Compare two files' columns

Question

File1:

judi /export/home 76
judi /usr 83

File2:

judi /export/home 79
judi /usr 82

if COLUMN3 of File2 is greater that COLUMN3 of File1, the command should print File2's line; for example, for the files above, the command should print:

judi /export/home 79 

And not:

judi /usr 82

Answer 1

Using awk:

awk 'NR==FNR{x[NR]=$3}{if($3>x[FNR]){print}}' File1 File2

• NR==FNR{x[NR]=$3}: if the current record number is equal to the current file record number (i.e. we're processing the first file), assigns the value of the third field to x[NR];
• {if($3>x[FNR]){print}}: if the third field is greater than x[FNR], prints the record.

% cat File1
judi /export/home 76
judi /usr 83
% cat File2
judi /export/home 79
judi /usr 82
% awk 'NR==FNR{x[NR]=$3}{if($3>x[FNR]){print}}' File1 File2
judi /export/home 79