HOW TO RUN PIG PROGRAMS - EXAMPLES

Pig programs can be run in three methods which work in both local and MapReduce mode. They are

• Script Mode
• Grunt Mode
• Embedded Mode

Let see each mode in detail 

Script Mode or Batch Mode: In script mode, pig runs the commands specified in a script file. The following example shows how to run a pig programs from a script file:

> cat scriptfile.pig
A = LOAD 'script_file';
DUMP A;
> pig scriptfile.pig

(pig script mode example)
(pig runs on top of hadoop)

Grunt Mode or Interactive Mode: The grunt mode can also be called as interactive mode. Grunt is pig's interactive shell. It is started when no file is specified for pig to run.

> pig
grunt> A = LOAD 'grunt_file';
grunt> DUMP A;

(pig grunt or interactive mode example)
(pig runs on top of hadoop)

You can also run pig scripts from grunt using run and exec commands.

grunt> run scriptfile.pig
grunt> exec scriptfile.pig

Embedded Mode: You can embed pig programs in java and can run from java.