Kọ ẹkọ Bii o ṣe le Ṣẹda ati Ṣayẹwo Awọn faili pẹlu MD5 Checksum ni Lainos

Checksum jẹ nọmba kan ti o ṣiṣẹ bi apao awọn nọmba to tọ ninu data, eyiti o le ṣee lo nigbamii lati wa awọn aṣiṣe ninu data lakoko ipamọ tabi gbigbe. Awọn akopọ MD5 (Ifiranṣẹ Digest 5) le ṣee lo bi ibi ayẹwo lati ṣayẹwo awọn faili tabi awọn okun inu eto faili Linux kan.

Awọn akopọ MD5 jẹ awọn okun ohun kikọ 128-bit (awọn nọmba ati awọn lẹta) ti o jẹ abajade lati ṣiṣẹ algorithm MD5 lodi si faili kan pato. Algorithm MD5 jẹ iṣẹ elile ti o gbajumọ ti o ṣe agbejade ijẹrisi ifiranṣẹ 128-bit ti a tọka si bi iye elile, ati pe nigbati o ba ṣẹda ọkan fun faili kan pato, ko yipada ni deede lori ẹrọ eyikeyi laibikita nọmba awọn akoko ti o ti ipilẹṣẹ.

O jẹ deede nira pupọ lati wa awọn faili ọtọtọ meji ti o ṣe abajade awọn okun kanna. Nitorinaa, o le lo md5sum lati ṣayẹwo iyege data oni nọmba nipa ṣiṣe ipinnu pe faili kan tabi ISO ti o gba wọle jẹ ẹda bit-fun-bit ti faili latọna jijin tabi ISO.

Ni Lainos, eto md5sum ṣe iṣiro ati ṣayẹwo awọn iye hash MD5 ti faili kan. O jẹ ipin ti package GNU Core Utilities, nitorinaa o ti wa ni iṣaaju sori pupọ julọ, ti kii ba ṣe gbogbo awọn kaakiri Linux.

Wo awọn akoonu ti /ati be be lo/ẹgbẹ ti a fipamọ bi awọn ẹgbẹ.cvs ni isalẹ.

root:x:0:
daemon:x:1:
bin:x:2:
sys:x:3:
adm:x:4:syslog,aaronkilik
tty:x:5:
disk:x:6:
lp:x:7:
mail:x:8:
news:x:9:
uucp:x:10:
man:x:12:
proxy:x:13:
kmem:x:15:
dialout:x:20:
fax:x:21:
voice:x:22:
cdrom:x:24:aaronkilik
floppy:x:25:
tape:x:26:
sudo:x:27:aaronkilik
audio:x:29:pulse
dip:x:30:aaronkilik

Aṣẹ md5sums ti o wa ni isalẹ yoo ṣe agbekalẹ iye elile fun faili bi atẹle:

$ md5sum groups.csv

bc527343c7ffc103111f3a694b004e2f  groups.csv

Nigbati o ba gbiyanju lati yi awọn akoonu ti faili pada nipa yiyọ laini akọkọ,

$ md5sum groups.csv

46798b5cfca45c46a84b7419f8b74735  groups.csv

Iwọ yoo ṣe akiyesi pe iye elile ti yipada bayi, o tọka pe awọn akoonu ti faili nibiti o yipada.

Bayi, fi ila akọkọ ti faili pada, root: x: 0: ki o fun lorukọ mii si group_file.txt ati ṣiṣe aṣẹ ni isalẹ lati ṣe agbejade iye eli rẹ lẹẹkansi:

$ md5sum groups_list.txt

bc527343c7ffc103111f3a694b004e2f  groups_list.txt

Lati iṣẹjade ti o wa loke, iye elile tun jẹ kanna paapaa nigbati a ba ti fun lorukọmii faili naa, pẹlu akoonu atilẹba rẹ.

Pataki: Awọn akopọ md5 nikan jẹri/ṣiṣẹ pẹlu akoonu faili ju orukọ faili lọ.

Faili awọn faili_list.txt jẹ ẹda-ẹda ti groups.csv, nitorinaa, gbiyanju lati ṣagbeye iye elile ti awọn faili ni akoko kanna bii atẹle.

Iwọ yoo rii pe awọn mejeeji ni awọn iye elile ti o dọgba, eyi jẹ nitori wọn ni akoonu kanna kanna.

$ md5sum groups_list.txt  groups.csv 

bc527343c7ffc103111f3a694b004e2f  groups_list.txt
bc527343c7ffc103111f3a694b004e2f  groups.csv

O le ṣe atunṣe awọn iye (e) elile ti faili kan (s) sinu faili ọrọ ati itaja, pin wọn pẹlu awọn omiiran. Fun awọn faili meji loke, o le ṣe agbekalẹ aṣẹ ni isalẹ lati ṣe atunṣe awọn iye elile ti ipilẹṣẹ sinu faili ọrọ kan fun lilo nigbamii:

$ md5sum groups_list.txt  groups.csv > myfiles.md5

Lati ṣayẹwo pe awọn faili ko ti tunṣe lati igba ti o ṣẹda checksum, ṣiṣe aṣẹ atẹle. O yẹ ki o ni anfani lati wo orukọ faili kọọkan pẹlu\"O DARA".

Aṣayan -c tabi --check aṣayan sọ fun aṣẹ md5sums lati ka awọn akopọ MD5 lati awọn faili ki o ṣayẹwo wọn.

$ md5sum -c myfiles.md5

groups_list.txt: OK
groups.csv: OK

Ranti pe lẹhin ṣiṣẹda iwe ayẹwo, o ko le fun awọn faili lorukọ mii bibẹẹkọ o gba aṣiṣe\"Ko si iru faili tabi itọsọna", nigbati o ba gbiyanju lati ṣayẹwo awọn faili pẹlu awọn orukọ tuntun.

Fun apẹẹrẹ:

$ mv groups_list.txt new.txt
$ mv groups.csv file.txt
$ md5sum -c  myfiles.md5

md5sum: groups_list.txt: No such file or directory
groups_list.txt: FAILED open or read
md5sum: groups.csv: No such file or directory
groups.csv: FAILED open or read
md5sum: WARNING: 2 listed files could not be read

Erongba naa tun ṣiṣẹ fun awọn okun bakanna, ninu awọn aṣẹ ni isalẹ, -n tumọ si maṣe gbejade laini tuntun ti n tẹle:

$ echo -n "Tecmint How-Tos" | md5sum - 

afc7cb02baab440a6e64de1a5b0d0f1b  -

$ echo -n "Tecmint How-To" | md5sum - 

65136cb527bff5ed8615bd1959b0a248  -

Ninu itọsọna yii, Mo fihan ọ bi o ṣe le ṣe agbekalẹ awọn iye elile fun awọn faili, ṣẹda iwe ayẹwo fun ijẹrisi nigbamii ti iduroṣinṣin faili ni Lainos. Botilẹjẹpe a ti ri awọn ailaabo aabo ni algorithm MD5, awọn ifura MD5 ṣi wulo paapaa ti o ba gbẹkẹle ẹgbẹ ti o ṣẹda wọn.

Ṣiṣayẹwo awọn faili nitorina jẹ ẹya pataki ti mimu faili lori awọn eto rẹ lati yago fun gbigba lati ayelujara, titoju tabi pinpin awọn faili ti o bajẹ. Kẹhin ṣugbọn ko kere ju, bi o ṣe deede de ọdọ wa nipasẹ ọna kika asọye ni isalẹ lati wa iranlọwọ eyikeyi, o le ṣe daradara ṣe diẹ ninu awọn aba pataki lati mu ipo yii dara.