github.com/Andyfoo/golang/x/sys@v0.0.0-20190901054642-57c1bf301704/plan9/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 plan9
     6  
     7  // Package plan9 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 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.ErrorString.
    25  package plan9 // import "github.com/Andyfoo/golang/x/sys/plan9"
    26  
    27  import "unsafe"
    28  
    29  // ByteSliceFromString returns a NUL-terminated slice of bytes
    30  // containing the text of s. If s contains a NUL byte at any
    31  // location, it returns (nil, EINVAL).
    32  func ByteSliceFromString(s string) ([]byte, error) {
    33  	for i := 0; i < len(s); i++ {
    34  		if s[i] == 0 {
    35  			return nil, EINVAL
    36  		}
    37  	}
    38  	a := make([]byte, len(s)+1)
    39  	copy(a, s)
    40  	return a, nil
    41  }
    42  
    43  // BytePtrFromString returns a pointer to a NUL-terminated array of
    44  // bytes containing the text of s. If s contains a NUL byte at any
    45  // location, it returns (nil, EINVAL).
    46  func BytePtrFromString(s string) (*byte, error) {
    47  	a, err := ByteSliceFromString(s)
    48  	if err != nil {
    49  		return nil, err
    50  	}
    51  	return &a[0], nil
    52  }
    53  
    54  // Single-word zero for use when we need a valid pointer to 0 bytes.
    55  // See mksyscall.pl.
    56  var _zero uintptr
    57  
    58  func (ts *Timespec) Unix() (sec int64, nsec int64) {
    59  	return int64(ts.Sec), int64(ts.Nsec)
    60  }
    61  
    62  func (tv *Timeval) Unix() (sec int64, nsec int64) {
    63  	return int64(tv.Sec), int64(tv.Usec) * 1000
    64  }
    65  
    66  func (ts *Timespec) Nano() int64 {
    67  	return int64(ts.Sec)*1e9 + int64(ts.Nsec)
    68  }
    69  
    70  func (tv *Timeval) Nano() int64 {
    71  	return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
    72  }
    73  
    74  // use is a no-op, but the compiler cannot see that it is.
    75  // Calling use(p) ensures that p is kept live until that point.
    76  //go:noescape
    77  func use(p unsafe.Pointer)