github.com/dannin/go@v0.0.0-20161031215817-d35dfd405eaa/src/syscall/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  // 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  // See https://golang.org/s/go1.4-syscall for more information.
    26  //
    27  package syscall
    28  
    29  import "unsafe"
    30  
    31  //go:generate go run mksyscall_windows.go -systemdll -output zsyscall_windows.go syscall_windows.go security_windows.go
    32  
    33  // StringByteSlice converts a string to a NUL-terminated []byte,
    34  // If s contains a NUL byte this function panics instead of
    35  // returning an error.
    36  //
    37  // Deprecated: Use ByteSliceFromString instead.
    38  func StringByteSlice(s string) []byte {
    39  	a, err := ByteSliceFromString(s)
    40  	if err != nil {
    41  		panic("syscall: string with NUL passed to StringByteSlice")
    42  	}
    43  	return a
    44  }
    45  
    46  // ByteSliceFromString returns a NUL-terminated slice of bytes
    47  // containing the text of s. If s contains a NUL byte at any
    48  // location, it returns (nil, EINVAL).
    49  func ByteSliceFromString(s string) ([]byte, error) {
    50  	for i := 0; i < len(s); i++ {
    51  		if s[i] == 0 {
    52  			return nil, EINVAL
    53  		}
    54  	}
    55  	a := make([]byte, len(s)+1)
    56  	copy(a, s)
    57  	return a, nil
    58  }
    59  
    60  // StringBytePtr returns a pointer to a NUL-terminated array of bytes.
    61  // If s contains a NUL byte this function panics instead of returning
    62  // an error.
    63  //
    64  // Deprecated: Use BytePtrFromString instead.
    65  func StringBytePtr(s string) *byte { return &StringByteSlice(s)[0] }
    66  
    67  // BytePtrFromString returns a pointer to a NUL-terminated array of
    68  // bytes containing the text of s. If s contains a NUL byte at any
    69  // location, it returns (nil, EINVAL).
    70  func BytePtrFromString(s string) (*byte, error) {
    71  	a, err := ByteSliceFromString(s)
    72  	if err != nil {
    73  		return nil, err
    74  	}
    75  	return &a[0], nil
    76  }
    77  
    78  // Single-word zero for use when we need a valid pointer to 0 bytes.
    79  // See mksyscall.pl.
    80  var _zero uintptr
    81  
    82  func (ts *Timespec) Unix() (sec int64, nsec int64) {
    83  	return int64(ts.Sec), int64(ts.Nsec)
    84  }
    85  
    86  func (tv *Timeval) Unix() (sec int64, nsec int64) {
    87  	return int64(tv.Sec), int64(tv.Usec) * 1000
    88  }
    89  
    90  func (ts *Timespec) Nano() int64 {
    91  	return int64(ts.Sec)*1e9 + int64(ts.Nsec)
    92  }
    93  
    94  func (tv *Timeval) Nano() int64 {
    95  	return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
    96  }
    97  
    98  // Getpagesize is provided by the runtime.
    99  
   100  func Getpagesize() int
   101  
   102  // use is a no-op, but the compiler cannot see that it is.
   103  // Calling use(p) ensures that p is kept live until that point.
   104  // This was needed until Go 1.6 to call syscall.Syscall correctly.
   105  // As of Go 1.6 the compiler handles that case automatically.
   106  // The uses and definition of use can be removed early in the Go 1.7 cycle.
   107  //go:noescape
   108  func use(p unsafe.Pointer)