CSC352: Using Bash Scripts to Measure Program Execution Time

--D. Thiebaut (talk) 13:41, 11 September 2013 (EDT)

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This page illustrates how to use a Bash script to run a Java program multiple times while passing it a different parameter every time.

A simple Java Program

Note that the program gets the value of the variable N from the command line.

class PrintN {
 
     public static void main( String[] args ) {
 
         int N = Integer.parseInt( args[0] );
         System.out.println( "I got " + N );
     }
 
 }

Running the program 10 times from the command line

• Running the program above 10 times can be done as follows, from the command line:

   bash
   javac PrintN.java
   for i in 1 2 3 4 5 6 7 8 9 10 ; do
      java PrintN $i
   done

Running the program from a Bash script

The script is shown below:

#! /bin/bash
# runPrintN.sh
# 
javac PrintN.java
for i in 1 2 3 4 5 6 7 8 9 10 ; do
    java PrintN $i
done

Make sure you make the script executable before you call it:

 chmod a+x runPrintN.sh

You can now run the program 10 times with just one command:

 ./runPrintN.sh
 I got 1
 I got 2
 I got 3
 I got 4
 I got 5
 I got 6
 I got 7
 I got 8
 I got 9
 I got 10