libgo/go/syscall/syscall.go

   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 // Package syscall contains an interface to the low-level operating system
   6 // primitives. The details vary depending on the underlying system, and
   7 // by default, godoc will display the syscall documentation for the current
   8 // system. If you want godoc to display syscall documentation for another
   9 // system, set $GOOS and $GOARCH to the desired system. For example, if
  10 // you want to view documentation for freebsd/arm on linux/amd64, set $GOOS
  11 // to freebsd and $GOARCH to arm.
  12 // The primary use of syscall is inside other packages that provide a more
  13 // portable interface to the system, such as "os", "time" and "net".  Use
  14 // those packages rather than this one if you can.
  15 // For details of the functions and data types in this package consult
  16 // the manuals for the appropriate operating system.
  17 // These calls return err == nil to indicate success; otherwise
  18 // err is an operating system error describing the failure.
  19 // On most systems, that error has type syscall.Errno.
  20 //
  21 // NOTE: This package is locked down. Code outside the standard
  22 // Go repository should be migrated to use the corresponding
  23 // package in the golang.org/x/sys repository. That is also where updates
  24 // required by new systems or versions should be applied.
  25 // Signal, Errno and SysProcAttr are not yet available in
  26 // golang.org/x/sys and must still be referenced from the
  27 // syscall package. See https://golang.org/s/go1.4-syscall
  28 // for more information.
  29 //
  30 package syscall
  31
  32 import "unsafe"
  33
  34 //go:generate go run mksyscall_windows.go -systemdll -output zsyscall_windows.go syscall_windows.go security_windows.go
  35
  36 // StringByteSlice converts a string to a NUL-terminated []byte,
  37 // If s contains a NUL byte this function panics instead of
  38 // returning an error.
  39 //
  40 // Deprecated: Use ByteSliceFromString instead.
  41 func StringByteSlice(s string) []byte {
  42         a, err := ByteSliceFromString(s)
  43         if err != nil {
  44                 panic("syscall: string with NUL passed to StringByteSlice")
  45         }
  46         return a
  47 }
  48
  49 // ByteSliceFromString returns a NUL-terminated slice of bytes
  50 // containing the text of s. If s contains a NUL byte at any
  51 // location, it returns (nil, EINVAL).
  52 func ByteSliceFromString(s string) ([]byte, error) {
  53         for i := 0; i < len(s); i++ {
  54                 if s[i] == 0 {
  55                         return nil, EINVAL
  56                 }
  57         }
  58         a := make([]byte, len(s)+1)
  59         copy(a, s)
  60         return a, nil
  61 }
  62
  63 // StringBytePtr returns a pointer to a NUL-terminated array of bytes.
  64 // If s contains a NUL byte this function panics instead of returning
  65 // an error.
  66 //
  67 // Deprecated: Use BytePtrFromString instead.
  68 func StringBytePtr(s string) *byte { return &StringByteSlice(s)[0] }
  69
  70 // BytePtrFromString returns a pointer to a NUL-terminated array of
  71 // bytes containing the text of s. If s contains a NUL byte at any
  72 // location, it returns (nil, EINVAL).
  73 func BytePtrFromString(s string) (*byte, error) {
  74         a, err := ByteSliceFromString(s)
  75         if err != nil {
  76                 return nil, err
  77         }
  78         return &a[0], nil
  79 }
  80
  81 // Single-word zero for use when we need a valid pointer to 0 bytes.
  82 // See mksyscall.pl.
  83 var _zero uintptr
  84
  85 var dummy *byte
  86
  87 const sizeofPtr uintptr = uintptr(unsafe.Sizeof(dummy))
  88
  89 // Unix returns ts as the number of seconds and nanoseconds elapsed since the
  90 // Unix epoch.
  91 func (ts *Timespec) Unix() (sec int64, nsec int64) {
  92         return int64(ts.Sec), int64(ts.Nsec)
  93 }
  94
  95 // Unix returns tv as the number of seconds and nanoseconds elapsed since the
  96 // Unix epoch.
  97 func (tv *Timeval) Unix() (sec int64, nsec int64) {
  98         return int64(tv.Sec), int64(tv.Usec) * 1000
  99 }
 100
 101 // Nano returns ts as the number of nanoseconds elapsed since the Unix epoch.
 102 func (ts *Timespec) Nano() int64 {
 103         return int64(ts.Sec)*1e9 + int64(ts.Nsec)
 104 }
 105
 106 // Nano returns tv as the number of nanoseconds elapsed since the Unix epoch.
 107 func (tv *Timeval) Nano() int64 {
 108         return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
 109 }
 110
 111 // Getpagesize and Exit are provided by the runtime.
 112
 113 func Getpagesize() int
 114 func Exit(code int)