Comparing Files in Linux

There are two files called “file1.txt" and “file2.txt" both have a list of words. Now we want to check which words are extra in "file1.txt" and are not in "file2.txt" 

                 Diff analyzes two files and prints the lines that are different. Essentially, it outputs a set of instructions for how to change one file in order to make it identical to the second file.

Comparing the content of  files using:

• diff  file1 file2   -  Compare two files 
•  colordiff file1 file2  -  Same as diff output with color and syntax highlight 
•  sdiff  file1  file2  -  Side-by-Side comparison 
•  vimdiff  file1 file2  -  Highlighted difference in vim
• wdiff  file1 file2  -  Compare  files word by word

Files we are going to compare:

cat file.txt

cat file2.txt

 diff  command output:

diff file.txt file2.txt

 1c1 -  Line no. of file 1 – Action  - Line no. of file 2

Action:-  a -  Add, c – Change, d – Delete, < - Line from file1,  > - Line from file2

Result:-  

• 1c1  -  file.txt line no. 1 changed in file2.txt
•  6d5  -  file.txt line no. 6 deleted in file2.txt
• 11c10  -  file.txt line no. 11 changed in files2.txt 

colordiff  command output:

apt-get install colordiff (for installing colordiff)

colodiff  file.txt  file2.txt

 Same as diff output with color and syntax highligtht

sdiff command output:

sdiff  file.txt  file2.txt

Side-by-Side comparison

Actions:- 

| - Differing lines

 < - Line in file1 but not in file2

 > - Line in file2 but not in file1

vimdiff  command output:

vimdiff  file.txt  file2.txt

• Ctrl+w w  -  Goto next window
• :q  -  Quit (close) current window 
• :qa  -  Quit all 
• :qa!  -  Force quit all 

wdiff command output:

apt-get install wdiff (for install wdiff)

wdiff  fle.txt  file2.txt

Actions:

•  It covers the removed word / line with [- -]
• It covers the added word / line with {+ +} 

wdiff command with colordiff:

wdiff  file.txt  file2.txt | colordiff