Hello guys,

I have file1 and file2, two text files containing various lines.
I'm trying to find a way to compare file1 and file2:

If the first 7 characters of a line in file2 match the first 7 characters of a line in file1, then do not do anything.
Print out the lines of file1 (in file3, let's say) not found in file2 (according to this 7 characters rule).

I looked at "diff" but couldn't find a way to specify how similiar (first 7 characters matching) the lines have to be.


What utility should I use according to you?

Cheers !!

Hi,

Try this one,

awk 'NR==FNR{k=substr($0,1,7);a[k]=1;next;}{k=substr($0,1,7);if(!a[k]){print;}}' file2 file1 >file3

Thank you guys for your answers !

It could be shortened a little:

awk '{k=substr($0,1,7)} NR==FNR{a[k];next} !(k in a)' file2 file1>file3