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Halo kabeh! Jenengku Sasha, lan aku wis nyoba backend (layanan Linux lan API) luwih saka enem taun. Gagasan kanggo artikel kasebut teka sawise panjaluk liyane saka kanca penguji kanggo ngandhani apa sing bisa diwaca babagan perintah Linux sadurunge wawancara. Biasane, calon kanggo posisi insinyur QA kudu ngerti perintah dhasar (yen mesthine melu nggarap Linux), nanging kepiye sampeyan ngerti prentah apa sing kudu diwaca nalika nyiapake wawancara yen sampeyan duwe sethithik. utawa ora duwe pengalaman karo Linux?
Mulane, sanajan iki wis ditulis kaping pirang-pirang, aku isih mutusake kanggo nulis artikel liyane "Linux kanggo pamula" lan dhaptar ing kene prentah dhasar sing kudu sampeyan ngerti sadurunge wawancara ing departemen (utawa perusahaan) sing nggunakake Linux. Aku mikir babagan prentah lan utilitas lan paramèter sing paling kerep digunakake, ngumpulake umpan balik saka kanca-kancaku, lan nglumpukake kabeh dadi siji artikel. Artikel kasebut dipérang dadi 3 bagean: pisanan, informasi ringkes babagan dasar-dasar I/O ing terminal Linux, banjur ringkesan perintah paling dhasar, lan bagean katelu nerangake carane ngatasi masalah umum ing Linux.
Saben printah duwe akeh pilihan, kabeh mau ora bakal kadhaptar ing kene. Sampeyan bisa tansah mlebu 'wong <prentah>`utawa`<prentah> --pitulung` kanggo sinau luwih akeh babagan tim.
Conto:
[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'
Yen prentah njupuk dawa banget kanggo ngrampungake, sampeyan bisa mungkasi kanthi ngeklik ing console Ctrl + C (sinyal dikirim menyang proses SIGN).
A sethitik babagan output printah
Nalika proses diwiwiti ing Linux, 3 aliran data standar digawe kanggo proses kasebut: stdin, stdout и stderr. Padha nomer 0, 1 lan 2 mungguh. Nanging saiki kita kasengsem stdout lan, nganti luwih sithik, stderr. Saka jeneng iku gampang kanggo guess sing stdout digunakake kanggo output data, lan stderr - kanggo nampilake pesen kesalahan. Kanthi gawan nalika mbukak printah ing Linux stdout и stderr output kabeh informasi kanggo console, Nanging, yen output printah gedhe, iku uga trep kanggo pangalihan menyang file. Iki bisa ditindakake, contone, kaya iki:
[user@testhost ~]$ man signal > man_signal
Yen kita output isi file wong_sinyal, banjur kita bakal weruh manawa padha karo apa sing bakal ditindakake yen kita mung nglakokake printah `sinyal wong`.
Operasi pangalihan `>` standar kanggo stdout. Sampeyan bisa nemtokake pangalihan stdout kanthi tegas: `1>`. Kajaba iku, sampeyan bisa nemtokake pangalihan stderr:`2>`. Sampeyan bisa nggabungake operasi kasebut lan kanthi mangkono misahake output printah normal lan output pesen kesalahan:
[user@testhost ~]$ man signal 1> man_signal 2> man_signal_error_log
Pangalihan lan stdoutlan stderr dadi siji file kaya ing ngisor iki:
[user@testhost ~]$ man signal > man_signal 2>&1
Operasi pangalihan `2> & 1` tegese pangalihan stderr menyang panggonan sing padha kaya sing diarahake stdout.
Alat trep liyane kanggo nggarap I / O (utawa luwih, iku alat trep kanggo komunikasi interprocess) punika Pipa (utawa conveyor). Pipelines asring digunakake kanggo komunikasi sawetara printah: stdout printah sing redirected menyang stdin sabanjure, lan sabanjure ing ranté:
[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
Prentah Linux dhasar
pwd
Tampilake direktori saiki (kerja).
[user@testhost ~]$ pwd
/home/user
tanggal
Tampilake tanggal lan wektu sistem saiki.
