text: // 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 "strings"
  
  // 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
  }
  
  // Single-word zero for use when we need a valid pointer to 0 bytes.
  // See mkunix.pl.
  var _zero uintptr
  