Ngiwuphrinta kanjani umugqa wokuqala wefayela ku-Linux?

Ngiwubonisa kanjani umugqa wokuqala wefayela 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.

Ngiwuphrinta kanjani umugqa wokuqala ku-Unix?

Yebo, leyo yindlela eyodwa yokuthola umugqa wokuqala wokukhipha emyalweni. Ziningi ezinye izindlela zokuthwebula umugqa wokuqala futhi, kufaka phakathi i-sed 1q (yeka ngemva komugqa wokuqala), sed -n 1p (phrinta kuphela umugqa wokuqala, kodwa funda yonke into), awk 'FNR == 1' (phrinta kuphela umugqa wokuqala, kodwa futhi, funda yonke into) njll.

Ngiwuphrinta kanjani umugqa usuka efayeleni ku-Linux?

Bhala i-bash script ukuze uphrinte umugqa othile efayeleni

1. awk : $>awk '{if(NR==LINE_NUMBER) phrinta $0}' file.txt.
2. sed : $>sed -n LINE_NUMBERp file.txt.
3. ikhanda : $>head -n LINE_NUMBER file.txt | umsila -n + LINE_NUMBER Nansi i-LINE_NUMBER, iyiphi inombolo yomugqa ofuna ukuyiphrinta. Izibonelo: Phrinta umugqa kusuka efayeleni elilodwa.

Ngiwufunda kanjani umugqa wokuqala wefayela?

Sebenzisa ifayela. readline() ukufunda umugqa owodwa efayelini

Vula ifayela kumodi yokufunda nge-syntax ene-open(igama lefayela, imodi) njengefayela: ngemodi ethi “r” . Ifayela lekholi. umugqa wokufunda() ukuze uthole umugqa wokuqala wefayela futhi ugcine lokhu ku-variable first_line .

Ngilikhombisa kanjani inani lemigqa efayeleni ku-Unix?

Ungabala kanjani imigqa efayeleni ku-UNIX/Linux

1. Umyalo othi “wc -l” uma usetshenziswa kuleli fayela, ukhipha isibalo somugqa kanye negama lefayela. $ wc -l file01.txt 5 file01.txt.
2. Ukuze ukhiphe igama lefayela kumphumela, sebenzisa: $ wc -l < ​​file01.txt 5.
3. Ungakwazi njalo ukunikeza okukhipha umyalo kumyalo we-wc usebenzisa ipayipi. Ngokwesibonelo:

Uyini umyalo wokubonisa imigqa yokuqala yefayela eyi-10 ku-Linux?

Umyalo wekhanda, njengoba igama lisho, phrinta inombolo ephezulu engu-N yedatha yokokufaka okunikeziwe. Ngokuzenzakalelayo, iphrinta imigqa yokuqala eyi-10 yamafayela ashiwo. Uma kunikezwe igama lefayela elingaphezu kwelilodwa khona-ke idatha evela kufayela ngalinye yandulelwa igama lefayela layo.

Ngiwuthola kanjani umugqa wokuqala wefayela ku-Unix?

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

Ngiwuphrinta kanjani umugqa wokuqala we-awk?

Umyalo olandelayo othi `awk` usebenzisa i '-F' inketho kanye nesitatimende esinemibandela sokuphrinta amagama ababhali ngemuva kokweqa umugqa wokuqala. Lapha, inani le-NR lisetshenziswa kusimo uma. Lapha, “Igama Lombhali:nn” lizophrintwa njengomugqa wokuqala esikhundleni sokuqukethwe okuvela kulayini wokuqala.

Ngilifaka kanjani ifayela ku-Linux?

Ungawusebenzisa kanjani umyalo we-grep ku-Linux

1. I-Grep Command Syntax: grep [izinketho] PATTERN [IFILE...] ...
2. Izibonelo zokusebenzisa i-'grep'
3. grep foo /file/name. …
4. grep -i "foo" /file/name. …
5. grep 'iphutha 123' /file/name. …
6. grep -r “192.168.1.5” /etc/ …
7. grep -w “foo” /file/name. …
8. egrep -w 'word1|word2' /file/name.

Ngiwenza kanjani umugqa kusuka kufayela?

Umyalo we-grep usesha ifayela, ufuna okufanayo nephethini eshiwo. Ukuyisebenzisa thayipha grep , bese kuba iphethini esiseshayo kanye ekugcineni igama lefayela (noma amafayela) esicinga kuwo. Okukhiphayo yimigqa emithathu efayeleni equkethe izinhlamvu ezithi 'hhayi'.

Uwuthola kanjani umugqa kufayela le-Linux?

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.

Ngiliphrinta kanjani ifayela ku-Unix?

Ukuphrinta Amafayela

1. I-pr Command. I-pr command yenza ukufometha okuncane kwamafayela esikrinini setheminali noma ngephrinta. …
2. Imiyalo ye-lp ne-lpr. Umyalo i-lp noma i-lpr iphrinta ifayela ephepheni ngokuphambene nesibonisi sesikrini. …
3. I-lpstat kanye ne-lpq Commands. …
4. Imiyalo yokukhansela kanye ne-lprm.