[user@testhost ~]$ date
Mon Dec 16 13:37:07 UTC 2019
[user@testhost ~]$ date +%s
1576503430
w
Printah iki nuduhake sapa sing mlebu ing sistem. Kajaba iku, uptime lan LA (load average) uga ditampilake ing layar.
[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
Print isi direktori. Yen sampeyan ora ngliwati dalan kasebut, isi direktori saiki bakal ditampilake.
[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
Secara pribadi, aku kerep nggunakake opsi kasebut -l (format dhaptar dawa - output menyang kolom kanthi informasi tambahan babagan file), -t (ngurutake miturut file / wektu modifikasi direktori) lan -r (ngurutake mbalikke - ing kombinasi karo -t file paling anyar bakal ana ing ngisor):
[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
Ana 2 jeneng direktori khusus: "."Lan"..". Sing pisanan tegese direktori saiki, sing kapindho tegese direktori induk. Bisa uga trep kanggo digunakake ing macem-macem tim, utamane 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
Ana uga pilihan sing migunani kanggo nampilake file sing didhelikake (wiwit ".")- -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
Sampeyan uga bisa nggunakake pilihan -h - output ing format sing bisa diwaca manungsa (nggatekake ukuran file):
[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
Ngganti direktori saiki.
[user@testhost ~]$ pwd
/home/user
[user@testhost ~]$ cd /home/
[user@testhost home]$ pwd
/home
Yen sampeyan ora ngliwati jeneng direktori minangka argumen, variabel lingkungan bakal digunakake $ RUMAH, yaiku, direktori ngarep. Bisa uga trep kanggo nggunakake `~` iku makna karakter khusus $ RUMAH:
[user@testhost etc]$ pwd
/etc
[user@testhost etc]$ cd ~/test/
[user@testhost test]$ pwd
/home/user/test
mkdir
Nggawe direktori.
[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
Kadhangkala sampeyan kudu nggawe struktur direktori tartamtu: contone, direktori ing direktori sing ora ana. Supaya ora mlebu kaping pirang-pirang saurutan mkdir, sampeyan bisa nggunakake pilihan -p - ngidini sampeyan nggawe kabeh direktori sing ilang ing hirarki. Uga karo pilihan iki mkdir ora bakal ngasilake kesalahan yen direktori ana.
[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
Mbusak file.
[user@testhost ~]$ ls
qqq test test2
[user@testhost ~]$ rm qqq
[user@testhost ~]$ ls
test test2
Pilihan -r ngijini sampeyan kanggo recursively mbusak direktori karo kabeh isi sing, pilihan -f ngidini sampeyan nglirwakake kesalahan nalika mbusak (contone, babagan file sing ora ana). Opsi kasebut ngidini, kira-kira, mbusak kabeh hierarki file lan direktori sing dijamin (yen pangguna duwe hak kanggo nindakake), mula, kudu digunakake kanthi ati-ati (conto lelucon klasik yaiku "rm-rf /", ing kahanan tartamtu, bakal mbusak sampeyan, yen ora kabeh sistem, banjur akeh file penting kanggo kinerja).
[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
Nyalin file utawa direktori.
[user@testhost ~]$ ls
temp test
[user@testhost ~]$ cp temp temp_clone
[user@testhost ~]$ ls
temp temp_clone test
Printah iki uga duwe opsi -r и -f, bisa digunakake kanggo mesthekake yen hierarki direktori lan folder disalin menyang lokasi liya.
mv
Pindhah utawa ganti jeneng file utawa direktori.
[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
kucing
Nyetak isi file (utawa file).
[user@testhost ~]$ cat temp
Content of a file.
Lalalala...
Iku uga worth mbayar manungsa waé kanggo printah sirah (keluaran n baris pisanan utawa bita saka file) lan buntut (luwih akeh babagan dheweke mengko).
buntut
Mundur n baris pungkasan utawa bita saka berkas.
[user@testhost ~]$ tail -1 temp
Lalalala...
Pilihan banget migunani -f - ngidini sampeyan nampilake data anyar ing file ing wektu nyata.
kurang
Kadhangkala file teks gedhe banget lan ora trep kanggo nampilake kanthi printah kucing. Banjur sampeyan bisa mbukak kanthi nggunakake printah kurang: file bakal metu ing bagean; navigasi liwat bagean kasebut, telusuran lan fungsi prasaja liyane kasedhiya.
