Linuxコマンド

昔はこれら全て1つ1つがアプリだった。粒度が小さく、基本的には役割分担が明確だったので Unix哲学の象徴だと言える。

略語の意味を示すために説明は英語表記。

シェルコマンド

コマンド	説明
!!	直前に実行したコマンドを実行
[Ctrl] + r	履歴を検索して実行
CMD1 ; CMD2	CMD1 を実行してから CMD2 を実行する
CMD1 && CMD2	CMD1 の終了ステータスが「0」なら CMD2 を実行する
CMD1 || CMD2	CMD1 の終了ステータスが「0」以外なら CMD2 を実行する
CMD1 | CMD2	CMD1 の出力を、CMD2 の入力へと渡すパイプ
>, 1>	標準出力先を指定
>>	標準出力先を指定（追記）
2>	標準エラー出力先を指定
&>	標準出力先、標準エラー出力先の両方を指定
<< eof	here document（EOF文字が出現するまでの内容を標準入力とする）
vi /etc/profile	全ユーザに共通するシェル環境を設定

コピー＆ペースト

Linux では通常の「クリップボード」に加えて「X・プライマリ・セレクション」も利用できる。

コマンド	説明
ハイライト + ホイールボタン	ハイライト部分を新規にペースト
xclip	clip to X-selections and clipboard

カーネル管理

コマンド	説明
grub-mkconfig	generate a GRUB configuration file
mkinitramfs	initramfs image generator ( Debian )
dracut	initramfs image generator ( RH )
dmesg	display Kernel message ring
lsmod	list Linux Kernel modules
modinfo	show information about a Kernel modules
insmod	insert a Kernel module
rmmod	remove a Kernel module
depmod	generate modules.dep
modprobe	add and remove modules from Kernel

デバイス管理

コマンド	説明
lscpu	list CPU info
dmidecode	dumping a computer's DMI table contents
free	free memory
vmstat	virtual memory statistics
lsblk	list storage, partition infomation
df	disk free on filesystem
du	disk used
lspci	list Peripheral Component Interconnect devices
lsusb	lsit USB devices
lsscsi	list SCSI devices
hwclock	set hardware clock
hdparm	show HDD/SATA/IDE parameters
sdparm	access SCSI mode page
loadkeys	loadkeybords
wodim	write to CD/DVD
growisofs	write iso image to DVD

パーティション管理

コマンド	説明
fdisk	fixed disk. manipulate disk partition table
gdisk	GUID Partition Table (GPT) manipulator
parted	a partition edit program
gparted	GNU partition edit program
partx	show partitions
mkswap	make a Linux swap area
swapon	enable devices and files for swapping
swapoff	disable devices and files for swapping

ファイルシステム管理

コマンド	説明
mke2fs	make an ext2/ext3/ext4 filesystem
tune2fs	adjust tunable filesystem parameters on ext2/ext3/ext4 filesystems
e2fsck	check a Linux ext2/ext3/ext4 file system
mkfs	make a Linux filesystem
fsck	file system check
debugfs	ext2/ext3/ext4 file system debugger
mount	mount a filesystem
umount	unmount a filesystem

システム管理

コマンド	説明
systemctl	system mamager
screen	terminal screen manager
setterm	terminal settings
tmux	?
chvt	change vertual terminal
uptime	Tell how long the system has been running.
uname	show system information
arch	( = uname -m) show system hardware name
hostname	hostname
hostnamectl	mamage hostname
init	system mamager
initctl	?
chkconfig	old way of systemctl
runlevel	show runlevel
update-rc.d	set System-V initial links
sysctl	configure Kernel parameters
ldd	list dynamic dependencies
ldconfig	ldd configure
logger	enter message to system log
journalctl	system log manager
halt	halt, power off, reboot machine
shutdown	shutdown machine
which	locate a command
whereis	locate the binary, source, and manual page files for a command
busybox	command tool box

プロセス管理

コマンド	説明
top	( = htop ) show top processes
pstree	show machine's running processes as tree
ps	show machine's running processes
nice	set program priority
renice	alter program priority
kill	kill process by PID
killall	kill processes by name
pkill	process kill
pgrep	process grep
lsof	list files opened by processes
pidof	process id open file
fuser	identify file opening process
pwdx	pwd for process
jobs	show working jobs
bg	doing job at background
fg	doing job at forgraound
nohup	run command without logout hang up

ユーザ管理

コマンド	説明
last	show a listing of last logged in users
lastlog	reports the most recent login of all users
w / who	show logged-in users
users	show logged-in users
groups	show user's groups
useradd	add a user ( useradd -m -s /bin/bash -G sudo hoge )
usermod	modify a user
userdel	delete a user ( userdel -r hoge )
groupadd	add a group
groupmod	modify a group
groupdel	delete a group
passwd	change user's password
gpasswd	manage group password
newgrp	log in to a new group
chpasswd	change password in batch mode
chage	change / show user's account and password age
chsh	change login shell
pwck	check password file
finger	user's fingerprint
chfn	change user's fingerprint
grpck	check group file
vipw / vigr	edit password / group file
pwconv	convert password file
edquota	edit quota for user disk
write / wall	write a massage to all users
htpasswd	httpd basic authentication
htdigest	httpd digest authentication

