Java Shell type Command Returns Different Path Than Expected During Testing

Challenges
1

I’m stuck on Stage #MG5. (The type builtin: executable files)

In this stage, we have to extend the type builtin to search for executable files using [PATH]

During testing, when I run

type my_exe

my program outputs:

my_exe is /tmp/baz/my_exe

but the test expects:

my_exe is /tmp/foo/my_exe

Here are my logs:

[tester::#MG5] Running tests for Stage #MG5 (The type builtin: executable files)
[tester::#MG5] [setup] export PATH=/tmp/quz:$PATH
[tester::#MG5] [setup] export PATH=/tmp/bar:$PATH
[tester::#MG5] [setup] export PATH=/tmp/foo:$PATH
[tester::#MG5] [setup] PATH is now: /tmp/foo:/tmp/bar:/tmp/quz:...
[tester::#MG5] [setup] Available executables:
[tester::#MG5] [setup] - my_exe
[tester::#MG5] Running ./your_program.sh
[your-program] $ type cat
[your-program] cat is /bin/cat
[tester::#MG5] ✓ Received expected response
[your-program] $ type cp
[your-program] cp is /bin/cp
[tester::#MG5] ✓ Received expected response
[your-program] $ type mkdir
[your-program] mkdir is /bin/mkdir
[tester::#MG5] ✓ Received expected response
[your-program] $ type my_exe
[your-program] my_exe is /tmp/baz/my_exe
[tester::#MG5] ^ Line does not match expected value.
[tester::#MG5] Expected: "my_exe is /tmp/bar/my_exe"
[tester::#MG5] Received: "my_exe is /tmp/baz/my_exe"
[your-program] $ 
[tester::#MG5] Assertion failed.
[tester::#MG5] Test failed

And here’s a snippet of my code:

import java.io.File;
import java.util.Arrays;
import java.util.Scanner;


public class Main {
    public static void main(String[] args) throws Exception {
        Scanner scanner = new Scanner(System.in);
        String input = "";
        String[] words;
        String command;
        String[] arguments;
        String argumentString; // to store rest of the arguments as a string
        boolean loop = true;

        while (loop) {
            System.out.print("$ ");

            input = scanner.nextLine().trim();
            words = input.split(" ");
            command = words[0];
            arguments = Arrays.copyOfRange(words, 1, words.length);
            argumentString = String.join(" ", arguments);

            switch (command) {
                case "exit":
                    if (arguments.length > 0 && !arguments[0].isEmpty())
                        System.exit(Integer.parseInt(arguments[0]));
                    else
                        System.exit(0);
                    break;

                case "echo":
                    System.out.println(argumentString);
                    break;

                case "type":
                    System.out.println(getType(argumentString));
                    break;

                default:
                    System.out.println(input + ": command not found");
            }
        }
    }

    public static String getType(String argument) {
        String[] builtin_commands = {"exit", "echo", "type"};
        String path_commands = System.getenv("PATH");
        String[] path_command = path_commands.split(File.pathSeparator);

        for (String command : builtin_commands) {
            if (command.equals(argument)) {
                return argument + " is a shell builtin";
            }
        }

        for (String path: path_command) {
            File file = new File(path, argument);

            if (file.exists()) {
                return argument + " is " + file.getAbsolutePath();
            }
        }

        return argument + ": not found";
    }
}
3

You are not checking that it is an executable file.

2 Likes
4

Thank you, I got tunnel visioned on the error.