env_windows.go

     1  // Copyright 2010 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  // Windows environment variables.
     6  
     7  package windows
     8  
     9  import (
    10  	"syscall"
    11  	"unsafe"
    12  )
    13  
    14  func Getenv(key string) (value string, found bool) {
    15  	return syscall.Getenv(key)
    16  }
    17  
    18  func Setenv(key, value string) error {
    19  	return syscall.Setenv(key, value)
    20  }
    21  
    22  func Clearenv() {
    23  	syscall.Clearenv()
    24  }
    25  
    26  func Environ() []string {
    27  	return syscall.Environ()
    28  }
    29  
    30  // Returns a default environment associated with the token, rather than the current
    31  // process. If inheritExisting is true, then this environment also inherits the
    32  // environment of the current process.
    33  func (token Token) Environ(inheritExisting bool) (env []string, err error) {
    34  	var block *uint16
    35  	err = CreateEnvironmentBlock(&block, token, inheritExisting)
    36  	if err != nil {
    37  		return nil, err
    38  	}
    39  	defer DestroyEnvironmentBlock(block)
    40  	size := unsafe.Sizeof(*block)
    41  	for *block != 0 {
    42  		// find NUL terminator
    43  		end := unsafe.Pointer(block)
    44  		for *(*uint16)(end) != 0 {
    45  			end = unsafe.Add(end, size)
    46  		}
    47  
    48  		entry := unsafe.Slice(block, (uintptr(end)-uintptr(unsafe.Pointer(block)))/size)
    49  		env = append(env, UTF16ToString(entry))
    50  		block = (*uint16)(unsafe.Add(end, size))
    51  	}
    52  	return env, nil
    53  }
    54  
    55  func Unsetenv(key string) error {
    56  	return syscall.Unsetenv(key)
    57  }
    58
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