[user@testhost ~]$ less temp
Bisa uga trep kanggo nggunakake kurang karo conveyor (Pipa):
[user@testhost ~]$ grep "ERROR" /tmp/some.log | less
ps
List pangolahan.
[user@testhost ~]$ ps
PID TTY TIME CMD
761020 pts/2 00:00:00 bash
809720 pts/2 00:00:00 ps
Aku dhewe biasane nggunakake opsi BSD "ing"- nampilake kabeh proses ing sistem (amarga ana akeh proses, aku mung nampilake 5 pisanan kanthi nggunakake pipa (Pipa) lan tim sirah):
[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]
Akeh uga nggunakake opsi BSD "axjf", sing ngidini sampeyan nampilake wit proses (kene aku mbusak bagean saka output kanggo demonstrasi):
[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 "$line"; supervisorctl shutdown; done
537642 539767 539767 537642 ? -1 S 1000 5:09 | | _ php-fpm: master process (/etc/php73/php-fpm.conf)
539767 783097 539767 537642 ? -1 S 1000 0:00 | | | _ php-fpm: pool test
539767 783131 539767 537642 ? -1 S 1000 0:00 | | | _ php-fpm: pool test
539767 783185 539767 537642 ? -1 S 1000 0:00 | | | _ php-fpm: pool test
...
...
...
Printah iki duwe macem-macem opsi, dadi yen sampeyan nggunakake kanthi aktif, aku nyaranake sampeyan maca dokumentasi. Umume kasus, cukup mung ngerti "ps awis".
matèni
Kirim sinyal menyang proses. Kanthi gawan sinyal dikirim TANDA, sing mungkasi proses kasebut.
[user@testhost ~]$ 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
Amarga proses bisa duwe panangan sinyal, matèni ora tansah mimpin kanggo asil samesthine - completion langsung saka proses. Kanggo "mateni" proses manawa, sampeyan kudu ngirim sinyal menyang proses kasebut SIGKILL. Nanging, iki bisa nyebabake mundhut data (contone, yen proses kasebut kudu nyimpen sawetara informasi menyang disk sadurunge mungkasi), dadi sampeyan kudu nggunakake printah iki kanthi ati-ati. Nomer sinyal SIGKILL - 9, supaya versi cendhak printah katon kaya iki:
[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
Saliyane sing kasebut TANDA и SIGKILL Ana akeh sinyal sing beda-beda; dhaptar kasebut bisa gampang ditemokake ing Internet. Lan aja lali yen sinyal kasebut SIGKILL и NEXTSTOP ora bisa dicegat utawa digatèkaké.
ping
Kirimi paket ICMP menyang host 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
standar ping dianggo nganti rampung kanthi manual. Mulane opsi kasebut bisa uga migunani -c - jumlah paket sawise dikirim ping bakal rampung dhewe. Pilihan liyane sing kadhangkala aku gunakake yaiku -i, interval antarane ngirim paket.
[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
SSH
Klien OpenSSH SSH ngidini sampeyan nyambung menyang host remot.
MacBook-Pro-User:~ user$ ssh [email protected]
Last login: Tue Nov 26 11:27:39 2019 from another_host
[user@testhost ~]$ hostname
testhost
Ana akeh nuansa ing nggunakake SSH, lan klien iki uga duwe nomer akeh kapabilitas, supaya yen sampeyan pengin (utawa perlu) sampeyan bisa maca babagan .
scp
Nyalin file antarane host (kanggo nggunakake iki SSH).
[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
Sampeyan uga bisa digunakake kanggo nyinkronake direktori ing antarane host rsync (-a - mode arsip, ngidini sampeyan nyalin kabeh isi direktori "kaya", -v - output menyang console informasi tambahan):
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
kumandhang
Tampilake baris teks.
[user@testhost ~]$ echo "Hello"
Hello
Pilihan worth considering kene -n - ora nambah baris karo break baris ing mburi, lan -e - ngaktifake interpretasi escaping nggunakake "".
