如何使用awk根据前三列合并两个文件 [英] How to merge two files based on the first three columns using awk

问题描述

我想使用前三列作为键将两个文件逐行合并为一个文件.示例:

I wanted to merge two files into a single one line by line using the first three columns as a key. Example:

file1.txt

file1.txt

a b c 1 4 7
x y z 2 5 8
p q r 3 6 9

file2.txt

file2.txt

p q r 11
a b c 12
x y z 13

我对以上两个文件的期望输出是:

My desired output for the above two files is:

a b c 1 4 7 12
x y z 2 5 8 13
p q r 3 6 9 11

每个文件中的列数不是固定的，它可能随行而变化.另外，每个文件中我的行数超过了27K.

The number of columns in each file is not fixed, it can vary from line to line. Also, I got more than 27K lines in each file.

未订购.他们唯一的事情是两个文件的前三个字段都相同.

They are not ordered. They only thing is that the first three fields are the same for both files.

推荐答案

加入前三个字段，其中字段数是可变的(四个或更多):

Join on the first three fields where the number of fields are variable (four or more):

{
    # get the forth field until the last
    for (i=4;i<=NF;i++)
        f=f$i" "

    # concat fields
    arr[$1OFS$2OFS$3]=arr[$1OFS$2OFS$3]f;
    # reset field string
    f=""    
}    
END {
    for (key in arr)
        print key, arr[key]    
}

运行方式:

$ awk -f script.awk file1 file2
a b c 1 4 7 12 
p q r 3 6 9 11 
x y z 2 5 8 13 

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