how to integrate Bash with Java

Question

Can any body help me with how to compile a bash script as part of a java program. I am writing a simple java program that i want to use to invoke bash script commands.

my java code looks like the following:

    try{
            Process p = Runtime.getRuntime().exec("myscript.sh"); 
        BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream())); 

        String line = null;  

        while ((line = in.readLine()) != null){  
                    System.out.println(line); 
        }  
    }
    catch(IOException e){
        System.out.println(e.getMessage());
    }

and the "mysrcipt.sh" file is a simple script that contains the following lines

!/bin/bash

echo "enter your input followed by [ENTER]:"

read -e choice

echo $choice

My problem is, the program waits for an input at the read command in the script even if i enter multiple lines and press enter several times.

score 3 · Answer 1 · answered Sep 18 '12 at 21:47

You can use:

Process p = Runtime.getRuntime().exec("bash_script.sh"); 
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));  
String line = null;  
while ((line = in.readLine()) != null) {  
   // use bash script line output
}

score 1 · Accepted Answer · answered Sep 18 '12 at 21:51

1

It would be helpful to see some code showing what you're trying to accomplish.

Executing bash script in Java can be done using something like the following...

Runtime runtime = Runtime.getRuntime();
Process process = runtime.exec("YOUR COMMAND STRING");

List<String> lines = IOUtils.readLines(process.getInputStream());

answered Sep 18 '12 at 21:51

shortstuffsushi

2,271
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1

That's `org.apache.commons.io.IOUtils`, incidentally, not the standard Java libs. – DNA Sep 18 '12 at 22:15
Good point, I snatched that out of a piece of code I wrote a while ago and didn't check the imports. I +1'd Reimeus' answer for its more general form. – shortstuffsushi Sep 19 '12 at 00:47

score 1 · Answer 3 · edited May 23 '17 at 12:12

1

Runtime.exec() is what you need to execute your bash script, but be aware there are a few pitfalls. I found this to be a good article when starting to call external scripts.

It is written for a windows platform, but a lot of what is discussed is relevant to *nix as well.

how to integrate Bash with Java

!/bin/bash

3 Answers3