Avètisman
Bonjou tout moun! Non mwen se Sasha, epi mwen te teste backend (sèvis Linux ak API) pou plis pase sis ane. Lide pou atik la te vin jwenn mwen apre yon lòt demann nan men yon zanmi tèsteur pou di l 'sa li te kapab li sou kòmandman Linux anvan yon entèvyou. Tipikman, yon kandida pou yon pozisyon enjenyè QA oblije konnen kòmandman debaz yo (si, nan kou, yo enplike travay ak Linux), men ki jan ou fè konnen ki kòmandman yo vo lekti sou pandan y ap prepare pou yon entèvyou si ou gen ti kras. oswa pa gen eksperyans ak Linux?
Se poutèt sa, byenke sa a te deja ekri sou plizyè fwa, mwen toujou deside ekri yon lòt atik "Linux pou débutan" ak lis isit la kòmandman debaz ke ou bezwen konnen anvan nenpòt entèvyou nan yon depatman (oswa konpayi) ki sèvi ak Linux. Mwen te panse sou ki kòmandman ak sèvis piblik yo ak ak ki paramèt mwen itilize pi souvan, kolekte fidbak nan men kòlèg mwen yo, ak konpile li tout nan yon sèl atik. Atik la divize an 3 pati: premye, enfòmasyon kout sou Basics yo nan I / O nan tèminal Linux la, Lè sa a, yon BECA de kòmandman ki pi fondamantal yo, ak twazyèm pati a dekri kijan pou rezoud pwoblèm komen nan Linux.
Chak kòmand gen anpil opsyon, tout nan yo pa pral nan lis isit la. Ou ka toujou antre `man <kòmand>`oswa`<kòmand> --help` pou aprann plis sou ekip la.
Egzanp:
[user@testhost ~]$ mkdir --help Usage: mkdir [OPTION]... DIRECTORY... Create the DIRECTORY(ies), if they do not already exist. Mandatory arguments to long options are mandatory for short options too. -m, --mode=MODE set file mode (as in chmod), not a=rwx - umask -p, --parents no error if existing, make parent directories as needed -v, --verbose print a message for each created directory -Z set SELinux security context of each created directory to the default type --context[=CTX] like -Z, or if CTX is specified then set the SELinux or SMACK security context to CTX --help display this help and exit --version output version information and exit GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'mkdir invocation'
Si yon lòd pran twòp tan pou konplete, ou ka mete fen nan li lè w klike sou konsole a Ctrl + C (Yo voye yon siyal nan pwosesis la SIGINT).
Yon ti kras sou pwodiksyon lòd
Lè yon pwosesis kòmanse nan Linux, 3 kouran done estanda yo kreye pou pwosesis sa a: stdin, stdout и stderr. Yo nimewote 0, 1 ak 2 respektivman. Men kounye a nou enterese stdout epi, nan yon pi piti limit, stderr. Soti nan non yo li fasil devine sa stdout yo itilize pou pwodiksyon done, ak stderr — pou montre mesaj erè. Pa default lè w ap kouri yon lòd sou Linux stdout и stderr bay tout enfòmasyon yo nan konsole a, sepandan, si pwodiksyon lòd la gwo, li ka pratik pou redireksyon li nan yon dosye. Sa a ka fè, pou egzanp, tankou sa a:
[user@testhost ~]$ man signal > man_signal
Si nou soti sa ki nan dosye a man_signal, Lè sa a, nou pral wè ke li se ki idantik ak sa li ta si nou tou senpleman kouri lòd la `siyal moun`.
Redireksyon operasyon `>` par défaut stdout. Ou ka presize yon redireksyon stdout klèman: `1>`. Menm jan an tou, ou ka presize redireksyon stderr:`2>`. Ou ka konbine operasyon sa yo epi konsa separe pwodiksyon lòd nòmal ak pwodiksyon mesaj erè:
[user@testhost ~]$ man signal 1> man_signal 2> man_signal_error_log
Redireksyon ak stdout, Ak stderr nan yon sèl dosye jan sa a:
[user@testhost ~]$ man signal > man_signal 2>&1
Redireksyon operasyon `2> & 1` vle di redireksyon stderr nan menm kote a kòm dirije stdout.
Yon lòt zouti pratik pou travay ak I/O (oswa pito, li se yon zouti pratik pou kominikasyon ant pwosesis) se tiyo (Oswa transporteur). Pipelines yo souvan itilize pou kominike plizyè kòmandman: stdout kòmandman yo redireksyon sou stdin pwochen, ak sou sa nan chèn lan:
[user@testhost ~]$ ps aux | grep docker | tail -n 2
root 1045894 0.0 0.0 7512 3704 ? Sl 16:04 0:00 docker-containerd-shim -namespace moby -workdir /var/lib/docker/containerd/daemon/io.containerd.runtime.v1.linux/moby/2fbfddaf91c1bb7b9a0a6f788f3505dd7266f1139ad381d5b51ec1f47e1e7b28 -address /var/run/docker/containerd/docker-containerd.sock -containerd-binary /usr/bin/docker-containerd -runtime-root /var/run/docker/runtime-runc
531 1048313 0.0 0.0 110520 2084 pts/2 S+ 16:12 0:00 grep --color=auto docker
Kòmandman Linux debaz yo
pwd
Montre anyè aktyèl (k ap travay).
[user@testhost ~]$ pwd
/home/user
dat
Montre dat ak lè sistèm aktyèl la.
[user@testhost ~]$ date
Mon Dec 16 13:37:07 UTC 2019
[user@testhost ~]$ date +%s
1576503430
w
Kòmandman sa a montre ki moun ki konekte nan sistèm lan. Anplis de sa, uptime ak LA (chaj mwayèn) yo parèt tou sou ekran an.
[user@testhost ~]$ w
05:47:17 up 377 days, 17:57, 1 user, load average: 0,00, 0,01, 0,05
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
user pts/0 32.175.94.241 05:47 2.00s 0.01s 0.00s w
ls
Enprime sa ki nan yon anyè. Si ou pa pase chemen an, sa ki nan anyè aktyèl la pral parèt.
