Bash two text files comparision script

Question

Given two files, I want to write a shell script that reads each line from file1 and checks if it is there in file2. If a line is not found in file2 it should keep it lets say in a table TAB1. Also, if there any any additional lines in file2, which are not in file 2 it should keep it lets say in a table TAB2.

The files can contain words numbers or anything. For example :

file1 :

Hi!
1234
5678
1111
hello

file2:

1111
5678
1234
Hi!
hellothere

In this case there should be "hello" in TAB1, and "hellothere" in TAB2

If two files are equal I want to return with "files are equal" echo or something like that.

How can I do this? I've tried experimenting with diff, but without success.

Thanks in advance

Answer 1

First you need to sort each file. Then you need to use comm. Finally you can extract the columns that comm produces using awk. So something like this.

#! /bin/bash
sort 1ドル > 1ドル.sorted
sort 2ドル > 2ドル.sorted
comm -3 1ドル.sorted 2ドル.sorted > columns
if [ -s columns ]; then
 TAB1="$(awk '{ print 1ドル }' < columns)"
 TAB2="$(awk '{ print 2ドル }' < columns)"
 # do something with TAB1 and TAB2
else
 echo 1ドル and 2ドル contain the same data
fi

You would call this script like this:

./myscript file1 file2

after making the script executable with chmod.

• SSV: oh, that is nice. Any easy way to get those columns into variables/table? I need to perform extra operations on them before printing output
• Robin Green: @SSV OK I updated it
• SSV: well, everything is saved in TAB1 this way. TAB2 is empty (one TAB should contain additional entries, second missing entries).
• SSV: Partialy solved it by running comm twice - once with -13, and later with -23