Remove Ctrl-C in stdio && remove sig_ctrlc(will be back in ch9)

os/src/fs/stdio.rs

@@ -23,12 +23,12 @@ impl File for Stdin {
             if c == 0 {
                 suspend_current_and_run_next();
                 continue;
-            } else if c == 3 {
+            }/* else if c == 3 {
                 // 3 is ctrl_c
                 //println!("[K] os/fs/stdio/read: Got Ctrl_C");
                 current_add_signal(SignalFlags::SIGINT);
                 break;
-            } else {
+            }*/ else {
                 break;
             }
         }

user/src/bin/sig_ctrlc.rs

@@ -1,39 +0,0 @@
-#![no_std]
-#![no_main]
-
-extern crate user_lib;
-use user_lib::console::getchar;
-use user_lib::*;
-
-const LF: u8 = 0x0au8;
-const CR: u8 = 0x0du8;
-
-fn func() {
-    println!("signal_handler: caught signal SIGINT, and exit(1)");
-    exit(1);
-}
-
-#[no_mangle]
-pub fn main() -> i32 {
-    println!("sig_ctrlc starting....  Press 'ctrl-c' or 'ENTER'  will quit.");
-
-    let mut new = SignalAction::default();
-    let old = SignalAction::default();
-    new.handler = func as usize;
-
-    println!("sig_ctrlc: sigaction");
-    if sigaction(SIGINT, &new, &old) < 0 {
-        panic!("Sigaction failed!");
-    }
-    println!("sig_ctrlc: getchar....");
-    loop {
-        let c = getchar();
-
-        println!("Got Char  {}", c);
-        if c == LF || c == CR {
-            break;
-        }
-    }
-    println!("sig_ctrlc: Done");
-    0
-}