ユーザツール

コマンド	説明
id	show user's id
whoami	who am i ?
date	show date
cal	show calendar
set	show shell environment. set >> env
env	show user's enviroment
printenv	(= env) show environment
export	export environment from shell's env to user's env
history	show command history
alias	make alias
unalias	unmake alias
fc	?
su	switch user
sudo	switch user do
sg	switch group
chroot	run command with special root directory
crontab	manage cron
expect	expect response
at	?
script	?
stdbuf	modify buffering
time	show round trip time
watch	run program periodically
sleep	set a moment before run
exit	exit terminal
make	compile file
install	copy files
yes	always say "yes"
xargs	x-arguments
git	git
cvs	cvs
svn	svn
mysql	mysql client / server
mysqldump	mysql dump databases
xl	?
VBoxManage	?
lpadmin	configure cups printers
lpstat	show cups printing status
lp	submit files for printing
lpr	subimt files for printing
cancel	cancel printing job

ファイル / ディレクトリ操作

コマンド	説明
pwd	print working directory
tree	show tee-style directory
ls	list
cd	change directory
find	find files
locate	location of files
updatedb	update database for locate
basename	base name of file
dirname	name of directory
file	show types of files
stat	status of file
lsattr	list file attributes on a Linux second extended file system
chattr	change file attribution
chmod	change mode
chown	change owner of file
chgrp	change owner group
mkdir	make a directory
rmdir	remove direcotory
touch	touch a file
cp	copy
mv	move, change
rm	remove
shred	shred files
ln	make links between files
readlink	show symbolic link
tmpwatch	?
umask	user mask
split	split a file into pieces. 1,000 rows chunk as default
truncate	shrink or expand file
tar	type archive
cpio	(= tar) copy files to and from archives
gzip / gunzip	zip / unzip
mktemp	make temporary file
convmv	convert move
dd	dump datas
pv	pipe viewer
base64	base64 encode / decode
od	dump files in octal and other formats
md5sum / sha1sum	calculate md5 or sha1
iconv	change file encoding
strings	show string parts in data file
uuencode	?
uudecode	?
lhasa	?
unrar	?
pushd	?

テキスト操作

コマンド	説明
echo	display a line of text
tee	write std-output and life
more	viewer
less	viewer
head	show head part of file
tail / tailf	show tail part of file
cat	concatinate
tac	etanitacnoc
nl	with number line
grep	global reguler expression print
uniq	show only uniq part
wc	word count
cut	cut
rev	reverse
seq	sequence
sort	sort lines of text files
tr	translate or delete characters
ex	ex mode of vi
ed	line editor
sed	stream editor
vi	visual editor
awk	patter scanning and processing language
nkf	?
patch	patch a diff file
diff	compare two files line by line
comm	compare two files line by line
cmp	compare two files byte by byte
col	remove \n etc.
column	columnate list
colrm	column remove
expand	expand tab to space
unexpand	space to tab
paste	marge files
join	marge same parts of files
bc	calculator
let	calculate
factor	show factor numbers
expr	evaluate expression
test	?
shuf	shuffle some value
fold	wrap words in lines
pr	for printer format

パッケージ管理

コマンド	説明
apt	advanced packaging tool
dpkg	Debian package manager
dpkg-reconfigure	reconfigure an already installed package
yum	yellodog-linux update manager
rpm	RedHat package manager
rpm2cpio	rpm file to cpio

ネットワーク

コマンド	説明
ss	show sockets
netstat	network status
arp	ip neighbors
ipcalc	ip calculator
ip	internet protocol mnager
route	ip routing table manager
ifconfig	interface configure
iwconfig	interface wireless configure
iwlist	show Wi-Fi access-point
wpa_supplicant	protected Wi-Fi cliant
nmtui	NetworkManager text-user interface
nmcli	NetworkManager command-line interface
iptables	packet filtering tool
ufw	uncomplicated firewall manager
firewall-cmd	firewall manager
ping	send ICMP ECHO_REQUEST
tracepath	show a path to the host
arping	send ARP REQUEST to neighber
ntpq	NTP quary
ntpdate	set the date via NTP
clockdiff	time lag to remote host
ssh	secure shell
ssh-keygen	ssh-key generator
ssh-copy-id	ssh copy id
scp	secure copy
rsync	remote file-copying tool
telnet	?
ftp	file transfer program
sftp	secure ftp
wget	WWW downloader
curl	Client URL Request Library
tcpdump	dump traffic on a network
tshark	?
brctl	?
host	DNS lookup
nslookup	DNS lookup
dig	DNS lookup
whois	show IANA info

ネットワークセキュリティ

コマンド	説明
nmap	Network Mapper
netcat / nc	network investigator
gpg	GNU Privacy Gard
openssl	SSL / TLS tool kit
pwgen	password generator

ネットワークツール

コマンド	説明
mail	send and receive mail
mailq	?
newaliases	mail alias
w3m	WWW monitor
showmount	show NFS server's exports status
rdesktop	remote desktop

TIPS

画像を一括して圧縮

# find /var/www/html/wp-content/uploads/ -name *.jpg | xargs -t -I{} convert {} -sampling-factor 4:2:0 -strip -quality 90 -interlace JPEG -colorspace sRGB {}