c_string 0.7.2

C string helpers for Rust
Documentation 
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// Copyright 2014, 2015 Mikhail Zabaluev <mikhail.zabaluev@gmail.com>
// Copyright 2012 The Rust Project Developers
// See the COPYRIGHT file at the top-level directory of this distribution
// and at http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#[macro_use]
extern crate c_string;

extern crate libc;

use std::ffi::CStr;
use std::io::Error as IoError;
use std::io::ErrorKind::InvalidInput;
use std::iter::Iterator;
use std::ptr;

use c_string::{libc_free, parse_c_multistring};
use c_string::{CChars, CStrBuf, OwnedCString};

pub fn check_c_str(c_str: &CStr, expected: &[u8]) {
    let buf = c_str.as_ptr();
    let len = expected.len();
    for i in 0..len {
        let byte = unsafe { *buf.offset(i as isize) as u8 };
        assert_eq!(byte, expected[i]);
    }
    let term = unsafe { *buf.offset(len as isize) as u8 };
    assert_eq!(term, 0);
}

unsafe fn bytes_dup_raw(s: &[u8]) -> *const libc::c_char {
    let len = s.len();
    let dup = libc::malloc((len + 1) as libc::size_t) as *mut u8;
    ptr::copy_nonoverlapping(s.as_ptr(), dup, len);
    *dup.offset(len as isize) = 0;
    dup as *const libc::c_char
}

fn bytes_dup(s: &[u8]) -> OwnedCString {
    unsafe { OwnedCString::new(bytes_dup_raw(s), libc_free) }
}

fn str_dup(s: &str) -> OwnedCString {
    bytes_dup(s.as_bytes())
}

#[test]
fn test_parse_c_multistring() {
    unsafe {
        let input = b"zero\0one\0\0";
        let ptr = input.as_ptr();
        let expected = ["zero", "one"];
        let mut it = expected.iter();
        let result = parse_c_multistring(ptr as *const libc::c_char, None, |cbytes| {
            assert_eq!(cbytes, it.next().unwrap().as_bytes());
        });
        assert_eq!(result, 2);
        assert!(it.next().is_none());
    }
}

#[test]
fn test_c_str_macro() {
    let c_str = c_str!("hello");
    check_c_str(c_str, b"hello");
}

#[test]
fn test_owned_c_string_deref() {
    let c_str = str_dup("hello");
    check_c_str(&c_str, b"hello");
}

#[test]
fn test_owned_c_string_as_ptr() {
    let c_str = str_dup("hello");
    let len = unsafe { libc::strlen(c_str.as_ptr()) };
    assert_eq!(len, 5);
}

#[test]
fn test_iterator() {
    let c_string = str_dup("");
    let mut iter = CChars::from_c_str(&c_string);
    assert_eq!(iter.next(), None);

    let c_string = str_dup("hello");
    let mut iter = CChars::from_c_str(&c_string);
    assert_eq!(iter.next(), Some('h' as libc::c_char));
    assert_eq!(iter.next(), Some('e' as libc::c_char));
    assert_eq!(iter.next(), Some('l' as libc::c_char));
    assert_eq!(iter.next(), Some('l' as libc::c_char));
    assert_eq!(iter.next(), Some('o' as libc::c_char));
    assert_eq!(iter.next(), None);
}

#[test]
fn test_c_str_buf_from_iter() {
    let test_strings: &[&'static [u8]] = &[
        b"",
        b"foo\xFF",
        b"Mary had a little \xD0\x0D, Little \xD0\x0D", // Exercises the owned variant
    ];
    for bytes in test_strings.iter() {
        let c_str = CStrBuf::from_iter(bytes.iter().cloned()).unwrap();
        check_c_str(&c_str, bytes);
    }

    let test_strings: &[&'static [u8]] = &[
        b"got\0nul",
        b"Mary had a little lamb, Little \0", // Exercises the owned variant
    ];
    for bytes in test_strings.iter() {
        let res = CStrBuf::from_iter(bytes.iter().cloned());
        let err = res.err().unwrap();
        assert_eq!(
            err.nul_position(),
            bytes.iter().position(|b| *b == 0u8).unwrap()
        );
        let vec = err.into_bytes();
        assert_eq!(&vec, bytes);
    }
}