[user@testhost ~]$ echo "tHellon"
tHellon
[user@testhost ~]$ echo -n "tHellon"
tHellon[user@testhost ~]$
[user@testhost ~]$ echo -ne "tHellon"
Hello
Sampeyan uga bisa nampilake nilai variabel nggunakake printah iki. Contone, ing Linux kode metu saka printah rampung pungkasan disimpen ing variabel khusus $?, lan kanthi cara iki sampeyan bisa ngerteni persis apa kesalahan sing kedadeyan ing aplikasi pungkasan sing mlaku:
[user@testhost ~]$ 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 $? # последний echo отработал без ошибок, получим 0
0
Telnet
Klien kanggo protokol TELNET. Digunakake kanggo komunikasi karo host liyane.
[user@testhost ~]$ 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 ...
Yen sampeyan kudu nggunakake protokol TLS (ayo kula ngelingake sampeyan yen SSL wis suwe ora ana), banjur Telnet ora cocog kanggo tujuan kasebut. Nanging klien bakal teka openssl:
Conto nggunakake openssl kanthi ngasilake respon kanggo panjaluk 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 .$...Oy.6Y|i-..b
0050 - f6 73 a3 8b 92 63 c1 e3-df 78 ba 8c 5a cc 82 50 .s...c...x..Z..P
0060 - 33 4e 13 4b 10 e4 97 31-cc b4 13 65 45 60 3e 13 3N.K...1...eE`>.
0070 - ac 9e b1 bb 4b 18 d9 16-ea ce f0 9b 5b 0c 8b bf ....K.......[...
0080 - fd 78 74 a0 1a ef c2 15-2a 0a 14 8d d1 3f 52 7a .xt.....*....?Rz
0090 - 12 6b c7 81 15 c4 c4 af-7e df c2 20 a8 dd 4b 93 .k......~.. ..K.
Start Time: 1574769867
Timeout : 300 (sec)
Verify return code: 0 (ok)
---
GET / HTTP/1.1
Host: example.com
HTTP/1.1 200 OK
Cache-Control: max-age=604800
Content-Type: text/html; charset=UTF-8
Date: Tue, 26 Nov 2019 12:04:38 GMT
Etag: "3147526947+ident"
Expires: Tue, 03 Dec 2019 12:04:38 GMT
Last-Modified: Thu, 17 Oct 2019 07:18:26 GMT
Server: ECS (dcb/7EC8)
Vary: Accept-Encoding
X-Cache: HIT
Content-Length: 1256
<!doctype html>
<html>
<head>
<title>Example Domain</title>
<meta charset="utf-8" />
<meta http-equiv="Content-type" content="text/html; charset=utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<style type="text/css">
body {
background-color: #f0f0f2;
margin: 0;
padding: 0;
font-family: -apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
}
div {
width: 600px;
margin: 5em auto;
padding: 2em;
background-color: #fdfdff;
border-radius: 0.5em;
box-shadow: 2px 3px 7px 2px rgba(0,0,0,0.02);
}
a:link, a:visited {
color: #38488f;
text-decoration: none;
}
@media (max-width: 700px) {
div {
margin: 0 auto;
width: auto;
}
}
</style>
</head>
<body>
<div>
<h1>Example Domain</h1>
<p>This domain is for use in illustrative examples in documents. You may use this
domain in literature without prior coordination or asking for permission.</p>
<p><a href="https://www.iana.org/domains/example">More information...</a></p>
</div>
</body>
</html>
Ngatasi masalah umum ing Linux
Ngganti pemilik file
Sampeyan bisa ngganti pemilik file utawa direktori nggunakake printah chown:
[user@testhost ~]$ chown user:user temp
[user@testhost ~]$ ls -l temp
-rw-rw-r-- 1 user user 31 Nov 26 11:09 temp
Parameter kanggo printah iki kudu diwenehi pemilik anyar lan grup (opsional), dipisahake dening titik loro. Uga, nalika ngganti pemilik direktori, opsi kasebut bisa migunani -R - banjur pamilik bakal ngganti kabeh isi direktori.
