golang syscall 代码
文件路径：/src/cmd/vendor/golang.org/x/sys/plan9/syscall.go
/ Copyright 2009 The Go Authors. All rights reserved.
/ Use of this source code is governed by a BSD-style
/ license that can be found in the LICENSE file.
/go:build plan9
/ +build plan9
/ Package plan9 contains an interface to the low-level operating system
/ primitives. OS details vary depending on the underlying system, and
/ by default, godoc will display the OS-specific documentation for the current
/ system. If you want godoc to display documentation for another
/ system, set $GOOS and $GOARCH to the desired system. For example, if
/ you want to view documentation for freebsd/arm on linux/amd64, set $GOOS
/ to freebsd and $GOARCH to arm.
/
/ The primary use of this package is inside other packages that provide a more
/ portable interface to the system, such as "os", "time" and "net". Use
/ those packages rather than this one if you can.
/
/ For details of the functions and data types in this package consult
/ the manuals for the appropriate operating system.
/
/ These calls return err == nil to indicate success; otherwise
/ err represents an operating system error describing the failure and
/ holds a value of type syscall.ErrorString.
package plan9 / import "golang.org/x/sys/plan9"
import (
"bytes"
"strings"
"unsafe"
"golang.org/x/sys/internal/unsafeheader"
)
/ ByteSliceFromString returns a NUL-terminated slice of bytes
/ containing the text of s. If s contains a NUL byte at any
/ location, it returns (nil, EINVAL).
func ByteSliceFromString(s string) ([]byte, error) {
if strings.IndexByte(s, 0) != -1 {
return nil, EINVAL
}
a := make([]byte, len(s)+1)
copy(a, s)
return a, nil
}
/ BytePtrFromString returns a pointer to a NUL-terminated array of
/ bytes containing the text of s. If s contains a NUL byte at any
/ location, it returns (nil, EINVAL).
func BytePtrFromString(s string) (*byte, error) {
a, err := ByteSliceFromString(s)
if err != nil {
return nil, err
}
return &a[0], nil
}
/ ByteSliceToString returns a string form of the text represented by the slice s, with a terminating NUL and any
/ bytes after the NUL removed.
func ByteSliceToString(s []byte) string {
if i := bytes.IndexByte(s, 0); i != -1 {
s = s[:i]
}
return string(s)
}
/ BytePtrToString takes a pointer to a sequence of text and returns the corresponding string.
/ If the pointer is nil, it returns the empty string. It assumes that the text sequence is terminated
/ at a zero byte; if the zero byte is not present, the program may crash.
func BytePtrToString(p *byte) string {
if p == nil {
return ""
}
if *p == 0 {
return ""
}
/ Find NUL terminator.
n := 0
for ptr := unsafe.Pointer(p); *(*byte)(ptr) != 0; n++ {
ptr = unsafe.Pointer(uintptr(ptr) + 1)
}
var s []byte
h := (*unsafeheader.Slice)(unsafe.Pointer(&s))
h.Data = unsafe.Pointer(p)
h.Len = n
h.Cap = n
return string(s)
}
/ Single-word zero for use when we need a valid pointer to 0 bytes.
/ See mksyscall.pl.
var _zero uintptr
func (ts *Timespec) Unix() (sec int64, nsec int64) {
return int64(ts.Sec), int64(ts.Nsec)
}
func (tv *Timeval) Unix() (sec int64, nsec int64) {
return int64(tv.Sec), int64(tv.Usec) * 1000
}
func (ts *Timespec) Nano() int64 {
return int64(ts.Sec)*1e9 + int64(ts.Nsec)
}
func (tv *Timeval) Nano() int64 {
return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
}
/ use is a no-op, but the compiler cannot see that it is.
/ Calling use(p) ensures that p is kept live until that point.
/
/go:noescape
func use(p unsafe.Pointer)