#[test]
fn test_c_str_buf_from_str() {
    let c_str = CStrBuf::from_str("").unwrap();
    check_c_str(&c_str, b"");

    let c_str = CStrBuf::from_str("hello").unwrap();
    check_c_str(&c_str, b"hello");

    // Owned variant
    let c_str = CStrBuf::from_str("Mary had a little lamb, Little lamb").unwrap();
    check_c_str(&c_str, b"Mary had a little lamb, Little lamb");

    let res = CStrBuf::from_str("got\0nul");
    let err = res.err().unwrap();
    assert_eq!(err.nul_position(), 3);
    let bytes = err.into_bytes();
    assert_eq!(bytes, b"got\0nul");
}

#[test]
fn test_io_error_from_nul_error() {
    let res = CStrBuf::from_str("got\0nul");
    let err = res.err().unwrap();
    let io_err = IoError::from(err);
    assert_eq!(io_err.kind(), InvalidInput);
}

#[test]
fn test_c_str_buf_from_vec() {
    let test_strings: &[&'static [u8]] = &[
        b"",
        b"foo\xFF",
        b"Mary had a little \xD0\x0D, Little \xD0\x0D", // Exercises the owned variant
    ];
    for bytes in test_strings.iter() {
        let c_str = CStrBuf::from_vec(bytes.to_vec()).unwrap();
        check_c_str(&c_str, bytes);
    }

    let test_strings: &[&'static [u8]] = &[
        b"got\0nul",
        b"Mary had a little lamb, Little \0", // Exercises the owned variant
    ];
    for bytes in test_strings.iter() {
        let res = CStrBuf::from_vec(bytes.to_vec());
        let err = res.err().unwrap();
        assert_eq!(
            err.nul_position(),
            bytes.iter().position(|b| *b == 0u8).unwrap()
        );
        let vec = err.into_bytes();
        assert_eq!(&vec, bytes);
    }
}

#[test]
fn test_io_error_from_into_c_str_error() {
    let res = CStrBuf::from_vec(b"got\0nul".to_vec());
    let err = res.err().unwrap();
    let io_err = IoError::from(err);
    assert_eq!(io_err.kind(), InvalidInput);
}

#[test]
fn test_c_str_buf_into_vec() {
    let c_str = CStrBuf::from_str("").unwrap();
    let vec = c_str.into_vec();
    assert_eq!(&vec[..], b"");
    let c_str = CStrBuf::from_str("hello").unwrap();
    let vec = c_str.into_vec();
    assert_eq!(&vec[..], b"hello");
    let bytes = b"foo\xFF";
    let c_str = CStrBuf::from_iter(bytes.iter().cloned()).unwrap();
    let vec = c_str.into_vec();
    assert_eq!(&vec[..], bytes);

    // Owned variant
    let c_str = CStrBuf::from_str("Mary had a little lamb, Little lamb").unwrap();
    let vec = c_str.into_vec();
    assert_eq!(&vec[..], &b"Mary had a little lamb, Little lamb"[..]);
    let bytes = b"Mary had a little \xD0\x0D, Little \xD0\x0D";
    let c_str = CStrBuf::from_iter(bytes.iter().cloned()).unwrap();
    let vec = c_str.into_vec();
    assert_eq!(&vec[..], bytes);
}

#[test]
fn test_owned_c_string_to_bytes() {
    let c_str = str_dup("hello");
    assert_eq!(c_str.to_bytes(), b"hello");
    let c_str = str_dup("");
    assert_eq!(c_str.to_bytes(), b"");
    let c_str = bytes_dup(b"foo\xFF");
    assert_eq!(c_str.to_bytes(), b"foo\xFF");
}

#[test]
fn test_owned_c_string_debug() {
    let c_str = str_dup("hello");
    let msg = format!("{:?}", c_str);
    assert_eq!(msg, "\"hello\"");
    let c_str = str_dup("");
    let msg = format!("{:?}", c_str);
    assert_eq!(msg, "\"\"");
    let c_str = bytes_dup(b"foo\xFF");
    let msg = format!("{:?}", c_str);
    assert_eq!(msg, r#""foo\xff""#);
}

#[test]
#[should_panic]
fn test_c_string_new_fail() {
    let _c_str: OwnedCString = unsafe { OwnedCString::new(ptr::null(), libc_free) };
}