Ngganti ijin file
Masalah iki bisa ditanggulangi nggunakake printah Chmod. Minangka conto, aku bakal menehi setelan ijin "pemilik diijini maca, nulis lan nglakokake, grup diijini maca lan nulis, kabeh wong ora diijini":
[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
7 pisanan (iki 0b111 ing perwakilan bit) ing parameter tegese "kabeh hak kanggo pemilik", 6 kaloro (iki 0b110 ing perwakilan bit) tegese "maca lan nulis", lan 0 tegese apa-apa kanggo liyane . Bitmask kasusun saka telung bit: bit paling penting ("tengen") tanggung jawab kanggo eksekusi, bit sabanjure ("tengah") kanggo nulis, lan bit sing paling penting ("kiwa") kanggo maca.
Sampeyan uga bisa nyetel ijin nggunakake karakter khusus (sintaksis mnemonik). Contone, conto ing ngisor iki pisanan mbusak hak eksekusi kanggo pangguna saiki banjur ngganti maneh:
[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
Prentah iki akeh gunane, mula aku menehi saran supaya maca luwih lengkap babagan iki (utamane babagan sintaksis mnemonik, contone, ).
Nyetak isi file binar
Iki bisa ditindakake kanthi nggunakake sarana hexdump. Ing ngisor iki conto panggunaane.
[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
Nggunakake sarana iki, sampeyan bisa output data ing format liyane, nanging iki pilihan sing paling kerep migunani kanggo nggunakake.
Nggoleki file
Sampeyan bisa nemokake file kanthi bagean saka jenenge ing wit direktori nggunakake perintah kasebut golek:
[user@testhost ~]$ find test_dir/ -name "*le*"
test_dir/file_1
test_dir/file_2
test_dir/subdir/file_3
Opsi telusuran lan saringan liyane uga kasedhiya. Contone, iki carane sampeyan bisa nemokake file ing folder testdigawe luwih saka 5 dina kepungkur:
[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
Telusuri teks ing file
Tim bakal mbantu sampeyan ngrampungake tugas iki grep. Wis akeh kegunaan, sing paling gampang diwenehi ing kene minangka conto.
[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
Salah siji cara populer kanggo nggunakake printah grep - nggunakake ing pipa (Pipa):
[user@testhost ~]$ sudo tail -f /var/log/test.log | grep "ERROR"
Pilihan -v ngidini sampeyan nggawe efek grep'lan mbalikke - mung garis sing ora ngemot pola liwati grep.
Deleng paket sing diinstal
Ora ana prentah universal, amarga kabeh gumantung saka distribusi Linux lan manajer paket sing digunakake. Paling kamungkinan salah siji saka printah ing ngisor iki bakal mbantu:
yum list installed
apt list --installed
zypper se —installed-only
pacman -Qqe
dpkg -l
rpm -qa
Deleng sepira papan sing ditindakake wit direktori
Salah siji opsi kanggo nggunakake printah du:
[user@testhost ~]$ du -h -d 1 test_dir/
8,0K test_dir/subdir
20K test_dir/
Sampeyan bisa ngganti nilai parameter -dkanggo entuk informasi sing luwih rinci babagan wit direktori. Sampeyan uga bisa nggunakake printah ing kombinasi karo Urut:
[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
Pilihan -h tim Urut ngidini sampeyan ngurutake ukuran sing ditulis ing format sing bisa diwaca manungsa (contone, 1K, 2G), pilihan -r ngijini sampeyan kanggo ngurutake data ing urutan mbalikke.
"Golek lan ganti" ing file, ing file ing direktori
Operasi iki ditindakake kanthi nggunakake sarana sed (ora ana gendera g ing pungkasan, mung kedadeyan pisanan "teks lawas" ing baris sing bakal diganti):
sed -i 's/old-text/new-text/g' input.txt
Sampeyan bisa nggunakake kanggo sawetara file bebarengan:
[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
Tarik kolom saka output
Iku bakal bantuan kanggo ngrampungake karo tugas iki wah. Conto iki nampilake kolom kapindho output printah `ps ux`:
[user@testhost ~]$ ps ux | awk '{print $2}'
PID
11023
25870
25871
25908
25909
Ing wektu sing padha, kudu dieling-eling wah wis fungsi akeh sugih, supaya yen sampeyan kudu bisa karo teks ing baris printah, sampeyan kudu maca liyane babagan printah iki.
