Taw qhia
Lub pob pov thawj rau nws yog ib qhov kev pom hexadecimal. Koj tuaj yeem siv cov lus hexadecimal thaum debugging ib qho kev pab cuam los yog rov qab tsim dua ib qho kev pab cuam.
Piv txwv li, ntau cov ntawv tawm tswv yim muaj ib qho cim rau nws ua kom pom lawv hom. Yog tias koj tabtom sim nyeem cov ntaub ntawv uas siv ib qho kev pab cuam thiab vim qee qhov tsis tsim nyog thwj, nws yuav yog tias cov ntaub ntawv tsis yog nyob rau hauv hom koj xav tau.
Yog tias koj xav pom seb qhov kev pab cuam ua haujlwm li cas thiab koj tsis muaj lub hauv paus los yog ib qho software uas thim rov qab rau cov neeg ua haujlwm, koj tuaj yeem saib lub pob pov thawj rau kev sim thiab ua haujlwm txog dab tsi tshwm sim.
Hexadecimal Yog Dab Tsi?
Computers xav tias nyob hauv binary . Txhua tus cwj pwm, tus naj npawb, thiab cov cim tau hais los ntawm qhov kev xaiv binary lossis ntau tus binary.
Cov neeg quavntsej, tabsis, yuav tsum xav txog decimal.
| Txhiab | Pua pua | Kaum | Chav nyob |
| 1 | 0 | 1 | 1 |
Raws li tib neeg, peb cov lej qis tshaj plaws hu ua units thiab sawv cev rau cov najnpawb 0 txog 9. Thaum peb mus txog 10 peb rov pib dua cov kab ntawv rov qab rau 0 thiab ntxiv 1 mus rau kaum-kaum sab (10).
| 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 |
| 1 | 0 | 0 | 1 | 0 | 0 | 0 | 1 |
Hauv binary, tus xov tooj qis tshaj tsuas sawv cev 0 thiab 1. Thaum twg peb tuaj dhau los 1 peb muab 1 tawm ntawm kab ntawv 2 thiab ib qho 0 hauv kab 1. Thaum koj xav sawv cev 4 koj muab tso rau 1 ntawm 4 kem thiab pib dua 2's thiab 1's sab.
Yog li ntawd los sawv cev 15 koj yuav muaj 1111 uas yog rau 1 yim, 1 plaub, 1 ob thiab 1 leej. (8 + 4 + 2 + 1 = 15).
Yog tias peb tau saib cov ntaub ntawv hauv binary nws yuav loj kawg kiag thiab tsis muaj peev xwm ua kom paub meej.
Cov kauj ruam tom ntej ntawm binary yog octal, uas siv 8 raws li lub hauv paus tooj.
| 24 | 16 | 8 | 1 |
| 0 | 1 | 1 | 0 |
Nyob hauv ib qho kev txawj ntse kav kaum sab saud pib ntawm 0 mus rau 7, feem thib ob yog 8 txog 15, feem peb sab 16 mus rau 23 thiab plaub sab 24 mus rau 31 thiab ntxiv rau. Whilst feem ntau yooj yim nyeem dua binary feem coob nyiam siv hexadecimal.
Hexadecimal siv 16 raws li lub hauv paus tooj. Tam sim no qhov no yog qhov twg nws tau ruam tag vim tias tib neeg peb xav txog cov lej li 0 txog rau 9 xyoos.
Yog li dab tsi siv rau 10, 11, 12, 13, 14, 15? Lo lus teb yog cov tsiaj ntawv.
- 0 = 0
- 1 = 1
- 2 = 2
- 3 = 3
- 4 = 4
- 5 = 5
- 6 = 6
- 7 = 7
- 8 = 8
- 9 = 9
- 10 = A
- 11 = B
- 12 = C
- 13 = D
- 14 = E
- 15 = F
Qhov nqi 100 yog li ntawm 64. Koj yuav tsum tau muaj 6 ntawm 16s kem uas yog theem 96 thiab tom qab 4 nyob rau hauv cov kem chav ua 100.
Tag nrho cov cim hauv ib daim ntawv yuav raug muab los ntawm ib qho kev ua hexadecimal. Cov txiaj ntsim zoo txhais li cas yog nyob ntawm cov ntaub ntawv ntawm nws tus kheej. Cov hom ntawv ntawm cov ntaub ntawv yog muab los ntawm qhov ua tau zoo tias nws yog qhov pib thaum pib ntawm cov ntaub ntawv.
