Isiphelo sangoLwesihlanu: Umjelo oMiselweyo

Wamkelekile kolunye uLwesihlanu ...

Lixesha lokuba wazi icandelo elincinci lesiphelo. Emva kokucingisisa ndaye ndagqiba kwelokuba ndenze iposti malunga imilambo esemgangathweni; Nangona izakuba ngaphezulu, ndicinga ukuba yinto ekufuneka yaziwe ngumntu wonke.

Umjelo oMiselweyo

Umjelo oMiselweyo Yenziwe ngamajelo onxibelelwano aliqela phakathi komsebenzisi kunye nesiphelo. Ezi zingeniso / ukuphuma "kwamajelo" abonisa okanye afake ulwazi xa kusenziwa umthetho.

Umzobo okhawulezayo kwimilambo esemgangathweni.

Unxibelelwano lwe-3 lwe-I / O zezi: stdin Igalelo eliqhelekileyo, Yima Imveliso esemgangathweni, kwiba Impazamo esemgangathweni.

stdin: Igalelo eliqhelekileyo

Igalelo elisezantsi yindlela esibamba ngayo ulwazi kumyalelo, nokuba kungenxa yemibhobho, ukuqondisa kwakhona, ikhibhodi, njl. Siyichonga ngesichazi sefayile 0.

Umzekelo we-stdin uya kuba:

uhlobo <uluhlu

Ithatha lonke ulwazi oluluhlu- kule meko amanani abhalwe ngokungacwangciswanga- kwaye xa uhambisa ifayile kumyalelo we-ls, iluhlela uluhlu lwamanani ngokwe-alfabhethi. Kulo mzekelo iiflegi azicaciswanga.

stdout: Iziphumo eziqhelekileyo

Imveliso esemgangathweni, njengoko igama layo lisitsho, ibonisa ukuphuma komyalelo ngekhonsoli. Ukuba sibhala ls lonke ulwazi olusibonisa kwiscreen sisiphumo esisezantsi. Imelwe yinkcazo 1.

Ngoku ndiza kuzama ukwenza i-stdin kunye ne-stdout ngesikripthi esibhalwe kwi-bash, kuba ndiyayithanda i-bash hahaha. 🙂

uvavanyo.sh

#! / bin / bash ukuba [-t 0]; emva koko echo "Usebenzisa i-stdout" elif [-t 1]; ke echo "Usebenzisa i-stdin" enye i-echo "Impazamo ye-Brutal" fi

Ngoku umfanekiso weskrini esibonisa indlela yokusebenzisa iskripthi. Xa uhambisa kwakhona okanye usebenzisa umbhobho kunye nokusetyenziswa kweskripthi vavanyo -t ukwazi ukuba kuphela iskripthi se-stdout esenziweyo, kwaye ukuba akunjalo kuyacaca ukuba yi-stdin.

Uvavanyo lwe-bash.sh ls | Uvavanyo lwe-bash.sh bash test.sh </ etc / passwd

Iskripthi ekuthethwa ngaso kunye neziphumo zaso ...

Khumbula ukuguqula umyalelo kunye nokuziqhelanisa ukuze ufunde.

stderr: Impazamo esemgangathweni

Impazamo esemgangathweni yindlela iinkqubo ezibonisa ngayo iimpazamo okanye isifo. Imelwe yinkcazo 2.

Ukuqonda umxholo, nantsi imeko: xa sifuna ukugcina impazamo kumyalelo, into yokuqala esicinga ngayo kukuthumela iziphumo kwisicatshulwa esicacileyo.

ls> ulwazi.txt

Oku kuyakusebenza, ulwazi lomyalelo luya kugcinwa kwifayile yokubhaliweyo ecacileyo. Kodwa xa ugcina impazamo, ayigcini, kodwa iyayibonisa kwiscreen kwaye ifayile yokubhaliweyo engenanto ayinanto.

Endaweni yoko ukuba sisebenzisa u-2> ukubonisa ukugcina i-stderr kwifayile:

ls foo 2> info.txt

Ngoku iya kugcina ulwazi lwempazamo kwifayile yokubhaliweyo.

Uninzi lwe Shell vumela i-stderr kunye ne-stdout ukuba igcinwe kumyalelo omnye womyalelo nge &> apho iFoo sisikhokelo esingekhoyo

ls Ukhuphelo lweFoo &> info.txt

Le fayile izakuqulatha ulwazi malunga nempazamo xa kuqhutywa i-ls kwi-Foo kwaye iya kudweliswa kwimikhombandlela phantsi koKhuphelo.

Kwaye okokugqibela, yintoni eyaziwayo 2> & 1?

Elula, eqondisa kwakhona i-stderr kwi-stdout. Oko kunye phakathi> kunye no-1 kuthetha ukuba iya kuphinda ithumele kwi-stdout. Ukuba ibingekho, ibizakuba yinto efana nale ... "phinda uthumele impazamo kwifayile yokuqala".

Kwaye oku kunokwenzeka ukuba uqondise kwakhona:

• stdout kwifayile
• stderr kwifayile
• stdout ukuya kwi-stderr
• stderr ukuya kwi-stdout
• stderr kunye stdout kwifayile
• phakathi kwabanye

Yiyo eyanamhlanje abantu. Sifunda kwaye siyabulela ngokusidlula. 😀