英文:
grep stop at first match
问题
You can use the -m option with grep to specify the maximum number of matches. To stop grep at the first match of ${A57}, you can use the following command:
grep -o -m 1 "${A57}.*${A29}${A14}"
This will give you the desired output:
${A57}${A37}${A18}${A44}${A15}${A28}${A29}${A29}${A29}${A29}${A14}
The -m 1 option tells grep to stop after the first match is found.
英文:
I want to grep a file that stops at the first match, example:
${A57}${A17}${A23}${A20}${A35}${A57}${A33}${A24}${A38}${A38}${A24}${A17}${A57}${A33}${A23}${A38}${A18}${E52}${A28}${A28}${A28}${A25}${A38}${A22}${A50}${A30}${A57}${A37}${A18}${A44}${A15}${A28}${A29}${A29}${A29}${A29}${A14}
When I use grep -o "${A57}.\*${A29}${A14}" I obtain this output:
${A57}${A17}${A23}${A20}${A35}${A57}${A33}${A24}${A38}${A38}${A24}${A17}${A57}${A33}${A23}${A38}${A18}${E52}${A28}${A28}${A28}${A25}${A38}${A22}${A50}${A30}${A57}${A37}${A18}${A44}${A15}${A28}${A29}${A29}${A29}${A29}${A14}
Now my question is how can I stop grep with the first match of '${A57}' so that I have this output:
${A57}${A37}${A18}${A44}${A15}${A28}${A29}${A29}${A29}${A29}${A14}
答案1
得分: 3
You can use the following translated code snippets:
使用任何 sed：
$ sed -n 's/.*\(${A57}.*${A29}${A14}\).*//p' file
${A57}${A37}${A18}${A44}${A15}${A28}${A29}${A29}${A29}${A29}${A14}
或者使用支持 gensub() 的 GNU awk：
$ awk '{print gensub(/.*(${A57}.*${A29}${A14}).*/,"\",1)}' file
${A57}${A37}${A18}${A44}${A15}${A28}${A29}${A29}${A29}${A29}${A14}
英文:
You're trying to use the wrong tool. Using any sed:
$ sed -n 's/.*\(${A57}.*${A29}${A14}\).*//p' file
${A57}${A37}${A18}${A44}${A15}${A28}${A29}${A29}${A29}${A29}${A14}
or an awk that supports gensub() such as GNU awk:
$ awk '{print gensub(/.*(${A57}.*${A29}${A14}).*/,"\",1)}' file
${A57}${A37}${A18}${A44}${A15}${A28}${A29}${A29}${A29}${A29}${A14}
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