shell - AWK 将空列替换为下一行的列值

Question

我有以下示例文件，其中缺少列值，我想将其替换为同一列中的下一个可用值。

cat test.txt
11.2.0.1,ORA1,ORACLE
11.2.0.4,ORA2,ORACLE
11.2.0.3,ORA3,ORACLE
12.2.0.1,ORA4,ORACLE
,ORA5,ORACLE
,ORA6,ORACLE
12.2.0.2,ORA7,ORACLE
,MYS1,MYSQL
5.1,MYS2,MYSQL

这是我正在尝试做的事情:

 cat test.txt |awk '{printf("%s,%s,%s\n", $11,$3,$1);}'|awk -F',' 'BEGIN{OFS=","}
   {
        for (i=1; i<=NF; i++)
        if ($i=="")
            --Read next column value
            --If next column is null, read futhur next
            -- Assign next available value to $i
        print
    }'

预期输出:

11.2.0.1,ORA1,ORACLE
11.2.0.4,ORA2,ORACLE
11.2.0.3,ORA3,ORACLE
12.2.0.1,ORA4,ORACLE
12.2.0.2,ORA5,ORACLE
12.2.0.2,ORA6,ORACLE
12.2.0.2,ORA7,ORACLE
5.1,MYS1,MYSQL
5.1,MYS2,MYSQL

谢谢

Answer 1

你可以这样做:

awk -F, '$1==""{a[n++]=$0;next} n{for (i=0;i<n;i++) print $1 a[i]; n=0} 1' file

详情:

$1=="" {          # if the first field is empty
    a[n++]=$0     # store the whole line at index n and increment n
    next          # jump to the next line
}

n {                    # if n isn't zero
    for (i=0;i<n;i++)  # loop over stored lines indexes
        print $1 a[i]  # and print lines starting with the current first field
    n=0                # set n to 0
}

1  # true, print the current line