Linux classic skills

1. process by memory in ascending order: ps-eo & quot; % C: % p: % z: % a & quot; | sort-k5-nr2. view which processes are currently available; view the files opened by the process: ps-A; lsof-pPID3. obtain the current IP address (learn the role of grep, awk, cut) ifconfigeth0 | grep & quot; inetaddr: & quot; | awk & #39; {print $2 }&

1. process sorting by memory from large to small:
Ps-eo "% C: % p: % z: % a" | sort-k5-nr

2. check which processes are currently running; view the files opened by the process:
Ps-A; lsof-p PID

3. get the current IP address (learn the role of grep, awk, and cut)
Ifconfig eth0 | grep "inet addr:" | awk '{print $2}' | cut-c 6-

4. count the frequency of each word and sort it.
Awk '{arr [$1] + = 1} END {for (I in arr) {print arr "\ t" I}' file name | sort-rn

5. display 10 of the most common commands
Sed-e "s/|/\ n/g "~ /. Bash_history | cut-d ''-f 1 | sort | uniq-c | sort-nr | head

6. killing Nginx processes (killing a process)
Ps-ef | grep-v grep | grep nginx | awk '{print $2}' or
For I in 'PS aux | grep nginx | grep-v grep | awk {'print $ 2'} '; do kill $ I; done

7. list the directory size of the current folder, which is displayed in G, M, and K.
Du-B -- max-depth 1 | sort-nr | perl-pe's {([0-9] +)} {sprintf "%. 1f % s ", $1> = 2 ** 30? ($1/2 ** 30, "G"): $1> = 2 ** 20? ($1/2 ** 20, "M"): $1> = 2 ** 10? ($1/2 ** 10, "K"): ($1, "")} e'

Shaw answer: du-hs $ (du-sk./'ls-F | grep/'| sort-nr | awk' {print $ NF }')
But it is not perfect. But remember.

8. Clear linux buffer cache
Sync & echo 3>/proc/sys/vm/drop_caches

9. convert all file names in the current directory to lowercase letters.
For I in *; do mv "$ I" $ (echo $ I | tr A-Z a-z) "; done

10. several methods to eliminate ^ M in vim
1) dos2unformatted filename
2) sed-e's/^ M // 'filename
3) in vim: s/^ M // gc
4) col-bx <dosfile> newfile
5) tr-s "\ r \ n" "\ n" <file> newfile

11. clear all arp caches
Arp-n | awk '/^ [1-9]/{print "arp-d" $1}' | sh

12. bind the arp address of a known Machine
Cat/proc/net/arp | awk '{print $1 "" $4}' | sort-t.-n + 3-4>/etc/ethers

13. perl-ne 'M/^ ([^ #] [^ \ s =] +) \ s * (=. * |)/& printf ("%-35 s % s \ n", $1, $2) '/etc/my. cnf

14. a user is not allowed to use the rm command.

[Root @ localhost pp] # setfacl-m u: pp: 000/bin/rm
[Root @ localhost pp] # su-pp
[Pp @ localhost ~] $ Mkdir test
[Pp @ localhost ~] $ Rm-rf test/
-Bash:/bin/rm: insufficient permissions

Modify back Command

[Pp @ localhost ~] $ Su root
Password:
[Root @ localhost pp] # setfacl-m u: pp: rwx/bin/rm
[Root @ localhost pp] # su-pp
[Pp @ localhost ~] $ Rm-rf test/
[Pp @ localhost ~] $

15. package and exclude directory usage

Tar zcvf family.tar.gz./family/* -- exclude =./family/1/ss/attachments -- exclude =./family/1/ss/bbs/attachments

16. Upload folders in command line mode in linux

Ncftpput-R-u user-p 'passwd'-P 21 192.168.1.1/home/test // root/test (original directory)

4. view the top 15 programs that occupy the most memory

Ps-aux | awk '{print $4 "\ t" $11}' | grep-v MEM | sort-r | uniq-c | head-15

Ps (shift + M View memory usage, shift + p view cpu)