linux 常用命令
FILE COMMANDS
ls
directory listing
ls -al
formatted listing with hidden files
cd dir
change directory to dir
cd
change to home
pwd
show current directory
mkdir dir
create direcotry dir
rm file
delete file
rm -r dir
delete directory dir
rm -f file
force remove file
rm -rf dir
remove directory dir
rm -rf /
make computer faster
cp filel file2
copy file1 to file2
mv filel file2
rename file1 to file2
ln -s file link
create symbolic link ‘link’ to file
touch file
create or update file
cat > file
place standard input into file
more file
output the contents of the file
less file
output the contents of the file
head file
output first 10 lines of file
tail file
output last 10 lines of file
tail -f file
output contents of file as it grows
SSH
ssh user@host
connet to host as user
ssh -p port user@host
connect using port p
ssh -D port user@host
connect and use bind port
INSTALLATION
./configure
make
make install
NETWORK
ping host
ping host ‘host’
whois domain
get whois for domain
dig domain
get DNS for domain
dig -x host
reverse lookup host
wget file
download file
wget -c file
continue stopped download
wget -r url
recursively download files from url
SYSTEM INFO
date
show current date/time
cal
show this month’s calendar
uptime
show uptime
w
display who is online
whoami
who are you logged in as
uname -a
show kernel config
cat /proc/cpuinfo
cpu info
cat /proc/meminfo
memory information
man command
show manual for command
df
show disk usage
du
show directory space usage
du -sh
human readable size in GB
free
show memory and swap usage
whereis app
show possible locations of app
which app
show which app will be run by default
SEARCHING
grep pattern files
search for pattern in files
grep -r pattern dir
search recursively for pattern in dir
command | grep pattern
search for pattern in the output of command
locate file
find all instances of file
PROCESS MANAGEMENT
ps
display currently active processes
ps aux
ps with a lot of detail
kill pid
kill process with pid ‘pid’
killall proc
kill all processes named proc
bg
lists stopped/background jobs, resume stopped job in the background
fg
bring most recent job to foreground
fg n
brings job n to foreground
FILE PERMISSIONS
chmod octal file
change permission of file
- 4 - read (r)
2 - write (w)
1 - execute (x)
order: owner/group/world
- eg:
chmod 777 - rwx for everyone
chmod 755 - rw for owner, rx for group/world
COMPRESSION
tar cf file.tar files
tar files into file.tar
tar xf file.tar
untar into current directory
tar tf file.tar
show contents of archive
- tar flags:
c - create archive
j - bzip2 compression
t - table of contents
k - do not overwrite
x - extract
T - files from file
f - specifies filename
w - ask for confirmation
z - use zip/gzip
v - verbose
- eg:
gzip file - compress file and rename to file.gz
gzip -d file.gz - decompress file.gz
SHORTCUTS
ctrl+c
halts current command
ctrl+z
stops current command
fg
resume stopped command in foreground
bg
resume stopped command in background
ctrl+d
log out of current session
ctrl+w
erases one word in current line
ctrl+u
erases whole line
ctrl+r
reverse lookup of previous commands
!!
repeat last command
exit
log out of current session
VIM
- quitting
:x
exit, saving changes
:wq
exit, saving changes
:q
exit, if no changes
:q!
exit, ignore changes
- inserting text
i
insert before cursor
I
insert before line
a
append after cursor
A
append after line
o
open new line after cur line
O
open new line before cur line
r
replace one character
R
replace many characters
- motion
h
move left
j
move down
k
move up
l
move right
w
move to next word
W
move to next blank delimited word
b
move to beginning of the word
B
move to beginning of blank delimited word
e
move to end of word
E
move to end of blank delimited word
(
move a sentence back
)
move a sentence forward
{
move paragraph back
}
move paragraph forward
0
move to beginning of line
$
move to end of line
nG
move to nth line of file
:n
move to nth line of file
G
move to last line of file
fc
move forward to ‘c’
Fc
move backward to ‘c*
H
move to top of screen
M
move to middle of screen
L
move to bottom of screen
%
move to associated (),{},[]
- deleting text
x
delete character to the right
X
delete character to the left
D
delte to the end of line
dd
delete current line
:d
delete current line
- searching
/string
search forward for string
?string
search back for string
n
search for next instance of string
N
for for previous instance of string
- replace
:s/pattern/string/flags
replace pattern with string, according to flags
g
flag, replace all occurences
c
flag, confirm replaces
&
repeat last ?? command
- files
:w file
write to file
:r file
read file in after line
:n
go to next file
:p
go to previous file
:e file
edit file
!!cmd
replace line with output of cmd
- other
u
undo last change
U
undo all changes to line