Implement getpass()

Also make fields in `termios` public; required for modifying them.

There's an new type of test: `EXPECT_INPUT_BINS`. These require a `.exp`
file to be present along with the `.c` file. The `.exp` file takes the
produced binary as an argument and sends input to the program. This is
useful for testing functions like `getpass()`.

src/header/unistd/mod.rs

@@ -11,7 +11,9 @@ use crate::{
     c_str::CStr,
     header::{
         crypt::{crypt_data, crypt_r},
-        errno, fcntl, limits,
+        errno, fcntl,
+        limits::{self, PASS_MAX},
+        stdio,
         stdlib::getenv,
         sys_ioctl, sys_resource, sys_time, sys_utsname, termios,
         time::timespec,
@@ -450,9 +452,51 @@ pub extern "C" fn getpagesize() -> c_int {
         .expect("page size not representable as type `int`")
 }
 
-// #[no_mangle]
-pub extern "C" fn getpass(prompt: *const c_char) -> *mut c_char {
-    unimplemented!();
+#[no_mangle]
+pub unsafe extern "C" fn getpass(prompt: *const c_char) -> *mut c_char {
+    let tty = stdio::fopen(c_str!("/dev/tty").as_ptr(), c_str!("w+e").as_ptr());
+
+    if tty.is_null() {
+        return ptr::null_mut();
+    }
+
+    let fd = stdio::fileno(tty);
+
+    let mut term = termios::termios::default();
+    termios::tcgetattr(fd, &mut term as *mut termios::termios);
+    let old_temr = term.clone();
+
+    term.c_iflag &= !(termios::IGNCR | termios::INLCR) as u32;
+    term.c_iflag |= termios::ICRNL as u32;
+    term.c_lflag &= !(termios::ECHO | termios::ISIG) as u32;
+    term.c_lflag |= termios::ICANON as u32;
+
+    termios::tcsetattr(fd, termios::TCSAFLUSH, &term as *const termios::termios);
+    stdio::fputs(prompt, tty);
+    stdio::fflush(tty);
+
+    static mut PASSBUFF: [c_char; PASS_MAX] = [0; PASS_MAX];
+
+    let len = read(fd, PASSBUFF.as_mut_ptr() as *const c_void, PASSBUFF.len());
+
+    if len >= 0 {
+        let mut l = len as usize;
+        if PASSBUFF[l - 1] == b'\n' as c_char || PASSBUFF.len() == l {
+            l -= 1;
+        }
+
+        PASSBUFF[l] = 0;
+    }
+
+    termios::tcsetattr(fd, termios::TCSAFLUSH, &old_temr as *const termios::termios);
+    stdio::fputs(c_str!("\n").as_ptr(), tty);
+    stdio::fclose(tty);
+
+    if len < 0 {
+        return ptr::null_mut();
+    }
+
+    PASSBUFF.as_mut_ptr()
 }
 
 #[no_mangle]