Merge pull request #1189 from ProgVal/unlink-nul-terminator

unlink: Add a nul-terminator after the file name before calling lstat.

src/unlink/unlink.rs

@@ -19,9 +19,10 @@ extern crate uucore;
 
 use getopts::Options;
 use libc::{S_IFLNK, S_IFMT, S_IFREG};
-use libc::{c_char, lstat, stat, unlink};
+use libc::{lstat, stat, unlink};
 use std::io::{Error, ErrorKind};
 use std::mem::uninitialized;
+use std::ffi::CString;
 
 static NAME: &'static str = "unlink";
 static VERSION: &'static str = env!("CARGO_PKG_VERSION");
@@ -67,11 +68,13 @@ pub fn uumain(args: Vec<String>) -> i32 {
         );
     }
 
+    let c_string = CString::new(matches.free[0].clone()).unwrap(); // unwrap() cannot fail, the string comes from argv so it cannot contain a \0.
+
     let st_mode = {
         let mut buf: stat = unsafe { uninitialized() };
         let result = unsafe {
             lstat(
-                matches.free[0].as_ptr() as *const c_char,
+                c_string.as_ptr(),
                 &mut buf as *mut stat,
             )
         };
@@ -94,7 +97,7 @@ pub fn uumain(args: Vec<String>) -> i32 {
             "Not a regular file or symlink",
         ))
     } else {
-        let result = unsafe { unlink(matches.free[0].as_ptr() as *const c_char) };
+        let result = unsafe { unlink(c_string.as_ptr()) };
 
         if result < 0 {
             Err(Error::last_os_error())