gtsocial-umbx

syscall.go (2954B)

---

 // 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.
 
 //go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
 // +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
 
 // 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"
 )
 
 // 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)
 	}
 
 	return string(unsafe.Slice(p, n))
 }
 
 // Single-word zero for use when we need a valid pointer to 0 bytes.
 var _zero uintptr