CODEWITHSUNDEEP
linuxbash
lacrosse1991
lacrosse1991

Reputation: 3162

Match up the contents of two files

I have two files: one contains a list of AP names, and another list contains AP names again, but this time the controller IP for each AP is listed before the AP's name.

File 1:

AP1
AP2
Ap3
AP4
Ap5
Ap6
...

File 2:

1.1.1.1,Ap1
2.2.2.2,Ap2
3.3.3.3,Ap3
4.4.4.4,Ap4
6.6.6.6,Ap6
...

How can I match up the names from file 1 with the names in file 2 so that the output resembles the following? 

1.1.1.1,Ap1
2.2.2.2,Ap2
3.3.3.3,Ap3
4.4.4.4,Ap4
IP Not Found,Ap5
6.6.6.6,Ap6

I was thinking that I could use the comm command, but I do not know of a good way to only compare the names and not the IPs. I could also just grep for every single name, but that would take forever (there are around 8,000 AP names).

Upvotes: 0

Views: 86

Answers (2)

hobbs
hobbs

Reputation: 239861

The join command will do the job (note that both files have to be sorted by AP name first; your example data already is, but if your real-world data isn't, run the first file through sort -f, and the second file through sort -f -t , -k 2).

join -i -t , -1 1 -2 2 -a 1 -o 2.1,1.1 -e "IP Not Found" file1.txt file2.txt

-i means ignore case, -t , means fields are separated by commas, -1 1 means join on the first (only) field of the first file; -2 2 means join on the second field of the second file. -a 1 means include rows from the first file that don't have any matches. -o 2.1,1.1 specifies the output format: the first field of the second file (IP), then the first field of the first file (AP). -e "IP Not Found" means to output "IP Not Found" in place of an empty field.

This will output

1.1.1.1,AP1
2.2.2.2,AP2
3.3.3.3,Ap3
4.4.4.4,AP4
IP Not Found,Ap5
6.6.6.6,Ap6

Upvotes: 3

Andrzej Pronobis
Andrzej Pronobis

Reputation: 36096

This awk snippet should do it:

awk 'BEGIN{FS=","}
     (FNR==NR){a[tolower($2)]=$0}
     (FNR!=NR){if (a[tolower($1)]!="") 
                 print a[tolower($1)]
               else 
                 print "IP Not Found," $1}' file2.txt file1.txt

producing in your case:

1.1.1.1,Ap1
2.2.2.2,Ap2
3.3.3.3,Ap3
4.4.4.4,Ap4
IP Not Found,Ap5
6.6.6.6,Ap6

Upvotes: 1

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