Ngiwuthola kanjani umugqa wokuqala wefayela ku-Unix?

Ukubheka imigqa embalwa yokuqala yefayela, thayipha igama lefayela lenhloko, lapho igama lefayela kuyigama lefayela ofuna ukulibuka, bese ucindezela . Ngokuzenzakalelayo, ikhanda likukhombisa imigqa yokuqala eyi-10 yefayela. Ungakushintsha lokhu ngokuthayipha igama lefayela elithi head -number, lapho inombolo iyinombolo yemigqa ofuna ukuyibona.

Ngiwufunda kanjani umugqa wokuqala wefayela?

Enye indlela yokufunda umugqa wokuqala wefayela isetshenziswa umsebenzi wokufunda () ofunda umugqa owodwa ukusuka emfudlaneni. Qaphela ukuthi sisebenzisa umsebenzi we-rstrip() ukususa uhlamvu lomugqa omusha ekugcineni komugqa ngoba i-readline() ibuyisela umugqa ngomugqa omusha olandelayo.

Ngiwucinga kanjani umugqa wefayela ku-Unix?

Gweba iyithuluzi le-Linux / Unix lomugqa womyalo elisetshenziselwa ukucinga uchungechunge lwezinhlamvu efayeleni elishiwo. Iphethini yokusesha umbhalo ibizwa ngokuthi isisho esivamile. Uma ithola okufanayo, iphrinta umugqa nomphumela. Umyalo we-grep uyasebenza lapho usesha amafayela amakhulu welogi.

Uwuthola kanjani umugqa wokugcina nowokuqala ku-Unix?

sed -n '1p;$p' ifayela. I-txt izophrinta eyoku-1 kanye nomugqa wokugcina wefayela. txt. Ngemva kwalokhu, uzoba ne-ary ary enenkambu yokuqala (okungukuthi, enenkomba 0 ) ewumugqa wokuqala wefayela , futhi inkambu yawo yokugcina ibe umugqa wokugcina wefayela .

Ngiyikhombisa kanjani imigqa yokuqala eyi-10 yefayela ku-Linux?

Thayipha umyalo wekhanda olandelayo ukuze ubonise imigqa yokuqala eyi-10 yefayela elibizwa ngokuthi “bar.txt”:

1. ikhanda -10 bar.txt.
2. ikhanda -20 bar.txt.
3. sed -n 1,10p /etc/group.
4. sed -n 1,20p /etc/group.
5. awk 'FNR <= 10' /etc/passwd.
6. awk 'FNR <= 20' /etc/passwd.
7. perl -ne'1..10 bese uphrinta' /etc/passwd.
8. perl -ne'1..20 bese uphrinta' /etc/passwd.

Ngibala kanjani inani lemigqa efayeleni ku-Linux?

Indlela elula kakhulu yokubala inani lemigqa, amagama, nezinhlamvu kufayela lombhalo ukusebenzisa umyalo we-Linux "wc" ku-terminal. Umyalo othi “wc” ngokuyisisekelo usho ukuthi “isibalo samagama” futhi ngamapharamitha azikhethela ahlukene umuntu angawusebenzisa ukubala inani lemigqa, amagama, nezinhlamvu efayeleni lombhalo.

Ngikusesha kanjani okuqukethwe kwefayela ku-Linux?

Ukusebenzisa i-grep Command Ukuthola Amafayela Ngokuqukethwe ku-Unix noma i-Linux

1. -i : Ziba ukuhlukaniswa kwecala kukho kokubili IMPENDULO (imeshi evumelekile, IVULELE, Iyunithi yezinhlamvu Evumelekile) kanye namafayela okufaka (ifayela lezibalo. c FILE. c FILE. C igama lefayela).
2. -R (noma -r ): Funda wonke amafayela ngaphansi kwenkomba ngayinye, ngokuphindaphindiwe.

Ngiyisebenzisa kanjani i-grep ukusesha ifayela?

Umyalo we-grep usesha ifayela, ufuna okufanayo nephethini eshiwo. Ukuyisebenzisa thayipha grep , bese kuba iphethini sifuna futhi ekugcineni igama lefayela (noma amafayela) esisesha kulo. Okukhiphayo yimigqa emithathu efayeleni equkethe izinhlamvu 'hhayi'.

Ngiyisebenzisa kanjani i-grep ukusesha ifolda?

Ukuze u-grep Wonke Amafayela Kuhla Lwemibhalo Ngokuphindaphindiwe, sidinga ukusebenzisa -R inketho. Lapho -R izinketho zisetshenziswa, Umyalo we-Linux grep uzosesha intambo enikeziwe kumkhombandlela oshiwo kanye nemibhalo engezansi ngaphakathi kwalolo lwazi. Uma lingekho igama lefolda elinikeziwe, umyalo we-grep uzosesha intambo ngaphakathi kohla lwemibhalo olusebenzayo lwamanje.

Ngiwuthola kanjani umugqa wokuqala nowokugcina wefayela ku-Linux?

Ngokuzenzakalelayo, ikhanda likukhombisa imigqa yokuqala eyi-10 yefayela. Ungakushintsha lokhu ngokuthayipha igama lefayela elithi head -number, lapho inombolo iyinombolo yemigqa ofuna ukuyibona. Ukuze ubheke imigqa embalwa yokugcina yefayela, sebenzisa umyalo womsila.

Ngiwuphrinta kanjani umugqa wesibili ku-Unix?

3 Izimpendulo. umsila ubonisa umugqa wokugcina wokuphuma kwekhanda futhi umugqa wokugcina wokuphuma kwekhanda umugqa wesibili wefayela. PS: Maqondana nokuthi "yini engalungile 'ngekhanda|msila' wami" umyalo - shelltel kulungile.

Iyini i-NR kumyalo we-AWK?

I-NR iyi-variable eyakhelwe ngaphakathi ye-AWK futhi yona isho inombolo yamarekhodi asetshenzwayo. Ukusetshenziswa : I-NR ingasetshenziswa kubhulokhi yesenzo imele inombolo yomugqa ocutshungulwayo futhi uma isetshenziswa kokuthi END ingaphrinta inombolo yemigqa ecutshungulwe ngokuphelele. Isibonelo : Ukusebenzisa i-NR ukuphrinta inombolo yomugqa kufayela usebenzisa i-AWK.

Ngiwubonisa kanjani umugqa we-10 wefayela?

Ngezansi kunezindlela ezintathu ezinhle zokuthola umugqa we-nth wefayela ku-Linux.

1. ikhanda / umsila. Ukusebenzisa nje inhlanganisela yemiyalo yekhanda nomsila cishe kuyindlela elula kakhulu. …
2. sed. Kunezindlela ezimbalwa ezinhle zokwenza lokhu nge-sed. …
3. awu. I-awk ine-NR eyakhelwe ngaphakathi egcina umkhondo wezinombolo zemigqa yefayela/yokusakaza.

Ulifunda kanjani ifayela ku-Unix?

Sebenzisa umugqa womyalo ukuze uye ku-Desktop, bese thayipha ikati i-myFile. txt . Lokhu kuzophrinta okuqukethwe kwefayela emugqeni wakho womyalo. Lona umqondo ofanayo nokusebenzisa i-GUI ukuze uchofoze kabili ifayela lombhalo ukuze ubone elikuqukethe.