1 | /* $Id: RTEnvDupEx-generic.cpp 98103 2023-01-17 14:15:46Z vboxsync $ */
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2 | /** @file
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3 | * IPRT - Environment, RTEnvDupEx, generic.
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4 | */
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5 |
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6 | /*
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7 | * Copyright (C) 2010-2023 Oracle and/or its affiliates.
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8 | *
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9 | * This file is part of VirtualBox base platform packages, as
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10 | * available from https://www.virtualbox.org.
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11 | *
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12 | * This program is free software; you can redistribute it and/or
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13 | * modify it under the terms of the GNU General Public License
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14 | * as published by the Free Software Foundation, in version 3 of the
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15 | * License.
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16 | *
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17 | * This program is distributed in the hope that it will be useful, but
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18 | * WITHOUT ANY WARRANTY; without even the implied warranty of
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19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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20 | * General Public License for more details.
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21 | *
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22 | * You should have received a copy of the GNU General Public License
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23 | * along with this program; if not, see <https://www.gnu.org/licenses>.
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24 | *
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25 | * The contents of this file may alternatively be used under the terms
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26 | * of the Common Development and Distribution License Version 1.0
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27 | * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
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28 | * in the VirtualBox distribution, in which case the provisions of the
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29 | * CDDL are applicable instead of those of the GPL.
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30 | *
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31 | * You may elect to license modified versions of this file under the
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32 | * terms and conditions of either the GPL or the CDDL or both.
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33 | *
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34 | * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
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35 | */
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36 |
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37 |
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38 | /*********************************************************************************************************************************
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39 | * Header Files *
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40 | *********************************************************************************************************************************/
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41 | #include <iprt/env.h>
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42 | #include "internal/iprt.h"
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43 |
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44 | #include <iprt/assert.h>
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45 | #include <iprt/errcore.h>
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46 | #include <iprt/string.h>
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47 |
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48 |
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49 |
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50 | RTDECL(char *) RTEnvDupEx(RTENV Env, const char *pszVar)
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51 | {
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52 | /*
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53 | * Try with a small buffer. This helps avoid allocating a heap buffer for
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54 | * variables that doesn't exist.
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55 | */
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56 | char szSmall[256];
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57 | int rc = RTEnvGetEx(Env, pszVar, szSmall, sizeof(szSmall), NULL);
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58 | if (RT_SUCCESS(rc))
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59 | return RTStrDup(szSmall);
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60 | if (rc != VERR_BUFFER_OVERFLOW)
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61 | return NULL;
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62 |
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63 | /*
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64 | * It's a big bugger.
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65 | */
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66 | size_t cbBuf = _1K;
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67 | do
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68 | {
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69 | char *pszBuf = RTStrAlloc(cbBuf);
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70 | AssertBreak(pszBuf);
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71 |
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72 | rc = RTEnvGetEx(Env, pszVar, pszBuf, cbBuf, NULL);
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73 | if (RT_SUCCESS(rc))
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74 | return pszBuf;
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75 |
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76 | RTStrFree(pszBuf);
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77 |
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78 | /* If overflow double the buffer. */
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79 | if (rc != VERR_BUFFER_OVERFLOW)
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80 | break;
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81 | cbBuf *= 2;
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82 | } while (cbBuf < _64M);
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83 |
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84 | return NULL;
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85 | }
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86 | RT_EXPORT_SYMBOL(RTEnvDupEx);
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87 |
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