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根据 grep 结果查找第三列中值最低的行

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根据 grep 结果查找第三列中值最低的行

我有一个文件，其中包含类似这样的行（包括其他数字）。这是输出的一部分

$ grep 1848 filename.csv

.csv假设 1848 位于第一列或第二列，我如何找到文件中包含最低第三列的前 5 行？

1848,2598,11.310694021273559
1848,2599,10.947275955606203
1848,2600,10.635270124233982
1848,2601,11.916564552040725
1848,2602,12.119810736845844
1848,2603,12.406661156256154
1848,2604,10.636275056472996
1848,2605,12.549890992708612
1848,2606,9.783802450936204
1848,2607,11.253697489670264
1848,2608,12.16385432290674
1848,2609,10.30355814063016
1848,2610,12.102525596913923
1848,2611,11.636595992818505
1848,2612,10.741178028606866
1848,2613,11.352414275107423
1848,2614,12.204860161717253
1848,2615,12.959915468475387
1848,2616,11.320652192610872

不幸的是，1848 有时也会出现在第三列，我需要忽略这一点：

6687,8963,9.241848677632822
6687,9111,10.537325656184889
6687,9506,11.315629894841848

答案1

使用 GNU 排序：

grep -E '(^1848|^[0-9]{4},1848)' file | sort -t, -k3n | head -n 5

（如果第一列的数字可能少于或多于 4 位，则替换{4}为+）

输出：

1848,2606,9.783802450936204
1848,2609,10.30355814063016
1848,2600,10.635270124233982
1848,2604,10.636275056472996
1848,2612,10.741178028606866

答案2

只需awk：

awk -F, 'BEGIN{PROCINFO["sorted_in"]="@ind_num_asc"} \
          $1==1848||$2==1848 {a[$3]=$0} END {for(i in a) print a[i]}' file.csv

  • BEGIN{PROCINFO["sorted_in"]="@ind_num_asc"}根据索引、数字以升序设置将创建的任何数组的顺序

  • $1==1848||$2==1848 {a[$3]=$0}检查第一个或第二个字段是否为 1848，如果是，则第三个字段（$3）作为数组a索引，其值为整个记录（$0）

  • 在中END {for(i in a) print a[i]}，我们简单地迭代键并打印值

为了仅获取 5 条记录，请head -5在末尾添加：

awk ... | head -5

只是为了完整性，你显然可以通过break在循环中加入一个微小的逻辑来获取前 5 条记录END，不需要tail：

awk -F, 'BEGIN{PROCINFO["sorted_in"]="@ind_num_asc"} \
          $1==1848||$2==1848 {a[$3]=$0} END {j=0; for(i in a) \
           {print a[i]; j++; if(j==5) break}}' file.csv

例子：

% cat file.txt
1848,2598,11.310694021273559
1848,2599,10.947275955606203
1848,2600,10.635270124233982
1848,2601,11.916564552040725
1848,2602,12.119810736845844
1848,2603,12.406661156256154
1848,2604,10.636275056472996
1848,2605,12.549890992708612
1848,2606,9.783802450936204
1848,2607,11.253697489670264
1848,2608,12.16385432290674
1848,2609,10.30355814063016
1848,2610,12.102525596913923
1848,2611,11.636595992818505
1848,2612,10.741178028606866
1848,2613,11.352414275107423
1848,2614,12.204860161717253
1848,2615,12.959915468475387
1848,2616,11.320652192610872

% awk -F, 'BEGIN{PROCINFO["sorted_in"]="@ind_num_asc"} $1==1848||$2==1848 {a[$3]=$0} END {for(i in a) print a[i]}' file.txt
1848,2606,9.783802450936204
1848,2609,10.30355814063016
1848,2600,10.635270124233982
1848,2604,10.636275056472996
1848,2612,10.741178028606866
1848,2599,10.947275955606203
1848,2607,11.253697489670264
1848,2598,11.310694021273559
1848,2616,11.320652192610872
1848,2613,11.352414275107423
1848,2611,11.636595992818505
1848,2601,11.916564552040725
1848,2610,12.102525596913923
1848,2602,12.119810736845844
1848,2608,12.16385432290674
1848,2614,12.204860161717253
1848,2603,12.406661156256154
1848,2605,12.549890992708612
1848,2615,12.959915468475387

% awk -F, 'BEGIN{PROCINFO["sorted_in"]="@ind_num_asc"} $1==1848||$2==1848 {a[$3]=$0} END {j=0; for(i in a) {print a[i]; j++; if(j==5) break}}' file.txt 
1848,2606,9.783802450936204
1848,2609,10.30355814063016
1848,2600,10.635270124233982
1848,2604,10.636275056472996
1848,2612,10.741178028606866

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