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 //go:build windows
6 7 // Package windows 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 the OS-specific documentation for the current
10 // system. If you want godoc to display syscall 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 //
15 // The primary use of this package is inside other packages that provide a more
16 // portable interface to the system, such as "os", "time" and "net". Use
17 // those packages rather than this one if you can.
18 //
19 // For details of the functions and data types in this package consult
20 // the manuals for the appropriate operating system.
21 //
22 // These calls return err == nil to indicate success; otherwise
23 // err represents an operating system error describing the failure and
24 // holds a value of type syscall.Errno.
25 package windows // import "golang.org/x/sys/windows"
26 27 import (
28 "bytes"
29 "strings"
30 "syscall"
31 "unsafe"
32 )
33 34 // ByteSliceFromString returns a NUL-terminated slice of bytes
35 // containing the text of s. If s contains a NUL byte at any
36 // location, it returns (nil, syscall.EINVAL).
37 func ByteSliceFromString(s string) ([]byte, error) {
38 if strings.IndexByte(s, 0) != -1 {
39 return nil, syscall.EINVAL
40 }
41 a := make([]byte, len(s)+1)
42 copy(a, s)
43 return a, nil
44 }
45 46 // BytePtrFromString returns a pointer to a NUL-terminated array of
47 // bytes containing the text of s. If s contains a NUL byte at any
48 // location, it returns (nil, syscall.EINVAL).
49 func BytePtrFromString(s string) (*byte, error) {
50 a, err := ByteSliceFromString(s)
51 if err != nil {
52 return nil, err
53 }
54 return &a[0], nil
55 }
56 57 // ByteSliceToString returns a string form of the text represented by the slice s, with a terminating NUL and any
58 // bytes after the NUL removed.
59 func ByteSliceToString(s []byte) string {
60 if i := bytes.IndexByte(s, 0); i != -1 {
61 s = s[:i]
62 }
63 return string(s)
64 }
65 66 // BytePtrToString takes a pointer to a sequence of text and returns the corresponding string.
67 // If the pointer is nil, it returns the empty string. It assumes that the text sequence is terminated
68 // at a zero byte; if the zero byte is not present, the program may crash.
69 func BytePtrToString(p *byte) string {
70 if p == nil {
71 return ""
72 }
73 if *p == 0 {
74 return ""
75 }
76 77 // Find NUL terminator.
78 n := 0
79 for ptr := unsafe.Pointer(p); *(*byte)(ptr) != 0; n++ {
80 ptr = unsafe.Pointer(uintptr(ptr) + 1)
81 }
82 83 return string(unsafe.Slice(p, n))
84 }
85 86 // Single-word zero for use when we need a valid pointer to 0 bytes.
87 // See mksyscall.pl.
88 var _zero uintptr
89 90 func (ts *Timespec) Unix() (sec int64, nsec int64) {
91 return int64(ts.Sec), int64(ts.Nsec)
92 }
93 94 func (tv *Timeval) Unix() (sec int64, nsec int64) {
95 return int64(tv.Sec), int64(tv.Usec) * 1000
96 }
97 98 func (ts *Timespec) Nano() int64 {
99 return int64(ts.Sec)*1e9 + int64(ts.Nsec)
100 }
101 102 func (tv *Timeval) Nano() int64 {
103 return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
104 }
105