[user@testhost ~]$ pwd
/home/user
[user@testhost ~]$ ls
qqq
[user@testhost ~]$ ls /home/user
qqq
[user@testhost ~]$ ls /
bin boot cgroup dev etc home lib lib64 local lost+found media mnt opt proc root run sbin selinux srv swap sys tmp usr var
Pèsonèlman, mwen souvan itilize opsyon yo -l (fòma lis long - pwodiksyon nan yon kolòn ak plis enfòmasyon sou dosye), -t (Tout pa tan modifikasyon dosye/anyè) ak -r (klas ranvèse - an konbinezon ak -t dosye ki pi resan yo pral anba a):
[user@testhost ~]$ ls -ltr /
total 4194416
drwxr-xr-x 2 root root 4096 Jan 6 2012 srv
drwxr-xr-x 2 root root 4096 Jan 6 2012 selinux
drwxr-xr-x 2 root root 4096 Jan 6 2012 mnt
drwxr-xr-x 2 root root 4096 Jan 6 2012 media
drwx------ 2 root root 16384 Oct 1 2017 lost+found
drwxr-xr-x 2 root root 4096 Oct 1 2017 local
drwxr-xr-x 13 root root 4096 Oct 1 2017 usr
drwxr-xr-x 11 root root 4096 Apr 10 2018 cgroup
drwxr-xr-x 4 root root 4096 Apr 10 2018 run
-rw------- 1 root root 4294967296 Sep 10 2018 swap
dr-xr-xr-x 10 root root 4096 Dec 13 2018 lib
drwxr-xr-x 6 root root 4096 Mar 7 2019 opt
drwxr-xr-x 20 root root 4096 Mar 19 2019 var
dr-xr-xr-x 10 root root 12288 Apr 9 2019 lib64
dr-xr-xr-x 2 root root 4096 Apr 9 2019 bin
dr-xr-xr-x 4 root root 4096 Apr 9 2019 boot
dr-xr-xr-x 2 root root 12288 Apr 9 2019 sbin
dr-xr-xr-x 3229 root root 0 Jul 2 10:19 proc
drwxr-xr-x 34 root root 4096 Oct 28 13:27 home
drwxr-xr-x 93 root root 4096 Oct 30 16:00 etc
dr-xr-x--- 11 root root 4096 Nov 1 13:02 root
dr-xr-xr-x 13 root root 0 Nov 13 20:28 sys
drwxr-xr-x 16 root root 2740 Nov 26 08:55 dev
drwxrwxrwt 3 root root 4096 Nov 26 08:57 tmp
Gen 2 non anyè espesyal: "."Ak"..". Premye a vle di anyè aktyèl la, dezyèm lan vle di anyè paran an. Yo ka pratik pou itilize nan divès ekip, an patikilye ls:
[user@testhost home]$ pwd
/home
[user@testhost home]$ ls ..
bin boot cgroup dev etc home lib lib64 local lost+found media mnt opt proc root run sbin selinux srv swap sys tmp usr var
[user@testhost home]$ ls ../home/user/
qqq
Genyen tou yon opsyon itil pou montre dosye kache (kòmanse ak ".") - -a:
[user@testhost ~]$ ls -a
. .. 1 .bash_history .bash_logout .bash_profile .bashrc .lesshst man_signal man_signal_error_log .mongorc.js .ssh temp test .viminfo
Ou kapab tou itilize opsyon an -h - pwodiksyon nan fòma moun lizib (peye atansyon sou gwosè dosye):
[user@testhost ~]$ ls -ltrh
total 16K
-rwxrwx--x 1 user user 31 Nov 26 11:09 temp
-rw-rw-r-- 1 user user 6.0K Dec 3 16:02 1
drwxrwxr-x 2 user user 4.0K Dec 4 10:39 test
cd
Chanje anyè aktyèl la.
[user@testhost ~]$ pwd
/home/user
[user@testhost ~]$ cd /home/
[user@testhost home]$ pwd
/home
Si ou pa pase non anyè kòm yon agiman, yo pral itilize varyab anviwònman an $ LAKAY, sa vle di, anyè kay la. Li kapab tou pratik pou itilize `~` se yon karaktè espesyal siyifikasyon $ LAKAY:
[user@testhost etc]$ pwd
/etc
[user@testhost etc]$ cd ~/test/
[user@testhost test]$ pwd
/home/user/test
mkdir
Kreye yon anyè.
[user@testhost ~]$ mkdir test
[user@testhost ~]$ ls -ltr
total 38184
-rw-rw-r-- 1 user user 39091284 Nov 22 14:14 qqq
drwxrwxr-x 2 user user 4096 Nov 26 10:29 test
Pafwa ou bezwen kreye yon estrikti anyè espesifik: pou egzanp, yon anyè nan yon anyè ki pa egziste. Pou evite antre plizyè fwa nan yon ranje mkdir, ou ka itilize opsyon an -p — li pèmèt ou kreye tout anyè ki manke yo nan yerachi a. Epitou ak opsyon sa a mkdir pa pral retounen yon erè si anyè a egziste.
[user@testhost ~]$ ls
qqq test
[user@testhost ~]$ mkdir test2/subtest
mkdir: cannot create directory ‘test2/subtest’: No such file or directory
[user@testhost ~]$ mkdir -p test2/subtest
[user@testhost ~]$ ls
qqq test test2
[user@testhost ~]$ ls test2/
subtest
[user@testhost ~]$ mkdir test2/subtest
mkdir: cannot create directory ‘test2/subtest’: File exists
[user@testhost ~]$ mkdir -p test2/subtest
[user@testhost ~]$ ls test2/
subtest
rm
Efase yon fichye.
[user@testhost ~]$ ls
qqq test test2
[user@testhost ~]$ rm qqq
[user@testhost ~]$ ls
test test2
Opsyon -r pèmèt ou rekursiv efase anyè ak tout sa yo, opsyon -f pèmèt ou inyore erè lè w ap efase (pa egzanp, sou yon dosye ki pa egziste). Opsyon sa yo pèmèt, apeprè pale, yon efase garanti nan yerachi a tout antye nan dosye ak repèrtwar (si itilizatè a gen dwa fè sa), kidonk, yo ta dwe itilize ak prekosyon (yon egzanp blag klasik se "rm-rf /", nan sèten sikonstans, pral efase ou, si se pa tout sistèm nan, Lè sa a, yon anpil nan dosye enpòtan pou pèfòmans li).
