Comparing two CSV files in linux - linux

Question

I have two CSV files with me in the following format:
File1:
No.1, No.2
983264,72342349
763498,81243970
736493,83740940
File2:
No.1,No.2
"7938493","7364987"
"2153187","7387910"
"736493","83740940"
I need to compare the two files and output the matched,unmatched values.
I did it through awk:
#!/bin/bash
awk 'BEGIN {
FS = OFS = ","
}
if (FNR==1){next}
NR>1 && NR==FNR {
a[$1];
next
}
FNR>1 {
print ($1 in a) ? $1 FS "Match" : $1 FS "In file2 but not in file1"
delete a[$1]
}
END {
for (x in a) {
print x FS "In file1 but not in file2"
}
}'file1 file2
But the output is:
"7938493",In file2 but not in file1
"2153187",In file2 but not in file1
"8172470",In file2 but not in file1
7938493,In file1 but not in file2
2153187,In file1 but not in file2
8172470,In file1 but not in file2
Can you please tell me where I am going wrong?

Answer 1

Here are some corrections to your script:
BEGIN {
# FS = OFS = ","
FS = "[,\"]+"
OFS = ", "
}
# if (FNR==1){next}
FNR == 1 {next}
# NR>1 && NR==FNR {
NR==FNR {
a[$1];
next
}
# FNR>1 {
$2 in a {
# print ($1 in a) ? $1 FS "Match" : $1 FS "In file2 but not in file1"
print ($2 in a) ? $2 OFS "Match" : $2 "In file2 but not in file1"
delete a[$2]
}
END {
for (x in a) {
print x, "In file1 but not in file2"
}
}
This is an awk script, so you can run it like awk -f script.awk file1 file2. Doing so gives these results:
$ awk -f script.awk file1 file2
736493, Match
763498, In file1 but not in file2
983264, In file1 but not in file2
The main problem with your script was that it didn't correctly handle the double quotes around the numbers in file2. I changed the input field separator so that the double quotes are treated as part of the separator to deal with this. As a result, the first field $1 in the second file is empty (it is the bit between the start of the line and the first "), so you need to use $2 to refer to the first value you're interested in. Aside from that, I removed some redundant conditions from your other blocks and used OFS rather than FS in your first print statement.