Nrog kev paub ntawm qhov sib lawv liag ntawm nws qhov pib ntawm cov ntaub ntawv, koj tuaj yeem ua haujlwm ntawm hom ntaub ntawv nyob rau hauv. Saib cov ntaub ntawv hauv lub pob tawb tau pab koj nrhiav cov neeg thaum uas tsis pom thaum cov ntaub ntawv loaded rau hauv ib phau ntawv nyeem.
Yuav Ua Li Cas Tsim Tsim Ib Hex Pob Tsum Siv Linux
Los ua ib qho pob zeb siv hneev siv Linux siv qhov hais kom ua hexdump.
Mus tso saib cov ntaub ntawv raws li hex rau lub davhlau ya nyob twg (tus tso zis tso) khiav cov lus qhia nram qab no:
hexdump filename
Piv txwv
hexdump image.png
Lub neej tso zis yuav tso cov kab nab npawb (hauv hom ntawv hexadecimal) thiab tom qab 8 poob ntawm 4 hexadecimal qhov tseem ceeb rau ib kab.
Piv txwv li:
00000000 5089 474e 0a0d 0a1a 0000 0d00 4849 5244
Koj tuaj yeem muab cov keyboards sib txawv los hloov cov zis tso tawm. Piv txwv specifying qhov rho tawm b rho tawm yuav ua 8 tus lej offset raws li 16 rau peb sab, xoom lawm, bytes ntawm cov ntaub ntawv tawm tswv yim nyob rau hauv octal hom.
hexdump -b image.png
Yog li cov lus saum toj no yuav tam rau tam sim no raws li nram no:
00000000 211 120 116 107 015 012 032 012 000 000 000 015 111 110 104 122
Qhov saum toj no yog hu ua one-byte octal zaub.
Lwm txoj kev los saib cov ntaub ntawv yog nyob hauv ib qho-byte cim zaub uas siv cov kev hloov ciaj cias.
hexdump -c image.png
Qhov no dua cov lus tshaj tawm, tiam sis lub sijhawm no ua raws li los ntawm kaum rau qhov chaw sib cais, peb sab, qhov chaw muaj cov lus sau tawm ntawm ib kab.
Lwm cov kev xaiv muaj xws li Canonical hex + ascii zaub uas tau muab tso tawm kom pom tias siv cov C rho tawm thiab ob-byte decimal zaub uas tau muab tso tawm kom pom tias siv cov kev hloov dauv. Tus rho tawm o hloov tau siv los tso saib ob-byte octal zaub. Thaum kawg cov minux x hloov tau siv los tso saib ob-byte hexadecimal zaub.
hexdump-C image.png
hexdump -d image.png
hexdump -o image.png
hexdump -x image.png
Yog hais tias tsis muaj cov hom ntawv saum toj no nplua koj xav tau kev pab rau koj siv cov rho tawm e mus qhia seb yog hom twg.
Yog tias koj paub ib cov ntaub ntawv muaj ntaub ntawv ntev heev thiab koj tsuas xav pom thawj ob peb lub cim los txiav txim seb nws hom koj siv tau lub -n mus rau kom qhia ntau npaum li cas ntawm cov ntaub ntawv mus tso rau hauv hex.
hexdump -n100 image.png
Cov lus txib saum toj no qhia txog thawj 100 bytes.
Yog tias koj xav hla ib feem ntawm cov ntaub ntawv koj siv tau rho tawm qhov kev rho tawm kom tau ib qho pib ntawm pib.
hexdump -s10 image.png
Yog tias koj tsis muab ib daim ntawv filename rau hauv cov ntawv nyeem los ntawm cov qauv tawm tswv yim.
Tsuas nkag rau cov lus txib nram qab no:
hexdump
Tom qab ntawd nkag mus rau cov ntawv nyeem rau hauv cov txheej txheem tawm tswv yim thiab tiav los ntawm kev txiav luam yeeb. Lub hex yuav muab tso tawm rau cov zis tso zis.
Txoj kev xaus
Lub chaw hexdump yog obviously ib qho cuab tam haib thiab koj yuav tsum twv yuav tsum tau nyeem daim ntawv qhia kev rau tag nrho mus rau grips nrog tag nrho cov nta.
Koj yuav tsum tau muaj kev nkag siab zoo txog yam koj tab tom nrhiav thaum nyeem cov zis.
Txhawm rau saib cov nplooj ntawv qhia txog cov lus qhia nram qab no:
txiv neej hexdump