| 1 | /* $Id: RTPathCalcRelative.cpp 98103 2023-01-17 14:15:46Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * IPRT - RTPathCreateRelative.
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2013-2023 Oracle and/or its affiliates.
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox base platform packages, as
|
|---|
| 10 | * available from https://www.virtualbox.org.
|
|---|
| 11 | *
|
|---|
| 12 | * This program is free software; you can redistribute it and/or
|
|---|
| 13 | * modify it under the terms of the GNU General Public License
|
|---|
| 14 | * as published by the Free Software Foundation, in version 3 of the
|
|---|
| 15 | * License.
|
|---|
| 16 | *
|
|---|
| 17 | * This program is distributed in the hope that it will be useful, but
|
|---|
| 18 | * WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|---|
| 20 | * General Public License for more details.
|
|---|
| 21 | *
|
|---|
| 22 | * You should have received a copy of the GNU General Public License
|
|---|
| 23 | * along with this program; if not, see <https://www.gnu.org/licenses>.
|
|---|
| 24 | *
|
|---|
| 25 | * The contents of this file may alternatively be used under the terms
|
|---|
| 26 | * of the Common Development and Distribution License Version 1.0
|
|---|
| 27 | * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
|
|---|
| 28 | * in the VirtualBox distribution, in which case the provisions of the
|
|---|
| 29 | * CDDL are applicable instead of those of the GPL.
|
|---|
| 30 | *
|
|---|
| 31 | * You may elect to license modified versions of this file under the
|
|---|
| 32 | * terms and conditions of either the GPL or the CDDL or both.
|
|---|
| 33 | *
|
|---|
| 34 | * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
|
|---|
| 35 | */
|
|---|
| 36 |
|
|---|
| 37 |
|
|---|
| 38 | /*********************************************************************************************************************************
|
|---|
| 39 | * Header Files *
|
|---|
| 40 | *********************************************************************************************************************************/
|
|---|
| 41 | #include "internal/iprt.h"
|
|---|
| 42 | #include <iprt/path.h>
|
|---|
| 43 |
|
|---|
| 44 | #include <iprt/assert.h>
|
|---|
| 45 | #include <iprt/errcore.h>
|
|---|
| 46 | #include <iprt/string.h>
|
|---|
| 47 | #if RTPATH_STYLE == RTPATH_STR_F_STYLE_DOS
|
|---|
| 48 | # include <iprt/uni.h>
|
|---|
| 49 | #endif
|
|---|
| 50 | #include "internal/path.h"
|
|---|
| 51 |
|
|---|
| 52 |
|
|---|
| 53 | #if RTPATH_STYLE == RTPATH_STR_F_STYLE_DOS
|
|---|
| 54 | /** Helper for doing case insensitive comparison of a mismatching codepoint. */
|
|---|
| 55 | DECLINLINE(bool) rtPathCalcRelativeEqualICaseCodepoint(const char *pszPathFromStart, const char *pszPathFrom,
|
|---|
| 56 | const char *pszPathToStart, const char *pszPathTo)
|
|---|
| 57 | {
|
|---|
| 58 | RTUNICP ucFrom = RTStrGetCp(RTStrPrevCp(pszPathFromStart, pszPathFrom));
|
|---|
| 59 | RTUNICP ucTo = RTStrGetCp(RTStrPrevCp(pszPathToStart, pszPathTo));
|
|---|
| 60 | return ucFrom == ucTo
|
|---|
| 61 | || RTUniCpToLower(ucFrom) == RTUniCpToLower(ucTo)
|
|---|
| 62 | || RTUniCpToUpper(ucFrom) == RTUniCpToUpper(ucTo);
|
|---|
| 63 | }
|
|---|
| 64 | #endif
|
|---|
| 65 |
|
|---|
| 66 |
|
|---|
| 67 | RTDECL(int) RTPathCalcRelative(char *pszPathDst, size_t cbPathDst,
|
|---|
| 68 | const char *pszPathFrom, bool fFromFile,
|
|---|
| 69 | const char *pszPathTo)
|
|---|
| 70 | {
|
|---|
| 71 | AssertPtrReturn(pszPathDst, VERR_INVALID_POINTER);
|
|---|
| 72 | AssertReturn(cbPathDst, VERR_INVALID_PARAMETER);
|
|---|
| 73 | AssertPtrReturn(pszPathFrom, VERR_INVALID_POINTER);
|
|---|
| 74 | AssertPtrReturn(pszPathTo, VERR_INVALID_POINTER);
|
|---|
| 75 | #if RTPATH_STYLE == RTPATH_STR_F_STYLE_DOS
|
|---|
| 76 | const char * const pszPathFromStart = pszPathFrom;
|
|---|
| 77 | const char * const pszPathToStart = pszPathTo;
|
|---|
| 78 | #endif
|
|---|
| 79 |
|
|---|
| 80 | /*
|
|---|
| 81 | * Check for different root specifiers (drive letters), creating a relative path doesn't work here.