[user@testhost ~]$ ls
test test2
[user@testhost ~]$ ls -ltr test2/
total 4
-rw-rw-r-- 1 user user 0 Nov 26 10:40 temp
drwxrwxr-x 2 user user 4096 Nov 26 10:40 temp_dir
[user@testhost ~]$ rm -rf test2
[user@testhost ~]$ ls
test
cp
Kopi yon dosye oswa yon anyè.
[user@testhost ~]$ ls
temp test
[user@testhost ~]$ cp temp temp_clone
[user@testhost ~]$ ls
temp temp_clone test
Kòmand sa a tou gen opsyon -r и -f, yo ka itilize pou asire ke yerachi anyè ak dosye yo kopye nan yon lòt kote.
mv
Deplase oswa chanje non yon fichye oswa anyè.
[user@testhost ~]$ ls -ltr
total 4
drwxrwxr-x 2 user user 4096 Nov 26 10:29 test
-rw-rw-r-- 1 user user 0 Nov 26 10:45 temp
-rw-rw-r-- 1 user user 0 Nov 26 10:46 temp_clone
[user@testhost ~]$ ls test
[user@testhost ~]$ mv test test_renamed
[user@testhost ~]$ mv temp_clone test_renamed/
[user@testhost ~]$ ls
temp test_renamed
[user@testhost ~]$ ls test_renamed/
temp_clone
chat
Enprime sa ki nan yon dosye (oswa dosye).
[user@testhost ~]$ cat temp
Content of a file.
Lalalala...
Li se tou vo peye atansyon sou kòmandman yo tèt (pwodiksyon n premye liy oswa octets nan dosye a) ak ke (plis sou li pita).
ke
Retire n dènye liy oswa octets nan dosye a.
[user@testhost ~]$ tail -1 temp
Lalalala...
Opsyon an trè itil -f — li pèmèt ou montre nouvo done nan yon dosye an tan reyèl.
mwens
Pafwa dosye tèks la twò gwo epi li pa konvenyan pou montre li ak lòd la chat. Lè sa a, ou ka louvri li lè l sèvi avèk lòd la mwens: fichye a pral pwodiksyon an pati; navigasyon nan pati sa yo, rechèch ak lòt fonksyonalite senp ki disponib.
[user@testhost ~]$ less temp
Li kapab tou pratik pou itilize mwens ak transporteur (tiyo):
[user@testhost ~]$ grep "ERROR" /tmp/some.log | less
ps
Lis pwosesis yo.
[user@testhost ~]$ ps
PID TTY TIME CMD
761020 pts/2 00:00:00 bash
809720 pts/2 00:00:00 ps
Mwen menm mwen anjeneral itilize opsyon BSD yo "aux"- montre tout pwosesis nan sistèm nan (piske ka gen anpil pwosesis, mwen parèt sèlman 5 premye nan yo lè l sèvi avèk tiyo a (tiyo) ak ekip tèt):
[user@testhost ~]$ ps aux | head -5
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.0 19692 2600 ? Ss Jul02 0:10 /sbin/init
root 2 0.0 0.0 0 0 ? S Jul02 0:03 [kthreadd]
root 4 0.0 0.0 0 0 ? I< Jul02 0:00 [kworker/0:0H]
root 6 0.0 0.0 0 0 ? I< Jul02 0:00 [mm_percpu_wq]
Anpil tou itilize opsyon BSD "axjf", ki pèmèt ou montre pye bwa pwosesis la (isit la mwen retire yon pati nan pwodiksyon an pou demonstrasyon):
[user@testhost ~]$ ps axjf
PPID PID PGID SID TTY TPGID STAT UID TIME COMMAND
0 2 0 0 ? -1 S 0 0:03 [kthreadd]
2 4 0 0 ? -1 I< 0 0:00 _ [kworker/0:0H]
2 6 0 0 ? -1 I< 0 0:00 _ [mm_percpu_wq]
2 7 0 0 ? -1 S 0 4:08 _ [ksoftirqd/0]
...
...
...
1 4293 4293 4293 tty6 4293 Ss+ 0 0:00 /sbin/mingetty /dev/tty6
1 532967 532964 532964 ? -1 Sl 495 0:00 /opt/td-agent/embedded/bin/ruby /usr/sbin/td-agent --log /var/log/td-agent/td-agent.log --use-v1-config --group td-agent --daemon /var/run/td-agent/td-agent.pid
532967 532970 532964 532964 ? -1 Sl 495 803:06 _ /opt/td-agent/embedded/bin/ruby /usr/sbin/td-agent --log /var/log/td-agent/td-agent.log --use-v1-config --group td-agent --daemon /var/run/td-agent/td-agent.pid
1 537162 533357 532322 ? -1 Sl 0 5067:43 /usr/bin/dockerd --default-ulimit nofile=262144:262144 --dns=172.17.0.1
537162 537177 537177 537177 ? -1 Ssl 0 4649:28 _ docker-containerd --config /var/run/docker/containerd/containerd.toml
537177 537579 537579 537177 ? -1 Sl 0 4:48 | _ docker-containerd-shim -namespace moby -workdir /var/lib/docker/containerd/daemon/io.containerd.runtime.v1.linux/moby/0ee89b20deb3cf08648cd92e1f3e3c661ccffef7a0971
537579 537642 537642 537642 ? -1 Ss 1000 32:11 | | _ /usr/bin/python /usr/bin/supervisord -c /etc/supervisord/api.conf
537642 539764 539764 537642 ? -1 S 1000 0:00 | | _ sh -c echo "READY"; while read -r line; do echo "$line"; supervisorctl shutdown; done
537642 539767 539767 537642 ? -1 S 1000 5:09 | | _ php-fpm: master process (/etc/php73/php-fpm.conf)
539767 783097 539767 537642 ? -1 S 1000 0:00 | | | _ php-fpm: pool test
539767 783131 539767 537642 ? -1 S 1000 0:00 | | | _ php-fpm: pool test
539767 783185 539767 537642 ? -1 S 1000 0:00 | | | _ php-fpm: pool test
...
...
...
Kòmandman sa a gen anpil opsyon diferan, kidonk si ou aktivman itilize li, mwen rekòmande ke ou li dokiman an. Pou pifò ka, li ase jis konnen "ps pou".
touye
Voye yon siyal nan yon pwosesis. Pa default siyal la voye TÈM sib, ki mete fen nan pwosesis la.
