AWK：比较两个 CSV 文件

Question

我有两个 CSV 文件，我想使用 AWK 比较它们并生成一个新文件。

file1.csv：

"no","loc" 
"abc121","C:/pro/in" 
"abc122","C:/pro/abc"
"abc123","C:/pro/xyz"
"abc124","C:/pro/in" 

file2.csv：

"no","loc" 
"abc121","C:/pro/in"
"abc122","C:/pro/abc"
"abc125","C:/pro/xyz"
"abc126","C:/pro/in" 

输出.csv：

"file1","file2","Diff" 
"abc121","abc121","Match" 
"abc122","abc122","Match" 
"abc123","","Unmatch" 
"abc124","","Unmatch" 
"","abc125","Unmatch" 
"","abc126","Unmatch"

Answer 1

awk 的一种方式：

script.awk：

BEGIN {
    FS = ","
}

NR>1 && NR==FNR {
    a[$1] = $2
    next
}

FNR>1 { 
    print ($1 in a) ? $1 FS $1 FS "Match" : "\"\"" FS $1 FS "Unmatch"
    delete a[$1] 
}

END {
    for (x in a) {
        print x FS "\"\"" FS "Unmatch"
    }
}

输出：

$ awk -f script.awk file1.csv file2.csv
"abc121","abc121",Match
"abc122","abc122",Match
"","abc125",Unmatch
"","abc126",Unmatch
"abc124","",Unmatch
"abc123","",Unmatch

Answer 2

我没有单独使用awk，但如果我理解你所问的要点，我认为这个长单行应该可以做到......

join -t, -a 1 -a 2 -o 1.1 2.1 1.2 2.2 file1.csv file2.csv | awk -F, '{ if ( $3 == $4 ) var = "\"Match\""; else var = "\"Unmatch\"" ; print $1","$2","var }' | sed -e '1d' -e 's/^,/"",/' -e 's/,$/,"" /' -e 's/,,/,"",/g'

说明：

• join 部分获取两个 CSV 文件，将它们连接到第一列（默认行为 join）并输出所有四个字段 (-o 1.1 2.1 1.2 2.2)，确保包含两个文件都不匹配的行(-a 1 -a 2)。
• awk 部分采用该输出并将第 3 列和第 4 列的组合替换为 "Match" 或 "Unmatch"，具体取决于它们是否确实匹配。我不得不根据您的示例对这种行为做出假设。
• sed 部分从输出 (-e '1d') 中删除“no”、“loc”标头并用开闭引号 (-e 's/^,/"",/' -e 's/,$/,""/' -e 's/,,/,"",/g') 替换空字段。最后一部分对您来说可能不是必需的。

编辑： 正如tripleee 指出的那样，如果两个初始文件未排序，则上述操作将失败。这是一个更新的命令来解决这个问题。它在将每个文件传递给加入之前将标题行和排序...

join -t, -a 1 -a 2 -o 1.1 2.1 1.2 2.2 <( sed 1d file1.csv | sort ) <( sed 1d file2.csv | sort ) | awk -F, '{ if ( $3 == $4 ) var = "\"Match\""; else var = "\"Unmatch\"" ; print $1","$2","var }' | sed -e 's/^,/"",/' -e 's/,$/,""/' -e 's/,,/,"",/g'