bash上的命令变量内的变量

Question

I'm trying to extract reference numbers for ip addresses which are not updated using BASH on centos, I have a CSV with not updated addresses (IPs_withoutrefn.csv) where I extract the second column, and then we compare this value against another CSV (IP-references.csv) to extract the reference number.

For this I was trying to do a variable in this way, but the output is always empty, if I try this command on shell without using a variable its working properly.

REFNO=$(grep "$IP" ../IP-references.csv | awk 'BEGIN{FS=OFS=";"}{sub(/\r$/,"");print $2"\r"}')

I already tried to convert this grep in a function, and to change the "$IP" inside the grep on different ways I read around here like ("^$IP;" or "$IP;" or ${IP} ... ) but the result its always same.

And this is the full code I'm using.

while IFS=";" read -r col1 col2

do

  #IP to variable#

        IP=$col2

        echo "$IP"

  #We search the IP and we extract the REFNO##

        REFNO=$(grep "$IP" ../IP-references.csv | awk 'BEGIN{FS=OFS=";"}{sub(/\r$/,"");print $2"\r"}')

        echo "$REFNO"

        echo "$IP"

done < "../IPs_withoutrefn.csv"

I hope its clearly enough for understanding, if not, please let me now.

IPs_withoutrefn.csv sample:

• ;1.1.1.1
• ;
• ;1.1.1.2

IP-references.csv sample

Client1;89345013745;modelno;status;node1;sect1;node2;sect2;;1.1.1.1;1.1.1.1;;;datexpiration;

Client2;89345013746;modelno;status;node1;sect1;node2;sect2;;1.1.1.2;1.1.1.2;;;datexpiration;

Client3;89345013747;modelno;status;node1;sect1;node2;sect2;;1.1.1.3;1.1.1.3;;;datexpiration;

Thank you.

Answer 1

cut -d ";" -f 2 IPs_withoutrefn.csv | xargs -I {} grep {} IP-references.csv

This would print all lines in IP-references that match IP adresses from the first file.

You can further improve the output by adding | cut -d ";" -f 1,11 | cut -d ";" -f 1,11 | cut -d ";" -f 1,11 to list in format

cut -d ";" -f 2 IPs_withoutrefn.csv  | xargs -I {} grep {} IP-references.csv | cut -d ";" -f 1,11

Client1;1.1.1.1

Client2;1.1.1.2

-d is for delimiter, -f for filed numbers