Compare two files and print the common fields and their corresponding line numbers in the 1st file

Question

I have some raw data in one file say File1.txt

Colt McCoy QB CLE  135 222 1576    6   9   60.8%   74.51  
Josh Freeman QB TB 291 474 3451    25  6   61.4%   95.9  
Matt Cassel QB KC  262 450 3116    27  7   58.2%   93.0  
Michael Vick QB PHI    233 372 3018    21  6   62.6%   100.2  
Matt Schaub QB HOU 365 574 4370    24  12  63.6%   92.0  

File 2.txt has a list of names, one name per line

Josh  
Matt  

I want to get the output as Name and line number. For the above example it would be:

Josh: 2  
Matt: 3,5  

I have a command which gives me the list of names and the line numbers but I want to print it in the desired format above. My current command is

awk '{print $1, NR}' file1.txt | grep -f file2.txt

It shows

Josh 2
Matt 3
Matt 5

What can I do to make it print like the desired format?

Answer 1

awk alone can do this:

awk 'NR==FNR{seen[$1]=seen[$1]","NR; next};
{if ($1 in seen){printf("%s: %s\n", $1, substr(seen[$1], 2))}}' file2 file1

Answer 2

You can use diff -y file1 file2.

It will give you a side-by-side output from both files. It also has other options to parse your output.. Review the man page for more options.