Bawo ni MO ṣe gba laini akọkọ ni Linux?
Yes, that is one way to get the first line of output from a command. There are many other ways to capture the first line too, including sed 1q (quit after first line), sed -n 1p (only print first line, but read everything), awk ‘FNR == 1’ (only print first line, but again, read everything) etc.
How do you get the first line in Unix?
Tẹ aṣẹ ori atẹle yii lati ṣafihan awọn laini 10 akọkọ ti faili kan ti a npè ni “bar.txt”:
- ori -10 bar.txt.
- ori -20 bar.txt.
- sed -n 1,10p /etc/group.
- sed -n 1,20p /etc/group.
- awk 'FNR <= 10' /etc/passwd.
- awk 'FNR <= 20' /etc/passwd.
- perl -ne'1..10 ati titẹ' /etc/passwd.
- perl -ne'1..20 ati titẹ' /etc/passwd.
Bawo ni o ṣe rii laini ikẹhin ati akọkọ ni Unix?
sed -n '1p;$p' faili. txt yoo tẹjade 1st ati ki o kẹhin ila ti faili. txt. Lẹhin eyi, iwọ yoo ni array ary pẹlu aaye akọkọ (ie, pẹlu atọka 0 ) jẹ laini akọkọ ti faili, ati aaye ikẹhin rẹ jẹ laini faili ti o kẹhin.
Bawo ni awọn ologbo ṣe ṣiṣe awọn laini 10?
Lati wo awọn ila diẹ ti o kẹhin ti faili kan, lo pipaṣẹ iru. iru ṣiṣẹ ni ọna kanna bi ori: iru iru ati orukọ faili lati wo awọn laini 10 ti o kẹhin ti faili yẹn, tabi tẹ iru -nọmba filename lati wo awọn laini nọmba ti o kẹhin ti faili naa.
Bawo ni MO ṣe yọ laini akọkọ kuro ni Unix?
lilo sed Òfin
Yiyọ laini akọkọ kuro lati faili titẹ sii nipa lilo pipaṣẹ sed jẹ taara taara. Aṣẹ sed ninu apẹẹrẹ loke ko nira lati ni oye. Paramita '1d' sọ fun pipaṣẹ sed lati lo iṣẹ 'd' (parẹ) lori nọmba laini '1'.
Bawo ni o ṣe ka faili kan ni Unix?
Lo laini aṣẹ lati lilö kiri si Ojú-iṣẹ, ati lẹhinna tẹ ologbo myFile. txt . Eyi yoo tẹ awọn akoonu ti faili si laini aṣẹ rẹ. Eyi jẹ imọran kanna bi lilo GUI lati tẹ lẹẹmeji lori faili ọrọ lati wo awọn akoonu rẹ.
Kini aṣẹ lati ṣafihan awọn laini 10 akọkọ ti faili ni Linux?
Aṣẹ ori, gẹgẹbi orukọ naa ṣe tumọ si, tẹ nọmba N oke ti data ti titẹ sii ti a fun. Nipa aiyipada, o tẹjade awọn laini 10 akọkọ ti awọn faili ti a ti sọ tẹlẹ. Ti o ba ti pese orukọ faili ju ọkan lọ lẹhinna data lati faili kọọkan ti wa ni iṣaaju nipasẹ orukọ faili rẹ.
Bawo ni MO ṣe ṣe afihan laini faili ni Unix?
Kọ iwe afọwọkọ bash lati tẹ laini kan pato lati faili kan
- awk : $>awk '{if(NR==LINE_NUMBER)' tẹjade $0}' file.txt.
- sed : $>sed -n LINE_NUMBERp file.txt.
- ori: $>ori -n LINE_NUMBER file.txt | iru -n + LINE_NUMBER Nibi LINE_NUMBER wa, nọmba ila wo ni o fẹ lati tẹ. Awọn apẹẹrẹ: Tẹjade laini kan lati faili ẹyọkan.
Bawo ni MO ṣe tẹjade laini keji ni Unix?
3 Idahun. iru ṣe afihan laini ikẹhin ti iṣelọpọ ori ati laini ikẹhin ti iṣelọpọ ori jẹ laini keji ti faili naa. PS: Nipa “kini o jẹ aṣiṣe pẹlu 'ori | iru' mi” pipaṣẹ - shelltel jẹ otitọ.
Kini NR ni aṣẹ AWK?
NR ni a AWK-itumọ ti ni oniyipada ati awọn ti o tọka nọmba ti awọn igbasilẹ ti n ṣiṣẹ. Lilo: NR le ṣee lo ni iṣipopada iṣẹ duro nọmba ti laini ti n ṣiṣẹ ati pe ti o ba lo ni END o le tẹ nọmba awọn laini ti a ti ṣiṣẹ patapata. Apeere : Lilo NR lati tẹ nọmba laini sita ninu faili nipa lilo AWK.
How does AWK work in Unix?
AWK command in Unix is used for pattern processing and scanning. It searches one or more files to see if they contain lines that match the specified patterns and then perform the associated actions.