Execute Bash Command Within Java Program

Execute bash command within java program

To understand this, you first need to understand how you would run that command at a shell prompt.

$ sh -c "java -jar M1_MIAGE_PDL_VIZ_GROUPE3.jar menu"

Note where the double quotes are. The first argument is -c. The second argument is the stuff inside the quotes; i.e. java -jar M1_MIAGE_PDL_VIZ_GROUPE3.jar menu

Now we translate that into Java:

Process p = new ProcessBuilder(
   "/bin/sh", 
   "-c", 
   "java -jar M1_MIAGE_PDL_VIZ_GROUPE3.jar menu").start();

Having said that, the above doesn't actually achieve anything. Certainly, it doesn't open a fresh console window to display the console output etcetera. Unlike Windows "CMD.exe", UNIX / Linux shells do not provide console / terminal functionality. For that you need to use a "terminal" application.

For example, if you are using GNOME

Process p = new ProcessBuilder(
   "gnome-terminal", 
   "-e", 
   "java -jar M1_MIAGE_PDL_VIZ_GROUPE3.jar menu").start();

will (probably) do what you are trying to do.

execute bash script from java

Recently I used the below approach to execute a bash script.

 Process exec = getRuntime().exec("/home/user/test/test.sh");
        java.util.Scanner s = new java.util.Scanner(exec.getInputStream()).useDelimiter("\\A");
        System.out.println(s.next());

Whenever I tried getRuntime().exec("./home/user/test/test"); I got the exact error you were getting. java.io.IOException: Cannot run program "./home/user/test/test": error=2, No such file or directory.
To execute any command from any directory, please follow the below approach.

String []command ={"/bin/bash","-c", "ls"};
Process exec = getRuntime().exec(command,null,new 
     File("/home/user/test"));
java.util.Scanner s = new java.util.Scanner(exec.getInputStream()).useDelimiter("\\A");
System.out.println(s.next());

Hope this is some way helpful.

How to execute Shell Commands with Java and print the output directly while executing the command

Consider the following code.

ProcessBuilder pb = new ProcessBuilder("ping", "localhost");
pb.inheritIO();
try {
    Process p = pb.start();
    int exitStatus = p.waitFor();
    System.out.println(exitStatus);
}
catch (InterruptedException | IOException x) {
    x.printStackTrace();
}

I believe the above does what you want and I would say that the code is a lot simpler.

Refer to the javadoc for class java.lang.ProcessBuilder.

How to invoke a Linux shell command from Java

exec does not execute a command in your shell

try

Process p = Runtime.getRuntime().exec(new String[]{"csh","-c","cat /home/narek/pk.txt"});

instead.

EDIT::
I don't have csh on my system so I used bash instead. The following worked for me

Process p = Runtime.getRuntime().exec(new String[]{"bash","-c","ls /home/XXX"});

Execute shell commands by ProcessBuilder In java but seems nothing work

Java isn't bash, or shell. You don't really ever want to use exec, its rules are somewhat bizarre. It tries very haphazardly to split on spaces.

Instead, use ProcessBuilder, and specify a list of arguments, not the single string variant.

That whole pg_dump thing is a single argument and should not contain quotes - those quotes are 'eaten' by bash and tell bash to treat it all as a single argument; java isn't bash and just blindly passes them to the kubectl tool which doesn't know what it means.

All the other args (including --) are their own thing.

So..

List.of("/bin/kubectl", "exec", "-it", "pg-container", "-n", "data-prod", "--", "/bin/bash", "-c", String.format("pg_dump -U %s -d %s -n %s %s -f %s.sql", dbinfo.dbuser, dbinfo.dbname, dbinfo.schemaname, query_tables, dbinfo.output));

And pass that to the constructor of ProcessBuilder.

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