Temokake alamat IP kanthi jeneng host
Salah sawijining prentah ing ngisor iki bakal mbantu:
[user@testhost ~]$ 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
Informasi Jaringan
Bisa digunakake 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
Utawa mbok menawa 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
Menapa malih, yen, contone, sampeyan mung kasengsem ing IPv4, sampeyan bisa nambah pilihan -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
Ndeleng port mbukak
Kanggo nindakake iki, gunakake sarana netstat. Contone, kanggo ndeleng kabeh port ngrungokake TCP lan UDP kanthi tampilan PID proses ngrungokake ing port lan perwakilan numerik saka port, sampeyan kudu nggunakake opsi ing ngisor iki:
[user@testhost ~]$ netstat -lptnu
Informasi sistem
Sampeyan bisa njaluk informasi iki nggunakake printah uname.
[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
Kanggo mangerteni format kang output diprodhuksi, sampeyan bisa waca bantuan'kanggo prentah iki:
[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
Informasi memori
Kanggo ngerti carane akeh RAM dikuwasani utawa free, sampeyan bisa nggunakake printah free.
[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
Informasi babagan sistem file (ruang disk kosong)
tim df ngidini sampeyan ndeleng sepira papan sing gratis lan dikuwasani ing sistem file sing dipasang.
[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
Pilihan -T nemtokake manawa jinis sistem file kudu disimpulake.
Informasi babagan tugas lan macem-macem statistik ing sistem
Kanggo nindakake iki, gunakake perintah kasebut ndhuwur. Bisa nampilake macem-macem informasi: contone, pangolahan ndhuwur kanthi panggunaan RAM utawa proses ndhuwur kanthi panggunaan wektu CPU. Uga nampilake informasi babagan memori, CPU, uptime lan LA (rata-rata mbukak).
[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
Utilitas iki nduweni fungsi sing sugih, dadi yen sampeyan kudu kerep nggunakake, luwih becik maca dokumentasine.
Mbusak lalu lintas jaringan
Kanggo nyegat lalu lintas jaringan ing Linux, sarana digunakake tcpdump. Kanggo mbucal lalu lintas ing port 12345, sampeyan bisa nggunakake printah ing ngisor iki:
[user@testhost ~]$ sudo tcpdump -i any -A port 12345
Pilihan -A ujar manawa kita pengin ndeleng output ing ASCII (dadi apik kanggo protokol teks), -aku wae nuduhake yen kita ora kasengsem ing antarmuka jaringan, port - lalu lintas port kanggo mbucal. Tinimbang port bisa digunakake inang, utawa kombinasi inang и port (host A lan port X). Pilihan liyane sing migunani bisa uga -n - aja ngowahi alamat dadi hostname ing output.
Apa yen lalu lintas kasebut binar? Banjur pilihan bakal mbantu kita -X - data output ing hex lan ASCII:
[user@testhost ~]$ sudo tcpdump -i any -X port 12345
Sampeyan kudu eling yen ing kasus panggunaan, paket IP bakal dadi output, saengga ing wiwitan saben bakal ana header IP lan TCP binar. Iki minangka conto output kanggo pitakon "123" dikirim menyang server ngrungokake ing port 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 .........
Tinimbang output
Mesthine, ana akeh perkara sing luwih menarik ing Linux sing bisa diwaca ing Habré, StackOverflow lan situs liyane (Aku bakal menehi conto , kang uga ). Administrator sistem lan DevOps nggunakake akeh printah lan utilitas liyane kanggo ngatur server, nanging malah panguji bisa uga ora duwe cukup printah sing kadhaptar. Sampeyan bisa uga kudu mriksa kabeneran sawetara wektu entek angel antarane klien lan server, utawa operasi server nalika ora ana ruang disk gratis. Aku malah ora ngomong bab, contone, Docker, kang saiki aktif digunakake dening akeh perusahaan. Apa menarik, minangka bagean saka tutugan artikel referensi iki, ndeleng sawetara conto nggunakake macem-macem utilitas konsol Linux ing proses layanan tes? Uga nuduhake tim paling apik ing komentar :)
Source: www.habr.com