote files via email

return – Exit a shell function

rm – Remove files

rmdir – Remove folder(s)

rpm – Remote Package Manager

rsync – Remote file copy (Synchronize file trees) screen Terminal window manager

sdiff – Merge two files interactively

sed – Stream Editor

select – Accept keyboard input

seq – Print numeric sequences

set – Manipulate shell variables and functions

shift – Shift positional parameters

shopt – Shell Options

shutdown – Shutdown or restart linux

sleep – Delay for a specified time

sort – Sort text files

source – Run commands from a file `.’

split – Split a file into fixed-size pieces

su – Substitute user identity

sum – Print a checksum for a file

symlink – Make a new name for a file

sync – Synchronize data on disk with memory

tac – Concatenate and write files in reverse

tail – Output the last part of files

tar – Tape ARchiver

tee – Redirect output to multiple files

test – Evaluate a conditional expression

time – Measure Program Resource Use

times – User and system times

touch – Change file timestamps

top – List processes running on the system

traceroute – Trace Route to Host trap Run a command when a signal is set(bourne)

tr – Translate, squeeze, and/or delete characters

true – Do nothing, successfully

tsort – Topological sort

tty – Print filename of terminal on stdin

type – Describe a command

ulimit – Limit user resources

umask – Users file creation mask umount Unmount a device

unalias – Remove an alias

uname – Print system information

unexpand – Convert spaces to tabs

uniq – Uniquify files

units – Convert units from one scale to another

unset – Remove variable or function names

unshar – Unpack shell archive scripts

until – Execute commands (until error)

useradd – Create new user account

usermod – Modify user account

users – List users currently logged in

uuencode – Encode a binary file

uudecode – Decode a file created by uuencode v Verbosely list directory contents (`ls -l -b’) vdir Verbosely list directory contents (`ls -l -b’)

watch – Execute/display a program periodically

wc – Print byte, word, and line counts

whereis – Report all known instances of a command

which – Locate a program file in the user’s path.

while – Execute commands

who – Print all usernames currently logged in whoami Print the current user id and name (`id -un’)

xargs – Execute utility, passing constructed argument list(s)

yes – Print a string until interrupted

.period – Run commands from a file

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