Compare 1 column bash
I generate a file everyday with three columns. I want my script to compare today's file with yesterdays file. It works currently but not the way i want it.the second and third column change every day but i dont want to know about that, i only want to know if the first column changes.
Here is the code that compares all columns and outputs the differences to a txt file.
grep -Fxvf $yesterday.txt $today.txt >> diff.txt
Does anyone know how to only compare the first column only??