Diff tools: diff, vimdiff, opendiff & twdiff

4 diff tools that can be executed from command line:

1. diff (/usr/bin/diff): pure CLI with text output, available in any terminals:
   

   /tmp > diff Hello.java Hello2.java
   
   1c1
   < public class Hello {
   ---
   > public class Hello2 {
   3c3
   <         System.out.println("Hello from " + Hello.class);
   ---
   >         System.out.println("Hello2 from " + Hello2.class);
   

   
   use -wub option to view contextual diff:

   /tmp > diff -wub Hello.java Hello2.java
   
   --- Hello.java 2014-09-24 13:16:55.000000000 -0400
   +++ Hello2.java 2014-09-24 13:18:01.000000000 -0400
   @@ -1,5 +1,5 @@
   -public class Hello {
   +public class Hello2 {
        public static void main(String[] args) {
   -        System.out.println("Hello from " + Hello.class);
   +        System.out.println("Hello2 from " + Hello2.class);
        }
    }
   



2. vimdiff (/usr/bin/vimdiff): part of vim, available in any terminals, pure CLI but blocks the current terminal:

   vimdiff Hello.java Hello2.java
   

   


3. opendiff (/usr/bin/opendiff): part of Mac OS xcode tools, launches a FileMerge window for diff and merge:  

   opendiff Hello.java Hello2.java
   

   
   
   



4. twdiff (/usr/local/bin/twdiff): command line tool of TextWrangler, and launches 3 separate TextWrangler windows (left, right and bottom) for diff and merge.

   twdiff Hello.java Hello2.java