1
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
2
// Use of this source code is governed by a BSD-style license that can be
3
// found in the LICENSE file.
5
#ifndef BASE_ENVIRONMENT_H_
6
#define BASE_ENVIRONMENT_H_
11
#include "base/base_export.h"
12
#include "base/memory/scoped_ptr.h"
13
#include "base/strings/string16.h"
14
#include "build/build_config.h"
21
BASE_EXPORT extern const char kHome[];
24
} // namespace env_vars
26
class BASE_EXPORT Environment {
28
virtual ~Environment();
30
// Static factory method that returns the implementation that provide the
31
// appropriate platform-specific instance.
32
static Environment* Create();
34
// Gets an environment variable's value and stores it in |result|.
35
// Returns false if the key is unset.
36
virtual bool GetVar(const char* variable_name, std::string* result) = 0;
38
// Syntactic sugar for GetVar(variable_name, NULL);
39
virtual bool HasVar(const char* variable_name);
41
// Returns true on success, otherwise returns false.
42
virtual bool SetVar(const char* variable_name,
43
const std::string& new_value) = 0;
45
// Returns true on success, otherwise returns false.
46
virtual bool UnSetVar(const char* variable_name) = 0;
52
typedef string16 NativeEnvironmentString;
53
typedef std::map<NativeEnvironmentString, NativeEnvironmentString>
56
// Returns a modified environment vector constructed from the given environment
57
// and the list of changes given in |changes|. Each key in the environment is
58
// matched against the first element of the pairs. In the event of a match, the
59
// value is replaced by the second of the pair, unless the second is empty, in
60
// which case the key-value is removed.
62
// This Windows version takes and returns a Windows-style environment block
63
// which is a concatenated list of null-terminated 16-bit strings. The end is
64
// marked by a double-null terminator. The size of the returned string will
65
// include the terminators.
66
BASE_EXPORT string16 AlterEnvironment(const wchar_t* env,
67
const EnvironmentMap& changes);
69
#elif defined(OS_POSIX)
71
typedef std::string NativeEnvironmentString;
72
typedef std::map<NativeEnvironmentString, NativeEnvironmentString>
75
// See general comments for the Windows version above.
77
// This Posix version takes and returns a Posix-style environment block, which
78
// is a null-terminated list of pointers to null-terminated strings. The
79
// returned array will have appended to it the storage for the array itself so
80
// there is only one pointer to manage, but this means that you can't copy the
81
// array without keeping the original around.
82
BASE_EXPORT scoped_ptr<char*[]> AlterEnvironment(
83
const char* const* env,
84
const EnvironmentMap& changes);
90
#endif // BASE_ENVIRONMENT_H_