[user@testhost ~]$ ps ux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
531 1027147 0.0 0.0 119956 4260 ? S 14:51 0:00 sshd: user@pts/1
531 1027149 0.0 0.0 115408 3396 pts/1 Ss 14:51 0:00 -bash
531 1027170 0.0 0.0 119956 4136 ? R 14:51 0:00 sshd: user@pts/2
531 1027180 0.0 0.0 115408 3564 pts/2 Ss 14:51 0:00 -bash
531 1033727 0.0 0.0 107960 708 pts/1 S+ 15:17 0:00 sleep 300
531 1033752 0.0 0.0 117264 2604 pts/2 R+ 15:17 0:00 ps ux
[user@testhost ~]$ kill 1033727
[user@testhost ~]$ ps ux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
531 1027147 0.0 0.0 119956 4260 ? S 14:51 0:00 sshd: user@pts/1
531 1027149 0.0 0.0 115408 3396 pts/1 Ss+ 14:51 0:00 -bash
531 1027170 0.0 0.0 119956 4136 ? R 14:51 0:00 sshd: user@pts/2
531 1027180 0.0 0.0 115408 3564 pts/2 Ss 14:51 0:00 -bash
531 1033808 0.0 0.0 117268 2492 pts/2 R+ 15:17 0:00 ps ux
Depi yon pwosesis ka gen moun kap okipe siyal, touye pa toujou mennen nan rezilta a espere - fini imedya nan pwosesis la. Pou "touye" yon pwosesis pou asire w, ou bezwen voye yon siyal nan pwosesis la SIGKILL. Sepandan, sa ka mennen nan pèt done (pa egzanp, si pwosesis la bezwen pou konsève pou kèk enfòmasyon sou disk anvan yo mete fen), kidonk ou bezwen sèvi ak lòd sa a ak prekosyon. Nimewo siyal SIGKILL - 9, kidonk vèsyon an kout nan lòd la sanble sa a:
[user@testhost ~]$ ps ux | grep sleep
531 1034930 0.0 0.0 107960 636 pts/1 S+ 15:21 0:00 sleep 300
531 1034953 0.0 0.0 110516 2104 pts/2 S+ 15:21 0:00 grep --color=auto sleep
[user@testhost ~]$ kill -9 1034930
[user@testhost ~]$ ps ux | grep sleep
531 1035004 0.0 0.0 110516 2092 pts/2 S+ 15:22 0:00 grep --color=auto sleep
Anplis de sa yo mansyone TÈM sib и SIGKILL Gen anpil lòt siyal diferan; yon lis yo ka fasil jwenn sou entènèt la. Epi pa bliye ke siyal yo SIGKILL и NEXTSTOP pa ka entèsepte oswa inyore.
Ping
Voye yon pake ICMP bay lame a ECHO_REQUEST.
[user@testhost ~]$ ping google.com
PING google.com (172.217.15.78) 56(84) bytes of data.
64 bytes from iad23s63-in-f14.1e100.net (172.217.15.78): icmp_seq=1 ttl=47 time=1.85 ms
64 bytes from iad23s63-in-f14.1e100.net (172.217.15.78): icmp_seq=2 ttl=47 time=1.48 ms
64 bytes from iad23s63-in-f14.1e100.net (172.217.15.78): icmp_seq=3 ttl=47 time=1.45 ms
64 bytes from iad23s63-in-f14.1e100.net (172.217.15.78): icmp_seq=4 ttl=47 time=1.46 ms
64 bytes from iad23s63-in-f14.1e100.net (172.217.15.78): icmp_seq=5 ttl=47 time=1.45 ms
^C
--- google.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4006ms
rtt min/avg/max/mdev = 1.453/1.541/1.850/0.156 ms
Pa default Ping travay jiskaske li sispann manyèlman. Se poutèt sa, opsyon a ka itil -c - kantite pake apre voye Ping pral konplete poukont li. Yon lòt opsyon mwen pafwa itilize se -i, entèval ki genyen ant voye pakè yo.
[user@testhost ~]$ ping -c 3 -i 5 google.com
PING google.com (172.217.5.238) 56(84) bytes of data.
64 bytes from iad30s07-in-f238.1e100.net (172.217.5.238): icmp_seq=1 ttl=47 time=1.55 ms
64 bytes from iad30s07-in-f14.1e100.net (172.217.5.238): icmp_seq=2 ttl=47 time=1.17 ms
64 bytes from iad30s07-in-f14.1e100.net (172.217.5.238): icmp_seq=3 ttl=47 time=1.16 ms
--- google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 10006ms
rtt min/avg/max/mdev = 1.162/1.295/1.551/0.181 ms
sch
Kliyan OpenSSH SSH pèmèt ou konekte ak yon lame aleka.
MacBook-Pro-User:~ user$ ssh [email protected]
Last login: Tue Nov 26 11:27:39 2019 from another_host
[user@testhost ~]$ hostname
testhost
Gen anpil nuans nan lè l sèvi avèk SSH, ak kliyan sa a tou gen yon gwo kantite kapasite, kidonk si ou vle (oswa bezwen) ou ka li sou li. .
scp
Kopi fichye ant lame (pou itilizasyon sa a sch).
[user@testhost ~]$ pwd
/home/user
[user@testhost ~]$ ls
temp test_renamed
[user@testhost ~]$ exit
logout
Connection to 11.11.22.22 closed.
MacBook-Pro-Aleksandr:~ user$ scp [email protected]:/home/user/temp Downloads/
temp 100% 31 0.2KB/s 00:00
MacBook-Pro-Aleksandr:~ user$ cat Downloads/temp
Content of a file.
Lalalala...
rsync
Ou ka itilize tou pou senkronize anyè ant hôtes rsync (-a - mòd achiv, pèmèt ou kopye tout sa ki nan anyè a "jan yo ye", -v - pwodiksyon nan konsole enfòmasyon adisyonèl):
MacBook-Pro-User:~ user$ ls Downloads/user
ls: Downloads/user: No such file or directory
MacBook-Pro-User:~ user$ rsync -av user@testhost:/home/user Downloads
receiving file list ... done
user/
user/.bash_history
user/.bash_logout
user/.bash_profile
user/.bashrc
user/.lesshst
user/.mongorc.js
user/.viminfo
user/1
user/man_signal
user/man_signal_error_log
user/temp
user/.ssh/
user/.ssh/authorized_keys
user/test/
user/test/created_today
user/test/temp_clone
sent 346 bytes received 29210 bytes 11822.40 bytes/sec
total size is 28079 speedup is 0.95
MacBook-Pro-User:~ user$ ls -a Downloads/user
. .bash_history .bash_profile .lesshst .ssh 1 man_signal_error_log test
.. .bash_logout .bashrc .mongorc.js .viminfo man_signal temp
manke
Montre yon liy tèks.
