Cov txheej txheem:

NR txhais li cas hauv awk?
NR txhais li cas hauv awk?

Video: NR txhais li cas hauv awk?

Video: NR txhais li cas hauv awk?
Video: Ua siab hnov qab kuv mus by zuag lauj & pov vwj nkauj tawm tshiab 2020 2024, Kaum ib hlis
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NR yog a AWK built-in variable thiab nws txhais tau tias muaj pes tsawg tus ntawm cov ntaub ntawv tau ua tiav. Kev siv: NR can siv nyob rau hauv kev txiav txim block sawv cev rau tus naj npawb ntawm kab ua tiav thiab yog tias nws yog siv hauv END nws ua tau luam tus naj npawb ntawm kab ua tiav. Piv txwv: siv NR los luam kab zauv hauv ib cov ntaub ntawv siv AWK.

Ntawm no, NR Linux yog dab tsi?

NR yog rau tus naj npawb ntawm cov ntaub ntawv hauv cov ntaub ntawv nkag. NR yog tus naj npawb ntawm cov ntaub ntawv tam sim no / kab, tsis yog tus naj npawb ntawm cov ntaub ntawv hauv cov ntaub ntawv. Tsuas yog hauv END thaiv (lossis ntawm kab kawg rau cov ntaub ntawv) yog nws cov kab hauv cov ntaub ntawv.

Ib sab saum toj no, FNR yog dab tsi hauv Unix? In awk, FNR hais txog tus lej sau (feem ntau yog kab xov tooj) hauv cov ntaub ntawv tam sim no thiab NR hais txog tag nrho cov ntaub ntawv sau tseg. Cov qauv no feem ntau yog siv los ua cov haujlwm ntawm thawj cov ntaub ntawv nkaus xwb.

Tsuas yog li ntawd, dab tsi yog awk hais kom ua hauv Linux nrog piv txwv?

AWK command in Unix / Linux nrog piv txwv . Awk yog ib hom lus scripting siv los tswj cov ntaub ntawv thiab tsim cov ntawv ceeb toom. Cov aw command programming lus yuav tsum tsis txhob muab sau ua ke, thiab tso cai rau tus neeg siv siv cov kev hloov pauv, cov lej ua haujlwm, txoj hlua ua haujlwm, thiab cov neeg ua haujlwm muaj tswv yim.

Koj siv gawk li cas?

gawk hais kom ua yuav siv tau rau:

  1. Scans ib kab ntawv los ntawm kab.
  2. Splits txhua input kab rau hauv teb.
  3. Sib piv cov kab nkag / teb rau cov qauv.
  4. Ua haujlwm ntawm cov kab sib tw.
  5. Hloov cov ntaub ntawv.
  6. Tsim cov ntawv ceeb toom formatted.
  7. Format cov kab tawm.
  8. Arithmetic thiab txoj hlua ua haujlwm.

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