Add args support and move tests to specific command line

Author: thomasarmel

README.md

@@ -90,3 +90,11 @@ dpkey module steals key input processing from DOS and converts scan code to asci
 about scan code: see [PS/2 Keyboard - OSDev Wiki](https://wiki.osdev.org/PS/2_Keyboard).
 
 ![sample2](https://github.com/o8vm/rust_dos/blob/images/dpkey.gif)
+
+## Tests
+
+To run the tests suite, you can type on your DOS emulator:
+
+```shell
+rust_dos.com test
+```

src/dos.rs

@@ -9,6 +9,8 @@ pub mod error_code;
 pub mod panic;
 pub mod math;
 pub mod cooperative_multitasking;
+pub mod env;
+
 use core::arch::asm;
 
 pub use alloc::string::String as String;

src/dos/env.rs

@@ -0,0 +1,61 @@
+use alloc::vec::Vec;
+use core::slice;
+
+fn command_tail<'a>() -> &'a [u8] {
+    unsafe {
+        let ptr = 0x80 as *const u8;
+        let len = *ptr as usize;
+        let bytes = slice::from_raw_parts(ptr.add(1), len);
+
+        let trimmed = bytes.iter()
+            .position(|&b| b == 0x0D)
+            .unwrap_or(len);
+
+        &bytes[..trimmed]
+    }
+}
+
+/// Returns the command line arguments as a vector of string slices.
+/// Handles quoted arguments and whitespace separation.
+///
+/// # Warning
+/// Unlike standard operating system, the first argument (index 0) is not the program name,
+/// but the first argument after the program name.
+pub fn args() -> Vec<&'static str> {
+    let mut args = Vec::new();
+    let line = command_tail();
+
+    let s = unsafe { core::str::from_utf8_unchecked(line) };
+    let bytes = s.as_bytes();
+    let len = bytes.len();
+    let mut i = 0;
+
+    while i < len {
+        while i < len && bytes[i].is_ascii_whitespace() {
+            i += 1;
+        }
+        if i >= len { break; }
+
+        let start = i;
+        let mut in_quotes = false;
+
+        while i < len {
+            let c = bytes[i];
+            if c == b'"' {
+                in_quotes = !in_quotes;
+                i += 1;
+                continue;
+            }
+            if !in_quotes && c.is_ascii_whitespace() {
+                break;
+            }
+            i += 1;
+        }
+
+        let end = i;
+        let token = s[start..end].trim_matches('"');
+        args.push(token);
+    }
+
+    args
+}

src/main.rs

@@ -1,22 +1,32 @@
+#![feature(abi_x86_interrupt)]
 #![no_std]
 #![no_main]
 
 extern crate alloc;
 
 mod dos_tests;
 
-use rust_dos::*;
 use crate::dos_tests::allocator_test::allocator_test;
+use crate::dos_tests::cooperative_multitasking_test::cooperative_multitasking_test;
 use crate::dos_tests::datetime::datetime_test;
 use crate::dos_tests::file::file_read_test;
-use crate::dos_tests::cooperative_multitasking_test::cooperative_multitasking_test;
+use rust_dos::*;
 
 entry!(main);
 
 fn main() {
-    allocator_test();
-    file_read_test();
-    datetime_test();
-    cooperative_multitasking_test();
-    println!("Hello, World!");
+    let args = dos::env::args();
+
+    if args.len() >= 1 && args[0] == "test" {
+        allocator_test();
+        file_read_test();
+        datetime_test();
+        cooperative_multitasking_test();
+    } else {
+        println!("Hello, World!");
+    }
 }
+
+
+
+