How do I print the nth line in Linux?
M~N with “p” command prints every Nth line starting from line M. For example, 3~2p prints every 2nd line starting from 3rd line as shown below.
Koj nyeem kab nth hauv Unix li cas?
N is the line number that you want. For example, tail -n+7 input. txt | head -1 will print the 7th line of the file.
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- tail -n+N | head -1 : 3.7 sec.
- head -N | tail -1 : 4.6 sec.
- sed Nq;d : 18.8 sec.
How do I print the nth line of a file?
Sau ib tsab ntawv bash los luam ib kab ntawm ib cov ntaub ntawv
- awk : $>awk '{if(NR==LINE_NUMBER) print $0}' file.txt.
- sed : $>sed -n LINE_NUMBERp file.txt.
- head : $>head -n LINE_NUMBER file.txt | tail -n + LINE_NUMBER Ntawm no LINE_NUMBER yog, kab xov tooj twg koj xav luam tawm. Piv txwv: Sau ib kab los ntawm ib daim ntawv.
Kuv yuav grep cov ntaub ntawv hauv Linux li cas?
Yuav ua li cas siv grep hais kom ua hauv Linux
- Grep hais kom ua Syntax: grep [xaiv] Qauv [FILE…] …
- Piv txwv ntawm kev siv 'grep'
- grep foo /file/name. …
- grep -i "foo" /file/name. …
- grep ' yuam kev 123' /file/name. …
- grep -r “192.168.1.5” /etc/ …
- grep -w "foo" /file/name. …
- egrep -w 'word1|word2' /file/name.
Kuv yuav ua li cas grep tus lej tshwj xeeb hauv Linux?
Qhov kev xaiv -n (lossis -line-number) xaiv tells grep to show the line number of the lines containing a string that matches a pattern. When this option is used, grep prints the matches to standard output prefixed with the line number.
Dab tsi yog kev siv awk hauv Linux?
Awk yog ib qho khoom siv uas ua rau tus programmer sau me me tab sis cov kev pab cuam zoo nyob rau hauv daim ntawv ntawm cov nqe lus uas txhais cov qauv ntawv uas yuav tsum tau tshawb nrhiav nyob rau hauv txhua kab ntawm cov ntaub ntawv thiab qhov yuav tsum tau ua thaum muaj kev sib tw hauv ib qho kab. Awk feem ntau yog siv rau qauv scanning thiab ua.
Yuav ua li cas kuv phua ib txoj hlua nyob rau hauv bash?
Hauv bash, ib txoj hlua kuj tuaj yeem muab faib yam tsis siv $IFS hloov pauv. Qhov 'readarray' hais kom ua nrog -d kev xaiv yog siv los faib cov ntaub ntawv. Qhov kev xaiv -d yog siv los txheeb xyuas cov cim cais hauv cov lus txib xws li $IFS. Ntxiv mus, lub voj bash yog siv los luam cov hlua hauv daim ntawv sib cais.
Cov lus txib twg yuav luam tag nrho cov kab hauv cov ntaub ntawv?
Printing Kab los ntawm cov ntaub ntawv siv sed
sed "p" command cia peb luam cov kab tshwj xeeb raws li kab xov tooj lossis regex muab. sed nrog kev xaiv -n yuav txwv tsis pub luam tawm ntawm cov qauv tsis muaj / qhov chaw.
How do I extract a specific line from a text file in Unix?
Txhawm rau rho tawm cov kab ntau, hais kab 2 txog 4, koj tuaj yeem ua raws li nram no:
- $ sed -n 2,4p ib cofile. txt.
- npe 2,4! d ib cof. txt.
NR yog dab tsi hauv awk command?
NR yog AWK built-in variable thiab nws txhais tau tias muaj pes tsawg cov ntaub ntawv raug ua tiav. Kev Siv : NR tuaj yeem siv rau hauv kev ua haujlwm thaiv sawv cev rau cov kab uas tau ua tiav thiab yog tias nws siv hauv END nws tuaj yeem luam tawm cov kab tag nrho. Piv txwv : Siv NR los luam cov kab zauv hauv ib cov ntaub ntawv siv AWK.
How do I print a specific line using sed?
In this article of sed series, we will see how to print a particular line using the print(p) command of sed. Similarly, to print a particular line, put the line number before ‘p’. $ indicates the last line. !