[user@testhost ~]$ echo "Hello"
Hello
Opsyon vo konsidere isit la -n - pa ajoute liy lan ak yon kase liy nan fen a, epi -e — pèmèt entèpretasyon chape lè l sèvi avèk "".
[user@testhost ~]$ echo "tHellon"
tHellon
[user@testhost ~]$ echo -n "tHellon"
tHellon[user@testhost ~]$
[user@testhost ~]$ echo -ne "tHellon"
Hello
Ou kapab tou montre valè varyab yo lè l sèvi avèk lòd sa a. Pou egzanp, nan Linux kòd la sòti nan dènye kòmandman ranpli a ki estoke nan yon varyab espesyal $?, ak fason sa a ou ka chèche konnen egzakteman ki erè ki te fèt nan dènye aplikasyon an kouri:
[user@testhost ~]$ ls # ошибки не будет
1 man_signal man_signal_error_log temp test
[user@testhost ~]$ echo $? # получим 0 — ошибки не было
0
[user@testhost ~]$ ls qwerty # будет ошибка
ls: cannot access qwerty: No such file or directory
[user@testhost ~]$ echo $? # получим 2 — Misuse of shell builtins (according to Bash documentation)
2
[user@testhost ~]$ echo $? # последний echo отработал без ошибок, получим 0
0
telne
Kliyan pou pwotokòl TELNET. Yo itilize pou kominike ak yon lòt lame.
[user@testhost ~]$ telnet example.com 80
Trying 93.184.216.34...
Connected to example.com.
Escape character is '^]'.
GET / HTTP/1.1
Host: example.com
HTTP/1.1 200 OK
Cache-Control: max-age=604800
Content-Type: text/html; charset=UTF-8
Date: Tue, 26 Nov 2019 11:59:18 GMT
Etag: "3147526947+gzip+ident"
Expires: Tue, 03 Dec 2019 11:59:18 GMT
Last-Modified: Thu, 17 Oct 2019 07:18:26 GMT
Server: ECS (dcb/7F3B)
Vary: Accept-Encoding
X-Cache: HIT
Content-Length: 1256
... здесь было тело ответа, которое я вырезал руками ...
Si ou bezwen sèvi ak pwotokòl TLS (kite m fè w sonje ke SSL te demode depi lontan), lè sa a telne pa apwopriye pou rezon sa yo. Men kliyan an ap vini opansl:
Yon egzanp lè l sèvi avèk openssl ak pwodiksyon yon repons a yon demann GET
[user@testhost ~]$ openssl s_client -connect example.com:443
CONNECTED(00000003)
depth=2 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Global Root CA
verify return:1
depth=1 C = US, O = DigiCert Inc, CN = DigiCert SHA2 Secure Server CA
verify return:1
depth=0 C = US, ST = California, L = Los Angeles, O = Internet Corporation for Assigned Names and Numbers, OU = Technology, CN = www.example.org
verify return:1
---
Certificate chain
0 s:/C=US/ST=California/L=Los Angeles/O=Internet Corporation for Assigned Names and Numbers/OU=Technology/CN=www.example.org
i:/C=US/O=DigiCert Inc/CN=DigiCert SHA2 Secure Server CA
1 s:/C=US/O=DigiCert Inc/CN=DigiCert SHA2 Secure Server CA
i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert Global Root CA
2 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert Global Root CA
i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert Global Root CA
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=/C=US/ST=California/L=Los Angeles/O=Internet Corporation for Assigned Names and Numbers/OU=Technology/CN=www.example.org
issuer=/C=US/O=DigiCert Inc/CN=DigiCert SHA2 Secure Server CA
---
No client certificate CA names sent
Peer signing digest: SHA256
Server Temp Key: ECDH, P-256, 256 bits
---
SSL handshake has read 4643 bytes and written 415 bytes
---
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES128-GCM-SHA256
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
Protocol : TLSv1.2
Cipher : ECDHE-RSA-AES128-GCM-SHA256
Session-ID: 91950DC50FADB57BF026D2661E6CFAA1F522E5CA60D2310E106EE0E0FD6E70BD
Session-ID-ctx:
Master-Key: 704E9145253EEB4E9DC47E3DC6725D296D4A470EA296D54F71D65E74EAC09EB096EA1305CBEDD9E7020B8F72FD2B68A5
Key-Arg : None
Krb5 Principal: None
PSK identity: None
PSK identity hint: None
TLS session ticket lifetime hint: 7200 (seconds)
TLS session ticket:
0000 - 68 84 4e 77 be e3 f5 00-49 c5 44 40 53 4d b9 61 [email protected]
0010 - c9 fe df e4 05 51 d0 53-ae cf 89 4c b6 ef 6c 9e .....Q.S...L..l.
0020 - fe 12 9a f0 e8 e5 4e 87-42 89 ac af ca e5 4a 85 ......N.B.....J.
0030 - 38 08 26 e3 22 89 08 b5-62 c0 8b 7e b8 05 d3 54 8.&."...b..~...T
0040 - 8c 24 91 a7 b4 4f 79 ad-36 59 7c 69 2d e5 7f 62 .$...Oy.6Y|i-..b
0050 - f6 73 a3 8b 92 63 c1 e3-df 78 ba 8c 5a cc 82 50 .s...c...x..Z..P
0060 - 33 4e 13 4b 10 e4 97 31-cc b4 13 65 45 60 3e 13 3N.K...1...eE`>.
0070 - ac 9e b1 bb 4b 18 d9 16-ea ce f0 9b 5b 0c 8b bf ....K.......[...
0080 - fd 78 74 a0 1a ef c2 15-2a 0a 14 8d d1 3f 52 7a .xt.....*....?Rz
0090 - 12 6b c7 81 15 c4 c4 af-7e df c2 20 a8 dd 4b 93 .k......~.. ..K.