|
|---|
| 82 | */
|
|---|
| 83 | size_t offRootFrom = rtPathRootSpecLen(pszPathFrom);
|
|---|
| 84 | AssertReturn(offRootFrom > 0, VERR_INVALID_PARAMETER);
|
|---|
| 85 |
|
|---|
| 86 | size_t offRootTo = rtPathRootSpecLen(pszPathTo);
|
|---|
| 87 | AssertReturn(offRootTo > 0, VERR_INVALID_PARAMETER);
|
|---|
| 88 |
|
|---|
| 89 |
|
|---|
| 90 | /** @todo correctly deal with extra root slashes! */
|
|---|
| 91 | if (offRootFrom != offRootTo)
|
|---|
| 92 | return VERR_NOT_SUPPORTED;
|
|---|
| 93 |
|
|---|
| 94 | #if RTPATH_STYLE != RTPATH_STR_F_STYLE_DOS
|
|---|
| 95 | if (RTStrNCmp(pszPathFrom, pszPathTo, offRootFrom))
|
|---|
| 96 | return VERR_NOT_SUPPORTED;
|
|---|
| 97 | #else
|
|---|
| 98 | if (RTStrNICmp(pszPathFrom, pszPathTo, offRootFrom))
|
|---|
| 99 | {
|
|---|
| 100 | const char *pszFromCursor = pszPathFrom;
|
|---|
| 101 | const char *pszToCursor = pszPathTo;
|
|---|
| 102 | while ((size_t)(pszFromCursor - pszPathFrom) < offRootFrom)
|
|---|
| 103 | {
|
|---|
| 104 | RTUNICP ucFrom;
|
|---|
| 105 | int rc = RTStrGetCpEx(&pszFromCursor, &ucFrom);
|
|---|
| 106 | AssertRCReturn(rc, rc);
|
|---|
| 107 |
|
|---|
| 108 | RTUNICP ucTo;
|
|---|
| 109 | rc = RTStrGetCpEx(&pszToCursor, &ucTo);
|
|---|
| 110 | AssertRCReturn(rc, rc);
|
|---|
| 111 | if ( ucFrom != ucTo
|
|---|
| 112 | && RTUniCpToLower(ucFrom) != RTUniCpToLower(ucTo)
|
|---|
| 113 | && RTUniCpToUpper(ucFrom) != RTUniCpToUpper(ucTo)
|
|---|
| 114 | && (!RTPATH_IS_SLASH(ucFrom) || !RTPATH_IS_SLASH(ucTo)) )
|
|---|
| 115 | return VERR_NOT_SUPPORTED;
|
|---|
| 116 | }
|
|---|
| 117 | }
|
|---|
| 118 | #endif
|
|---|
| 119 |
|
|---|
| 120 | pszPathFrom += offRootFrom;
|
|---|
| 121 | pszPathTo += offRootTo;
|
|---|
| 122 |
|
|---|
| 123 | /*
|
|---|
| 124 | * Skip out the part of the path which is equal to both.
|
|---|
| 125 | */
|
|---|
| 126 | const char *pszStartOfFromComp = pszPathFrom;
|
|---|
| 127 | for (;;)
|
|---|
| 128 | {
|
|---|
| 129 | char const chFrom = *pszPathFrom;
|
|---|
| 130 | char const chTo = *pszPathTo;
|
|---|
| 131 | if (!RTPATH_IS_SLASH(chFrom))
|
|---|
| 132 | {
|
|---|
| 133 | if (chFrom == chTo)
|
|---|
| 134 | {
|
|---|
| 135 | if (chFrom)
|
|---|
| 136 | { /* likely */ }
|
|---|
| 137 | else
|
|---|
| 138 | {
|
|---|
| 139 | /* Special case: The two paths are equal. */
|
|---|
| 140 | if (fFromFile)
|
|---|
| 141 | {
|
|---|
| 142 | size_t cchComp = pszPathFrom - pszStartOfFromComp;
|
|---|
| 143 | if (cchComp < cbPathDst)
|
|---|
| 144 | {
|
|---|
| 145 | memcpy(pszPathDst, pszStartOfFromComp, cchComp);
|
|---|
| 146 | pszPathDst[cchComp] = '\0';
|
|---|
| 147 | return VINF_SUCCESS;
|
|---|
| 148 | }
|
|---|
| 149 | }
|
|---|
| 150 | else if (sizeof(".") <= cbPathDst)
|
|---|
| 151 | {
|
|---|
| 152 | memcpy(pszPathDst, ".", sizeof("."));
|
|---|
| 153 | return VINF_SUCCESS;
|
|---|
| 154 | }
|
|---|
| 155 | return VERR_BUFFER_OVERFLOW;
|
|---|
| 156 | }
|
|---|
| 157 | }
|
|---|
| 158 | #if RTPATH_STYLE == RTPATH_STR_F_STYLE_DOS
|
|---|
| 159 | else if (rtPathCalcRelativeEqualICaseCodepoint(pszPathFromStart, pszPathFrom + 1, pszPathToStart, pszPathTo + 1))
|
|---|
