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 [Errno].
    20  //
    21  // NOTE: Most of the functions, types, and constants defined in
    22  // this package are also available in the [golang.org/x/sys] package.
    23  // That package has more system call support than this one,
    24  // and most new code should prefer that package where possible.
    25  // See https://golang.org/s/go1.4-syscall for more information.
    26  package syscall
    27  
    28  import "internal/bytealg"
    29  
    30  //go:generate go run ./mksyscall_windows.go -systemdll -output zsyscall_windows.go syscall_windows.go security_windows.go
    31  
    32  // StringByteSlice converts a string to a NUL-terminated []byte,
    33  // If s contains a NUL byte this function panics instead of
    34  // returning an error.
    35  //
    36  // Deprecated: Use ByteSliceFromString instead.
    37  func StringByteSlice(s string) []byte {
    38  	a, err := ByteSliceFromString(s)
    39  	if err != nil {
    40  		panic("syscall: string with NUL passed to StringByteSlice")
    41  	}
    42  	return a
    43  }
    44  
    45  // ByteSliceFromString returns a NUL-terminated slice of bytes
    46  // containing the text of s. If s contains a NUL byte at any
    47  // location, it returns (nil, [EINVAL]).
    48  func ByteSliceFromString(s string) ([]byte, error) {
    49  	if bytealg.IndexByteString(s, 0) != -1 {
    50  		return nil, EINVAL
    51  	}
    52  	a := make([]byte, len(s)+1)
    53  	copy(a, s)
    54  	return a, nil
    55  }
    56  
    57  // StringBytePtr returns a pointer to a NUL-terminated array of bytes.
    58  // If s contains a NUL byte this function panics instead of returning
    59  // an error.
    60  //
    61  // Deprecated: Use [BytePtrFromString] instead.
    62  func StringBytePtr(s string) *byte { return &StringByteSlice(s)[0] }
    63  
    64  // BytePtrFromString returns a pointer to a NUL-terminated array of
    65  // bytes containing the text of s. If s contains a NUL byte at any
    66  // location, it returns (nil, [EINVAL]).
    67  func BytePtrFromString(s string) (*byte, error) {
    68  	a, err := ByteSliceFromString(s)
    69  	if err != nil {
    70  		return nil, err
    71  	}
    72  	return &a[0], nil
    73  }
    74  
    75  // Single-word zero for use when we need a valid pointer to 0 bytes.
    76  // See mksyscall.pl.
    77  var _zero uintptr
    78  
    79  // Unix returns the time stored in ts as seconds plus nanoseconds.
    80  func (ts *Timespec) Unix() (sec int64, nsec int64) {
    81  	return int64(ts.Sec), int64(ts.Nsec)
    82  }
    83  
    84  // Unix returns the time stored in tv as seconds plus nanoseconds.
    85  func (tv *Timeval) Unix() (sec int64, nsec int64) {
    86  	return int64(tv.Sec), int64(tv.Usec) * 1000
    87  }
    88  
    89  // Nano returns the time stored in ts as nanoseconds.
    90  func (ts *Timespec) Nano() int64 {
    91  	return int64(ts.Sec)*1e9 + int64(ts.Nsec)
    92  }
    93  
    94  // Nano returns the time stored in tv as nanoseconds.
    95  func (tv *Timeval) Nano() int64 {
    96  	return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
    97  }
    98  
    99  // Getpagesize and Exit are provided by the runtime.
   100  
   101  func Getpagesize() int
   102  func Exit(code int)
   103  
   104  // runtimeSetenv and runtimeUnsetenv are provided by the runtime.
   105  func runtimeSetenv(k, v string)
   106  func runtimeUnsetenv(k string)
   107
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