Start Time: 1574769867
Timeout : 300 (sec)
Verify return code: 0 (ok)
---
GET / HTTP/1.1
Host: example.com
HTTP/1.1 200 OK
Cache-Control: max-age=604800
Content-Type: text/html; charset=UTF-8
Date: Tue, 26 Nov 2019 12:04:38 GMT
Etag: "3147526947+ident"
Expires: Tue, 03 Dec 2019 12:04:38 GMT
Last-Modified: Thu, 17 Oct 2019 07:18:26 GMT
Server: ECS (dcb/7EC8)
Vary: Accept-Encoding
X-Cache: HIT
Content-Length: 1256
<!doctype html>
<html>
<head>
<title>Example Domain</title>
<meta charset="utf-8" />
<meta http-equiv="Content-type" content="text/html; charset=utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<style type="text/css">
body {
background-color: #f0f0f2;
margin: 0;
padding: 0;
font-family: -apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
}
div {
width: 600px;
margin: 5em auto;
padding: 2em;
background-color: #fdfdff;
border-radius: 0.5em;
box-shadow: 2px 3px 7px 2px rgba(0,0,0,0.02);
}
a:link, a:visited {
color: #38488f;
text-decoration: none;
}
@media (max-width: 700px) {
div {
margin: 0 auto;
width: auto;
}
}
</style>
</head>
<body>
<div>
<h1>Example Domain</h1>
<p>This domain is for use in illustrative examples in documents. You may use this
domain in literature without prior coordination or asking for permission.</p>
<p><a href="https://www.iana.org/domains/example">More information...</a></p>
</div>
</body>
</html>
Rezoud pwoblèm komen nan Linux
Chanje mèt fichye a
Ou ka chanje pwopriyetè a nan yon dosye oswa anyè lè l sèvi avèk lòd la chown:
[user@testhost ~]$ chown user:user temp
[user@testhost ~]$ ls -l temp
-rw-rw-r-- 1 user user 31 Nov 26 11:09 temp
Yo dwe bay paramèt kòmandman sa a nouvo pwopriyetè a ak gwoup (si ou vle), separe pa yon kolon. Epitou, lè w ap chanje mèt kay la nan yon anyè, opsyon a ka itil -R - Lè sa a, mèt pwopriyete yo pral chanje pou tout sa ki nan anyè a.
Chanje otorizasyon dosye yo
Pwoblèm sa a ka rezoud lè l sèvi avèk kòmandman an chmod. Kòm yon egzanp, mwen pral bay anviwònman pèmisyon an "pwopriyetè a gen dwa li, ekri ak egzekite, gwoup la gen dwa li ak ekri, tout lòt moun pa gen dwa anyen":
[user@testhost ~]$ ls -l temp
-rw-rw-r-- 1 user user 31 Nov 26 11:09 temp
[user@testhost ~]$ chmod 760 temp
[user@testhost ~]$ ls -l temp
-rwxrw---- 1 user user 31 Nov 26 11:09 temp
Premye 7 (sa a se 0b111 nan reprezantasyon ti jan an) nan paramèt la vle di "tout dwa pou mèt kay la", dezyèm 6 la (sa a se 0b110 nan reprezantasyon ti jan an) vle di "li ak ekri", ak 0 vle di pa gen anyen pou rès la. . Yon bitmask konsiste de twa bits: ti bit ki pi piti ("dwa") ki responsab pou ekzekisyon, ti ki pwochen ("megondè") se pou ekri, ak ti ki pi enpòtan ("gòch") se pou lekti.
Ou kapab tou mete pèmisyon lè l sèvi avèk karaktè espesyal (sentaks mnemonik). Pou egzanp, egzanp sa a an premye retire dwa ekzekisyon pou itilizatè aktyèl la ak Lè sa a, chanje yo tounen:
[user@testhost ~]$ ls -l temp
-rwxrw---- 1 user user 31 Nov 26 11:09 temp
[user@testhost ~]$ chmod -x temp
[user@testhost ~]$ ls -l temp
-rw-rw---- 1 user user 31 Nov 26 11:09 temp
[user@testhost ~]$ chmod +x temp
[user@testhost ~]$ ls -l temp
-rwxrwx--x 1 user user 31 Nov 26 11:09 temp
Kòmandman sa a gen anpil itilizasyon, kidonk mwen konseye w li plis sou li (espesyalman sou sentaks mnemonik la, pou egzanp, ).
Enprime sa ki nan yon dosye binè
Sa a ka fè lè l sèvi avèk sèvis piblik la hexdump. Anba a se egzanp itilizasyon li yo.
[user@testhost ~]$ cat temp
Content of a file.
Lalalala...
[user@testhost ~]$ hexdump -c temp
0000000 C o n t e n t o f a f i l
0000010 e . n L a l a l a l a . . . n
000001f
[user@testhost ~]$ hexdump -x temp
0000000 6f43 746e 6e65 2074 666f 6120 6620 6c69
0000010 2e65 4c0a 6c61 6c61 6c61 2e61 2e2e 000a
000001f
[user@testhost ~]$ hexdump -C temp
00000000 43 6f 6e 74 65 6e 74 20 6f 66 20 61 20 66 69 6c |Content of a fil|
00000010 65 2e 0a 4c 61 6c 61 6c 61 6c 61 2e 2e 2e 0a |e..Lalalala....|
0000001f
Sèvi ak sèvis piblik sa a, ou ka pwodiksyon done nan lòt fòma, men sa yo se opsyon ki pi souvan itil pou itilize li.
Chèche fichye yo
Ou ka jwenn yon fichye pa yon pati nan non li nan pye bwa anyè lè l sèvi avèk lòd la jwenn:
[user@testhost ~]$ find test_dir/ -name "*le*"
test_dir/file_1
test_dir/file_2
test_dir/subdir/file_3
Lòt opsyon rechèch ak filtè yo disponib tou. Pou egzanp, sa a se ki jan ou ka jwenn dosye nan yon katab tèskreye plis pase 5 jou de sa:
[user@testhost ~]$ ls -ltr test
total 0
-rw-rw-r-- 1 user user 0 Nov 26 10:46 temp_clone
-rw-rw-r-- 1 user user 0 Dec 4 10:39 created_today
[user@testhost ~]$ find test/ -type f -ctime +5
test/temp_clone
Chèche tèks nan dosye yo
Ekip la pral ede w fè fas ak travay sa a grep. Li gen anpil itilizasyon, youn nan pi senp yo bay isit la kòm yon egzanp.
