Display lines from file1 that are not in file2

Shell Programming and Scripting
1

Hi there,

I know the command diff but what I want is slightly different.
I have two files containing lines that look like md5sums.

file1

5a1e8cee2eb2157c86e7266ee38e47c3  /tmp/file1
a254c48bdd064a40b82477b9fa5be05d  /tmp/file2
2d57c72ec898acddf8a6bacb3f821572  /tmp/file3
335b92f62ad1f2627806d55fb71dd573  /tmp/file4

file2

5a1e8cee2eb2157c86e7266ee38e47c3  /tmp/file1
5365eed4fd479dbee61146548b02247a  /tmp/file2
b05b600288d4adba461bf8f32b6161a2  /tmp/file2
4853428d204c2c9a4d49d7eaea549cc8  /tmp/file3
2d57c72ec898acddf8a6bacb3f821572  /tmp/file3
d5c5a0927f5fb67c15af1497457126f8  /tmp/file4
4c5c81b31bbc752b7d89735bda996652  /tmp/file4

I highlighted in red lines from file1 that exist in file2 and I would like a command that display the lines in file1 that do NOT appear in file2. In my example, it would be:

a254c48bdd064a40b82477b9fa5be05d  /tmp/file2
335b92f62ad1f2627806d55fb71dd573  /tmp/file4

Can you help me?
Cheers
Santiago

2 
 comm -23 <(sort file1) <(sort file2)

I hope you don't care about lines' ordering.

3

Something like this?

awk 'NR==FNR{a[$0];next} !($0 in a) ' file2 file1
4 
  awk 'BEGIN { while (getline<"file2") { arr[$0]++}} { if(!($0 in arr)) {print}}'  file1

That is the code almost like that of Franklin ....

5 
grep -vf file2 file1
6 
awk 'NR==FNR{a[$0]++;next} !a[$0] ' file2 file1