CODEWITHSUNDEEP
javabashunix
Anderson Green
Anderson Green

Reputation: 31850

Write to a program's standard input using a shell script

I want to send text input to the following Java program from the Unix (bash) command line, so that it will print the text that was entered. How can I write a shell script that will send the string "Print this" to the Java program?

import java.util.Scanner;
public class ReadStuff{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        System.out.println("Enter some text:");
        System.out.println(scan.nextLine());
    }
}

Upvotes: 1

Views: 2149

Answers (1)

Jon Lin
Jon Lin

Reputation: 143946

Use echo

echo "Print this" | java ReadStuff

Note that this will output:

Enter some text:
Print

Because you are calling Scanner.next() which reads the next word, not the entire line.

Or alternatively, if you have stuff in a file:

cat file_with_Print_this | java ReadStuff

Upvotes: 6

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