[user@testhost ~]$ grep -nr "content" test_dir/
test_dir/file_1:1:test content for file_1
test_dir/file_2:1:test content for file_2
test_dir/subdir/file_3:1:test content for file_3
Youn nan fason popilè yo sèvi ak lòd la grep - itilize li nan yon tiyo (tiyo):
[user@testhost ~]$ sudo tail -f /var/log/test.log | grep "ERROR"
Opsyon -v pèmèt ou fè yon efè grep'ak ranvèse a - sèlman liy ki pa gen modèl la pase a grep.
Gade pakè enstale yo
Pa gen okenn lòd inivèsèl, paske tout bagay depann sou distribisyon an Linux ak manadjè a pake itilize. Gen plis chans youn nan kòmandman sa yo ap ede ou:
yum list installed
apt list --installed
zypper se —installed-only
pacman -Qqe
dpkg -l
rpm -qa
Gade konbyen espas pye bwa anyè a pran
Youn nan opsyon pou itilize kòmandman an du:
[user@testhost ~]$ du -h -d 1 test_dir/
8,0K test_dir/subdir
20K test_dir/
Ou ka chanje valè paramèt la -dpou jwenn plis enfòmasyon detaye sou pyebwa anyè a. Ou kapab tou itilize kòmandman an ansanm ak sòt:
[user@testhost ~]$ du -h -d 1 test_dir/ | sort -h
8,0K test_dir/subdir
16K test_dir/subdir_2
36K test_dir/
[user@testhost ~]$ du -h -d 1 test_dir/ | sort -h -r
36K test_dir/
16K test_dir/subdir_2
8,0K test_dir/subdir
Opsyon -h ekip la sòt pèmèt ou klase gwosè ekri nan fòma moun lizib (pa egzanp, 1K, 2G), opsyon -r pèmèt ou sòt done nan lòd ranvèse.
"Jwenn ak ranplase" nan yon dosye, nan dosye nan yon anyè
Operasyon sa a fèt lè l sèvi avèk sèvis piblik la SED (pa gen drapo g nan fen a, sèlman premye ensidan an nan "ansyen tèks" nan liy lan pral ranplase):
sed -i 's/old-text/new-text/g' input.txt
Ou ka sèvi ak li pou plizyè dosye nan yon fwa:
[user@testhost ~]$ cat test_dir/file_*
test content for file_1
test content for file_2
[user@testhost ~]$ sed -i 's/test/edited/g' test_dir/file_*
[user@testhost ~]$ cat test_dir/file_*
edited content for file_1
edited content for file_2
Trase yon kolòn nan pwodiksyon an
Li pral ede fè fas ak travay sa a woy. Egzanp sa a montre dezyèm kolòn pwodiksyon lòd `ps ux`:
[user@testhost ~]$ ps ux | awk '{print $2}'
PID
11023
25870
25871
25908
25909
An menm tan an, li dwe sonje bagay sa woy gen plis fonksyonalite pi rich, kidonk si ou bezwen travay ak tèks sou liy lòd la, ou ta dwe li plis sou lòd sa a.
Chèche adrès IP pa hostname
Youn nan kòmandman sa yo ap ede ak sa a:
[user@testhost ~]$ host ya.ru
ya.ru has address 87.250.250.242
ya.ru has IPv6 address 2a02:6b8::2:242
ya.ru mail is handled by 10 mx.yandex.ru.
[user@testhost ~]$ dig +short ya.ru
87.250.250.242
[user@testhost ~]$ nslookup ya.ru
Server: 8.8.8.8
Address: 8.8.8.8#53
Non-authoritative answer:
Name: ya.ru
Address: 87.250.250.242
Enfòmasyon sou rezo a
Ka itilize ifconfig:
[user@testhost ~]$ ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 47.89.93.67 netmask 255.255.224.0 broadcast 47.89.95.255
inet6 fd90::302:57ff:fe79:1 prefixlen 64 scopeid 0x20<link>
ether 04:01:57:79:00:01 txqueuelen 1000 (Ethernet)
RX packets 11912135 bytes 9307046034 (8.6 GiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 14696632 bytes 2809191835 (2.6 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 10 bytes 866 (866.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 10 bytes 866 (866.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Oswa petèt ip:
[user@testhost ~]$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 04:01:57:79:00:01 brd ff:ff:ff:ff:ff:ff
inet 47.89.93.67/19 brd 47.89.95.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fd90::302:57ff:fe79:1/64 scope link
valid_lft forever preferred_lft forever
3: ip_vti0: <NOARP> mtu 1500 qdisc noop state DOWN group default
link/ipip 0.0.0.0 brd 0.0.0.0
Anplis, si, pou egzanp, ou se sèlman enterese nan IPv4, Lè sa a, ou ka ajoute opsyon an -4:
[user@testhost ~]$ ip -4 a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
inet 47.89.93.67/19 brd 47.89.95.255 scope global eth0
valid_lft forever preferred_lft forever
Gade pò louvri
Pou fè sa, sèvi ak sèvis piblik la netstat. Pou egzanp, pou wè tout pò koute TCP ak UDP ak yon ekspozisyon PID nan pwosesis la koute sou pò a ak yon reprezantasyon nimerik nan pò a, ou bezwen sèvi ak li ak opsyon sa yo:
[user@testhost ~]$ netstat -lptnu
Enfòmasyon sistèm
Ou ka jwenn enfòmasyon sa yo lè l sèvi avèk kòmandman an unam.
[user@testhost ~]$ uname -a
Linux alexander 3.10.0-123.8.1.el7.x86_64 #1 SMP Mon Sep 22 19:06:58 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
Pou konprann fòma nan ki pwodiksyon an pwodui, ou ka fè referans a ede'pou kòmandman sa a:
[user@testhost ~]$ uname --help
Использование: uname [КЛЮЧ]…
Печатает определенные сведения о системе. Если КЛЮЧ не задан,
подразумевается -s.
