rcore-tutorial/user/src/bin/user_shell.rs
2021-02-28 06:38:13 +08:00

138 lines
No EOL
4.6 KiB
Rust

#![no_std]
#![no_main]
extern crate alloc;
#[macro_use]
extern crate user_lib;
const LF: u8 = 0x0au8;
const CR: u8 = 0x0du8;
const DL: u8 = 0x7fu8;
const BS: u8 = 0x08u8;
use alloc::string::String;
use alloc::vec::Vec;
use user_lib::{
fork,
exec,
waitpid,
open,
OpenFlags,
close,
dup,
};
use user_lib::console::getchar;
#[no_mangle]
pub fn main() -> i32 {
println!("Rust user shell");
let mut line: String = String::new();
print!(">> ");
loop {
let c = getchar();
match c {
LF | CR => {
println!("");
if !line.is_empty() {
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');
});
// redirect input
let mut input = String::new();
if let Some((idx, _)) = args_copy
.iter()
.enumerate()
.find(|(_, arg)| arg.as_str() == "<\0") {
input = args_copy[idx + 1].clone();
args_copy.drain(idx..=idx + 1);
}
// redirect output
let mut output = String::new();
if let Some((idx, _)) = args_copy
.iter()
.enumerate()
.find(|(_, arg)| arg.as_str() == ">\0") {
output = args_copy[idx + 1].clone();
args_copy.drain(idx..=idx + 1);
}
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 {
// input redirection
if !input.is_empty() {
let input_fd = open(input.as_str(), OpenFlags::RDONLY);
if input_fd == -1 {
println!("Error when opening file {}", input);
return -4;
}
let input_fd = input_fd as usize;
close(0);
assert_eq!(dup(input_fd), 0);
close(input_fd);
}
// output redirection
if !output.is_empty() {
let output_fd = open(
output.as_str(),
OpenFlags::CREATE | OpenFlags::WRONLY
);
if output_fd == -1 {
println!("Error when opening file {}", output);
return -4;
}
let output_fd = output_fd as usize;
close(1);
assert_eq!(dup(output_fd), 1);
close(output_fd);
}
// child process
if exec(args_copy[0].as_str(), args_addr.as_slice()) == -1 {
println!("Error when executing!");
return -4;
}
unreachable!();
} else {
let mut exit_code: i32 = 0;
let exit_pid = waitpid(pid as usize, &mut exit_code);
assert_eq!(pid, exit_pid);
println!("Shell: Process {} exited with code {}", pid, exit_code);
}
line.clear();
}
print!(">> ");
}
BS | DL => {
if !line.is_empty() {
print!("{}", BS as char);
print!(" ");
print!("{}", BS as char);
line.pop();
}
}
_ => {
print!("{}", c as char);
line.push(c as char);
}
}
}
}