Support cmdline_args when sys_exec.

user/src/bin/user_shell.rs

@@ -12,6 +12,7 @@ const DL: u8 = 0x7fu8;
 const BS: u8 = 0x08u8;
 
 use alloc::string::String;
+use alloc::vec::Vec;
 use user_lib::{fork, exec, waitpid};
 use user_lib::console::getchar;
 
@@ -26,11 +27,29 @@ pub fn main() -> i32 {
             LF | CR => {
                 println!("");
                 if !line.is_empty() {
-                    line.push('\0');
+                    let args: Vec<_> = line.as_str().split(' ').collect();
+                    let mut args_copy: Vec<String> = args
+                        .iter()
+                        .map(|&arg| {
+                            let mut string = String::new();
+                            string.push_str(arg);
+                            string
+                        })
+                        .collect();
+                    args_copy
+                        .iter_mut()
+                        .for_each(|string| {
+                            string.push('\0');
+                        });
+                    let mut args_addr: Vec<*const u8> = args_copy
+                        .iter()
+                        .map(|arg| arg.as_ptr())
+                        .collect();
+                    args_addr.push(0 as *const u8);
                     let pid = fork();
                     if pid == 0 {
                         // child process
-                        if exec(line.as_str()) == -1 {
+                        if exec(args_copy[0].as_str(), args_addr.as_slice()) == -1 {
                             println!("Error when executing!");
                             return -4;
                         }