github.com/aayushi-bansal/sys@v0.0.0-20180118120756-90d962a959d8/unix/syscall.go (about) 1 // Copyright 2009 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // +build darwin dragonfly freebsd linux netbsd openbsd solaris 6 7 // Package unix contains an interface to the low-level operating system 8 // primitives. OS details vary depending on the underlying system, and 9 // by default, godoc will display OS-specific documentation for the current 10 // system. If you want godoc to display OS documentation for another 11 // system, set $GOOS and $GOARCH to the desired system. For example, if 12 // you want to view documentation for freebsd/arm on linux/amd64, set $GOOS 13 // to freebsd and $GOARCH to arm. 14 // The primary use of this package is inside other packages that provide a more 15 // portable interface to the system, such as "os", "time" and "net". Use 16 // those packages rather than this one if you can. 17 // For details of the functions and data types in this package consult 18 // the manuals for the appropriate operating system. 19 // These calls return err == nil to indicate success; otherwise 20 // err represents an operating system error describing the failure and 21 // holds a value of type syscall.Errno. 22 package unix // import "golang.org/x/sys/unix" 23 24 // ByteSliceFromString returns a NUL-terminated slice of bytes 25 // containing the text of s. If s contains a NUL byte at any 26 // location, it returns (nil, EINVAL). 27 func ByteSliceFromString(s string) ([]byte, error) { 28 for i := 0; i < len(s); i++ { 29 if s[i] == 0 { 30 return nil, EINVAL 31 } 32 } 33 a := make([]byte, len(s)+1) 34 copy(a, s) 35 return a, nil 36 } 37 38 // BytePtrFromString returns a pointer to a NUL-terminated array of 39 // bytes containing the text of s. If s contains a NUL byte at any 40 // location, it returns (nil, EINVAL). 41 func BytePtrFromString(s string) (*byte, error) { 42 a, err := ByteSliceFromString(s) 43 if err != nil { 44 return nil, err 45 } 46 return &a[0], nil 47 } 48 49 // Single-word zero for use when we need a valid pointer to 0 bytes. 50 // See mkunix.pl. 51 var _zero uintptr