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1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. |
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2 // Use of this source code is governed by a BSD-style license that can be |
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3 // found in the LICENSE file. |
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4 |
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5 #ifndef BASE_ENVIRONMENT_H_ |
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6 #define BASE_ENVIRONMENT_H_ |
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7 |
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8 #include <map> |
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9 #include <string> |
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10 |
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11 #include "base/base_export.h" |
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12 #include "base/memory/scoped_ptr.h" |
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13 #include "base/strings/string16.h" |
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14 #include "build/build_config.h" |
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15 |
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16 namespace base { |
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17 |
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18 namespace env_vars { |
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19 |
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20 #if defined(OS_POSIX) |
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21 BASE_EXPORT extern const char kHome[]; |
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22 #endif |
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23 |
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24 } // namespace env_vars |
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25 |
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26 class BASE_EXPORT Environment { |
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27 public: |
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28 virtual ~Environment(); |
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29 |
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30 // Static factory method that returns the implementation that provide the |
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31 // appropriate platform-specific instance. |
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32 static Environment* Create(); |
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33 |
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34 // Gets an environment variable's value and stores it in |result|. |
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35 // Returns false if the key is unset. |
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36 virtual bool GetVar(const char* variable_name, std::string* result) = 0; |
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37 |
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38 // Syntactic sugar for GetVar(variable_name, NULL); |
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39 virtual bool HasVar(const char* variable_name); |
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40 |
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41 // Returns true on success, otherwise returns false. |
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42 virtual bool SetVar(const char* variable_name, |
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43 const std::string& new_value) = 0; |
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44 |
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45 // Returns true on success, otherwise returns false. |
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46 virtual bool UnSetVar(const char* variable_name) = 0; |
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47 }; |
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48 |
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49 |
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50 #if defined(OS_WIN) |
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51 |
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52 typedef string16 NativeEnvironmentString; |
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53 typedef std::map<NativeEnvironmentString, NativeEnvironmentString> |
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54 EnvironmentMap; |
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55 |
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56 // Returns a modified environment vector constructed from the given environment |
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57 // and the list of changes given in |changes|. Each key in the environment is |
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58 // matched against the first element of the pairs. In the event of a match, the |
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59 // value is replaced by the second of the pair, unless the second is empty, in |
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60 // which case the key-value is removed. |
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61 // |
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62 // This Windows version takes and returns a Windows-style environment block |
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63 // which is a concatenated list of null-terminated 16-bit strings. The end is |
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64 // marked by a double-null terminator. The size of the returned string will |
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65 // include the terminators. |
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66 BASE_EXPORT string16 AlterEnvironment(const wchar_t* env, |
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67 const EnvironmentMap& changes); |
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68 |
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69 #elif defined(OS_POSIX) |
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70 |
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71 typedef std::string NativeEnvironmentString; |
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72 typedef std::map<NativeEnvironmentString, NativeEnvironmentString> |
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73 EnvironmentMap; |
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74 |
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75 // See general comments for the Windows version above. |
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76 // |
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77 // This Posix version takes and returns a Posix-style environment block, which |
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78 // is a null-terminated list of pointers to null-terminated strings. The |
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79 // returned array will have appended to it the storage for the array itself so |
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80 // there is only one pointer to manage, but this means that you can't copy the |
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81 // array without keeping the original around. |
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82 BASE_EXPORT scoped_ptr<char*[]> AlterEnvironment( |
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83 const char* const* env, |
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84 const EnvironmentMap& changes); |
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85 |
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86 #endif |
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87 |
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88 } // namespace base |
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89 |
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90 #endif // BASE_ENVIRONMENT_H_ |