-a, --all напечатать всю информацию, в следующем порядке,
кроме -p и -i, если они неизвестны:
-s, --kernel-name напечатать имя ядра
-n, --nodename напечатать имя машины в сети
-r, --release напечатать номер выпуска операционной системы
-v, --kernel-version напечатать версию ядра
-m, --machine напечатать тип оборудования машины
-p, --processor напечатать тип процессора или «неизвестно»
-i, --hardware-platform напечатать тип аппаратной платформы или «неизвестно»
-o, --operating-system напечатать имя операционной системы
--help показать эту справку и выйти
--version показать информацию о версии и выйти
Enfòmasyon memwa
Pou konprann konbyen RAM okipe oswa gratis, ou ka itilize kòmandman an gratis.
[user@testhost ~]$ free -h
total used free shared buff/cache available
Mem: 3,9G 555M 143M 56M 3,2G 3,0G
Swap: 0B 0B 0B
Enfòmasyon sou sistèm fichye (espas disk gratis)
Ekip df pèmèt ou wè ki kantite espas ki gratis ak okipe sou sistèm dosye monte.
[user@testhost ~]$ df -hT
Файловая система Тип Размер Использовано Дост Использовано% Cмонтировано в
/dev/vda1 ext4 79G 21G 55G 27% /
devtmpfs devtmpfs 2,0G 0 2,0G 0% /dev
tmpfs tmpfs 2,0G 0 2,0G 0% /dev/shm
tmpfs tmpfs 2,0G 57M 1,9G 3% /run
tmpfs tmpfs 2,0G 0 2,0G 0% /sys/fs/cgroup
tmpfs tmpfs 396M 0 396M 0% /run/user/1001
Opsyon -T presize ke yo ta dwe dedui kalite sistèm fichye a.
Enfòmasyon sou travay ak estatistik divès kalite sou sistèm nan
Pou fè sa, sèvi ak lòd la tèt. Li kapab montre plizyè enfòmasyon: pou egzanp, pwosesis tèt pa itilizasyon RAM oswa pwosesis tèt pa itilizasyon tan CPU. Li montre tou enfòmasyon sou memwa, CPU, uptime ak LA (chaj mwayèn).
[user@testhost ~]$ top | head -10
top - 17:19:13 up 154 days, 6:59, 3 users, load average: 0.21, 0.21, 0.27
Tasks: 2169 total, 2 running, 2080 sleeping, 0 stopped, 0 zombie
Cpu(s): 1.7%us, 0.7%sy, 0.0%ni, 97.5%id, 0.0%wa, 0.0%hi, 0.1%si, 0.0%st
Mem: 125889960k total, 82423048k used, 43466912k free, 16026020k buffers
Swap: 0k total, 0k used, 0k free, 31094516k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
25282 user 20 0 16988 3936 1964 R 7.3 0.0 0:00.04 top
4264 telegraf 20 0 2740m 240m 22m S 1.8 0.2 23409:39 telegraf
6718 root 20 0 35404 4768 3024 S 1.8 0.0 0:01.49 redis-server
Sèvis piblik sa a gen fonksyonalite rich, kidonk si ou bezwen sèvi ak li souvan, li pi bon pou li dokiman li yo.
Rezo trafik pil fatra
Pou entèsepte trafik rezo nan Linux, yo itilize yon sèvis piblik tcpdump. Pou jete trafik sou pò 12345, ou ka itilize lòd sa a:
[user@testhost ~]$ sudo tcpdump -i any -A port 12345
Opsyon -A di ke nou vle wè pwodiksyon an nan ASCII (konsa li bon pou pwotokòl tèks), -mwen nenpòt endike ke nou pa enterese nan koòdone rezo a, pò — ki pò trafik pou pil fatra. Olye de pò ou ka itilize lame, oswa yon konbinezon lame и pò (lame A ak pò X). Yon lòt opsyon itil ka -n — pa konvèti adrès yo nan hostnames nan pwodiksyon an.
E si trafik la se binè? Lè sa a, opsyon a ap ede nou -X - pwodiksyon done nan hex ak ASCII:
[user@testhost ~]$ sudo tcpdump -i any -X port 12345
Li ta dwe pran an kont ke nan tou de ka itilize pake IP yo pral pwodiksyon, kidonk nan kòmansman an nan chak nan yo pral gen binè IP ak TCP headers. Men yon egzanp pwodiksyon pou rechèch la "123" voye bay sèvè a ap koute sou pò 12345:
[user@testhost ~]$ sudo tcpdump -i any -X port 12345
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on any, link-type LINUX_SLL (Linux cooked), capture size 262144 bytes
14:27:13.224762 IP localhost.49794 > localhost.italk: Flags [P.], seq 2262177478:2262177483, ack 3317210845, win 342, options [nop,nop,TS val 3196604972 ecr 3196590131], length 5
0x0000: 4510 0039 dfb6 4000 4006 5cf6 7f00 0001 E..9..@.@......
0x0010: 7f00 0001 c282 3039 86d6 16c6 c5b8 9edd ......09........
0x0020: 8018 0156 fe2d 0000 0101 080a be88 522c ...V.-........R,
0x0030: be88 1833 3132 330d 0a00 0000 0000 0000 ...3123.........
0x0040: 0000 0000 0000 0000 00 .........
Olye pou yo pwodiksyon an
Natirèlman, gen anpil bagay ki pi enteresan nan Linux ke ou ka li sou Habré, StackOverflow ak lòt sit (mwen pral ba ou yon egzanp , ki se tou ). Administratè sistèm yo ak DevOps sèvi ak anpil lòt kòmandman ak sèvis piblik pou konfigirasyon serveurs, men menm tèsteur yo ka pa gen ase nan kòmandman ki nan lis la. Ou ka bezwen tcheke kòrèkteman kèk timeout difisil ant kliyan an ak sèvè a, oswa operasyon an nan sèvè a lè pa gen okenn espas disk gratis. Mwen pa menm pale de, pou egzanp, Docker, ki se kounye a aktivman itilize pa anpil konpayi. Èske li ta enteresan, nan kad kontinyasyon atik referans sa a, pou w gade plizyè egzanp lè w sèvi ak divès kalite sèvis piblik konsole Linux nan pwosesis tès sèvis yo? Epitou pataje pi gwo ekip ou yo nan kòmantè yo :)
Sous: www.habr.com