github.com/aayushi-bansal/sys@v0.0.0-20180118120756-90d962a959d8/unix/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 darwin dragonfly freebsd linux netbsd openbsd solaris
     6  
     7  // Package unix 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 OS-specific documentation for the current
    10  // system. If you want godoc to display OS 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  // The primary use of this package is inside other packages that provide a more
    15  // portable interface to the system, such as "os", "time" and "net".  Use
    16  // those packages rather than this one if you can.
    17  // For details of the functions and data types in this package consult
    18  // the manuals for the appropriate operating system.
    19  // These calls return err == nil to indicate success; otherwise
    20  // err represents an operating system error describing the failure and
    21  // holds a value of type syscall.Errno.
    22  package unix // import "golang.org/x/sys/unix"
    23  
    24  // ByteSliceFromString returns a NUL-terminated slice of bytes
    25  // containing the text of s. If s contains a NUL byte at any
    26  // location, it returns (nil, EINVAL).
    27  func ByteSliceFromString(s string) ([]byte, error) {
    28  	for i := 0; i < len(s); i++ {
    29  		if s[i] == 0 {
    30  			return nil, EINVAL
    31  		}
    32  	}
    33  	a := make([]byte, len(s)+1)
    34  	copy(a, s)
    35  	return a, nil
    36  }
    37  
    38  // BytePtrFromString returns a pointer to a NUL-terminated array of
    39  // bytes containing the text of s. If s contains a NUL byte at any
    40  // location, it returns (nil, EINVAL).
    41  func BytePtrFromString(s string) (*byte, error) {
    42  	a, err := ByteSliceFromString(s)
    43  	if err != nil {
    44  		return nil, err
    45  	}
    46  	return &a[0], nil
    47  }
    48  
    49  // Single-word zero for use when we need a valid pointer to 0 bytes.
    50  // See mkunix.pl.
    51  var _zero uintptr