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rust/src/libstd/sys/unix/memchr.rs
2017-12-13 01:15:18 -06:00

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1.7 KiB
Rust

// Copyright 2015 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.
//
// Original implementation taken from rust-memchr
// Copyright 2015 Andrew Gallant, bluss and Nicolas Koch
pub fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> {
use libc;
let p = unsafe {
libc::memchr(
haystack.as_ptr() as *const libc::c_void,
needle as libc::c_int,
haystack.len())
};
if p.is_null() {
None
} else {
Some(p as usize - (haystack.as_ptr() as usize))
}
}
pub fn memrchr(needle: u8, haystack: &[u8]) -> Option<usize> {
#[cfg(target_os = "linux")]
fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> {
use libc;
// GNU's memrchr() will - unlike memchr() - error if haystack is empty.
if haystack.is_empty() {return None}
let p = unsafe {
libc::memrchr(
haystack.as_ptr() as *const libc::c_void,
needle as libc::c_int,
haystack.len())
};
if p.is_null() {
None
} else {
Some(p as usize - (haystack.as_ptr() as usize))
}
}
#[cfg(not(target_os = "linux"))]
fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> {
::core::slice::memchr::memrchr(needle, haystack)
}
memrchr_specific(needle, haystack)
}