在awk中将文件1的一个字段与文件2的另一个字段进行比较

Question

I have two files file 1 and file 2. I want to see first column of file1 and go to that line number in file2.After that I am comparing $2 of file1 with $6 of file2. If matches then print "correct ans".I want to do this using awk.

file1.txt

1,B
3,C
2,A

file2.txt

Html,WeB,title,tech,Laravel,B
Html,WeB,title,tech,Laravel,D
Html,WeB,title,tech,Laravel,C

Output.txt

Question  1 is correct
Question 3 is correct
Question 2 is incorrect

I have tried to do this.

awk -F[","] 'NR==FNR{n=$1;b=$2}
  {if( NR==$1 && $6==b){printf "Question n is        correct "}
  else { printf "Question n is incorrect"}}' myfile rahulque

Answer 1

$ awk -F, 'FNR==NR{ans[NR]=$6;next} {print "Question",$1,"is",((ans[$1]==$2)?"":"in")"correct";}' file2.txt file1.txt
Question 1 is correct
Question 3 is correct
Question 2 is incorrect

How it works

• FNR==NR{ans[NR]=$6;next}

  For each line of the first file listed, file2.txt , we store the correct answer, $6 , in an array ans with the line number, NR , as the key. Then, we tell awk to skip the rest of the commands and jump to the next line.

• print "Question",$1,"is",((ans[$1]==$2)?"":"in")"correct"

  For every line of the second listed file, file1.txt , we print whether or not the answer for question $1 matches the correct answer specified in array a .

  In more detail, let's look at the ternary statement:

   (ans[$1]==$2)?"":"in" 

  The answer is correct if ans[$1]==$2 . In that case, the ternary statement returns an empty string. If the answer is incorrect, the ternary statement returns the string in . The string returned by the ternary statement is placed in front of the string correct to form the desired word.

Answer 2

I always found awk confusing so if I were to find a solution to this question I'd avoid awk all to together and just write a shell script like ...

#!/bin/sh

sort file1.txt | cut -d, -f2 > /tmp/file1.cut
cut -d, -f6 file2.txt > /tmp/file2.cut

count=0
while read -r a && read -r b <&3
do
        count=`expr $count + 1`
        if [ $a == $b ]
        then
                echo  "Question $count is correct"
        else
                echo  "Question $count is incorrect"
        fi
done < /tmp/file1.cut 3< /tmp/file2.cut

... this seems to work with the sample data your provided.

$ cat file1.txt
1,B
3,C
2,A
$ cat file2.txt
Html,WeB,title,tech,Laravel,B
Html,WeB,title,tech,Laravel,D
Html,WeB,title,tech,Laravel,C
$ ./correct.sh
Question 1 is correct
Question 2 is incorrect
Question 3 is correct
$ cat correct.sh
#!/bin/sh

sort file1.txt | cut -d, -f2 > /tmp/file1.cut
cut -d, -f6 file2.txt > /tmp/file2.cut

count=0
while read -r a && read -r b <&3
do
        count=`expr $count + 1`
        if [ $a == $b ]
        then
                echo  "Question $count is correct"
        else
                echo  "Question $count is incorrect"
        fi
done < /tmp/file1.cut 3< /tmp/file2.cut

I sure there is a better way to do this, like using awk, but I think the shell script approach is more flex able. For example if you wanted to count the number of incorrect and correct answers.