mirror of
https://github.com/golang/sys.git
synced 2026-02-08 11:46:04 +03:00
6e5568b54d
We already provide ByteSliceFromString and BytePtrFromString, and on Windows we provide UTF16FromString, UTF16PtrFromString, UTF16ToString, and UTF16PtrToString. So this commit fills in the remaining two Byte-oriented functions: ByteSliceToString and BytePtrToString. Since the existing two are available on windows, unix, and plan9, we add the remaining two to the same places. This helps eliminate unsafe pointer options in addition to triggering checkptr in Go 1.15, by eliminating the use of prior idioms for these types of casts. Change-Id: I85ae49f2756e142c2462fe8b2428216b6992e089 Reviewed-on: https://go-review.googlesource.com/c/sys/+/263757 Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Trust: Brad Fitzpatrick <bradfitz@golang.org> Trust: Jason A. Donenfeld <Jason@zx2c4.com>
95 lines
2.9 KiB
Go
95 lines
2.9 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
|
|
|
|
// Package unix contains an interface to the low-level operating system
|
|
// primitives. OS details vary depending on the underlying system, and
|
|
// by default, godoc will display OS-specific documentation for the current
|
|
// system. If you want godoc to display OS documentation for another
|
|
// system, set $GOOS and $GOARCH to the desired system. For example, if
|
|
// you want to view documentation for freebsd/arm on linux/amd64, set $GOOS
|
|
// to freebsd and $GOARCH to arm.
|
|
//
|
|
// The primary use of this package is inside other packages that provide a more
|
|
// portable interface to the system, such as "os", "time" and "net". Use
|
|
// those packages rather than this one if you can.
|
|
//
|
|
// For details of the functions and data types in this package consult
|
|
// the manuals for the appropriate operating system.
|
|
//
|
|
// These calls return err == nil to indicate success; otherwise
|
|
// err represents an operating system error describing the failure and
|
|
// holds a value of type syscall.Errno.
|
|
package unix // import "golang.org/x/sys/unix"
|
|
|
|
import (
|
|
"bytes"
|
|
"strings"
|
|
"unsafe"
|
|
|
|
"golang.org/x/sys/internal/unsafeheader"
|
|
)
|
|
|
|
// ByteSliceFromString returns a NUL-terminated slice of bytes
|
|
// containing the text of s. If s contains a NUL byte at any
|
|
// location, it returns (nil, EINVAL).
|
|
func ByteSliceFromString(s string) ([]byte, error) {
|
|
if strings.IndexByte(s, 0) != -1 {
|
|
return nil, EINVAL
|
|
}
|
|
a := make([]byte, len(s)+1)
|
|
copy(a, s)
|
|
return a, nil
|
|
}
|
|
|
|
// BytePtrFromString returns a pointer to a NUL-terminated array of
|
|
// bytes containing the text of s. If s contains a NUL byte at any
|
|
// location, it returns (nil, EINVAL).
|
|
func BytePtrFromString(s string) (*byte, error) {
|
|
a, err := ByteSliceFromString(s)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &a[0], nil
|
|
}
|
|
|
|
// ByteSliceToString returns a string form of the text represented by the slice s, with a terminating NUL and any
|
|
// bytes after the NUL removed.
|
|
func ByteSliceToString(s []byte) string {
|
|
if i := bytes.IndexByte(s, 0); i != -1 {
|
|
s = s[:i]
|
|
}
|
|
return string(s)
|
|
}
|
|
|
|
// BytePtrToString takes a pointer to a sequence of text and returns the corresponding string.
|
|
// If the pointer is nil, it returns the empty string. It assumes that the text sequence is terminated
|
|
// at a zero byte; if the zero byte is not present, the program may crash.
|
|
func BytePtrToString(p *byte) string {
|
|
if p == nil {
|
|
return ""
|
|
}
|
|
if *p == 0 {
|
|
return ""
|
|
}
|
|
|
|
// Find NUL terminator.
|
|
n := 0
|
|
for ptr := unsafe.Pointer(p); *(*byte)(ptr) != 0; n++ {
|
|
ptr = unsafe.Pointer(uintptr(ptr) + 1)
|
|
}
|
|
|
|
var s []byte
|
|
h := (*unsafeheader.Slice)(unsafe.Pointer(&s))
|
|
h.Data = unsafe.Pointer(p)
|
|
h.Len = n
|
|
h.Cap = n
|
|
|
|
return string(s)
|
|
}
|
|
|
|
// Single-word zero for use when we need a valid pointer to 0 bytes.
|
|
var _zero uintptr
|