| 160 | { /* if not likely, then simpler code structure wise. */ }
|
|---|
| 161 | #endif
|
|---|
| 162 | else if (chFrom != '\0' || !RTPATH_IS_SLASH(chTo) || fFromFile)
|
|---|
| 163 | break;
|
|---|
| 164 | else
|
|---|
| 165 | {
|
|---|
| 166 | pszStartOfFromComp = pszPathFrom;
|
|---|
| 167 | do
|
|---|
| 168 | pszPathTo++;
|
|---|
| 169 | while (RTPATH_IS_SLASH(*pszPathTo));
|
|---|
| 170 | break;
|
|---|
| 171 | }
|
|---|
| 172 | pszPathFrom++;
|
|---|
| 173 | pszPathTo++;
|
|---|
| 174 | }
|
|---|
| 175 | else if (RTPATH_IS_SLASH(chTo))
|
|---|
| 176 | {
|
|---|
| 177 | /* Both have slashes. Skip any additional ones before taking down
|
|---|
| 178 | the start of the component for rewinding purposes. */
|
|---|
| 179 | do
|
|---|
| 180 | pszPathTo++;
|
|---|
| 181 | while (RTPATH_IS_SLASH(*pszPathTo));
|
|---|
| 182 | do
|
|---|
| 183 | pszPathFrom++;
|
|---|
| 184 | while (RTPATH_IS_SLASH(*pszPathFrom));
|
|---|
| 185 | pszStartOfFromComp = pszPathFrom;
|
|---|
| 186 | }
|
|---|
| 187 | else
|
|---|
| 188 | break;
|
|---|
| 189 | }
|
|---|
| 190 |
|
|---|
| 191 | /* Rewind to the start of the current component. */
|
|---|
| 192 | pszPathTo -= pszPathFrom - pszStartOfFromComp;
|
|---|
| 193 | pszPathFrom = pszStartOfFromComp;
|
|---|
| 194 |
|
|---|
| 195 | /* Paths point to the first non equal component now. */
|
|---|
| 196 |
|
|---|
| 197 | /*
|
|---|
| 198 | * Constructure the relative path.
|
|---|
| 199 | */
|
|---|
| 200 |
|
|---|
| 201 | /* Create the part to go up from pszPathFrom. */
|
|---|
| 202 | unsigned offDst = 0;
|
|---|
| 203 |
|
|---|
| 204 | if (!fFromFile && *pszPathFrom != '\0')
|
|---|
| 205 | {
|
|---|
| 206 | if (offDst + 3 < cbPathDst)
|
|---|
| 207 | {
|
|---|
| 208 | pszPathDst[offDst++] = '.';
|
|---|
| 209 | pszPathDst[offDst++] = '.';
|
|---|
| 210 | pszPathDst[offDst++] = RTPATH_SLASH;
|
|---|
| 211 | }
|
|---|
| 212 | else
|
|---|
| 213 | return VERR_BUFFER_OVERFLOW;
|
|---|
| 214 | }
|
|---|
| 215 |
|
|---|
| 216 | while (*pszPathFrom != '\0')
|
|---|
| 217 | {
|
|---|
| 218 | char ch;
|
|---|
| 219 | while ( (ch = *pszPathFrom) != '\0'
|
|---|
| 220 | && !RTPATH_IS_SLASH(*pszPathFrom))
|
|---|
| 221 | pszPathFrom++;
|
|---|
| 222 | while ( (ch = *pszPathFrom) != '\0'
|
|---|
| 223 | && RTPATH_IS_SLASH(ch))
|
|---|
| 224 | pszPathFrom++;
|
|---|
| 225 | if (!ch)
|
|---|
| 226 | break;
|
|---|
| 227 |
|
|---|
| 228 | if (offDst + 3 < cbPathDst)
|
|---|
| 229 | {
|
|---|
| 230 | pszPathDst[offDst++] = '.';
|
|---|
| 231 | pszPathDst[offDst++] = '.';
|
|---|
| 232 | pszPathDst[offDst++] = RTPATH_SLASH;
|
|---|
| 233 | }
|
|---|
| 234 | else
|
|---|
| 235 | return VERR_BUFFER_OVERFLOW;
|
|---|
| 236 | }
|
|---|
| 237 |
|
|---|
| 238 | /* Now append the rest of pszPathTo to the final path. */
|
|---|
| 239 | size_t cchTo = strlen(pszPathTo);
|
|---|
| 240 | if (offDst + cchTo <= cbPathDst)
|
|---|
| 241 | {
|
|---|
| 242 | memcpy(&pszPathDst[offDst], pszPathTo, cchTo);
|
|---|
| 243 | pszPathDst[offDst + cchTo] = '\0';
|
|---|
| 244 | return VINF_SUCCESS;
|
|---|
| 245 | }
|
|---|
| 246 | return VERR_BUFFER_OVERFLOW;
|
|---|
| 247 | }
|
|---|
| 248 |
|
|---|
