1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/* $Id: RTPathCalcRelative.cpp $ */
/** @file
* IPRT - RTPathCreateRelative.
*/
/*
* Copyright (C) 2013-2019 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*/
/*********************************************************************************************************************************
* Header Files *
*********************************************************************************************************************************/
#include "internal/iprt.h"
#include <iprt/path.h>
#include <iprt/assert.h>
#include <iprt/errcore.h>
#include <iprt/string.h>
#if RTPATH_STYLE == RTPATH_STR_F_STYLE_DOS
# include <iprt/uni.h>
#endif
#include "internal/path.h"
#if RTPATH_STYLE == RTPATH_STR_F_STYLE_DOS
/** Helper for doing case insensitive comparison of a mismatching codepoint. */
DECLINLINE(bool) rtPathCalcRelativeEqualICaseCodepoint(const char *pszPathFromStart, const char *pszPathFrom,
const char *pszPathToStart, const char *pszPathTo)
{
RTUNICP ucFrom = RTStrGetCp(RTStrPrevCp(pszPathFromStart, pszPathFrom));
RTUNICP ucTo = RTStrGetCp(RTStrPrevCp(pszPathToStart, pszPathTo));
return ucFrom == ucTo
|| RTUniCpToLower(ucFrom) == RTUniCpToLower(ucTo)
|| RTUniCpToUpper(ucFrom) == RTUniCpToUpper(ucTo);
}
#endif
RTDECL(int) RTPathCalcRelative(char *pszPathDst, size_t cbPathDst,
const char *pszPathFrom, bool fFromFile,
const char *pszPathTo)
{
AssertPtrReturn(pszPathDst, VERR_INVALID_POINTER);
AssertReturn(cbPathDst, VERR_INVALID_PARAMETER);
AssertPtrReturn(pszPathFrom, VERR_INVALID_POINTER);
AssertPtrReturn(pszPathTo, VERR_INVALID_POINTER);
#if RTPATH_STYLE == RTPATH_STR_F_STYLE_DOS
const char * const pszPathFromStart = pszPathFrom;
const char * const pszPathToStart = pszPathTo;
#endif
/*
* Check for different root specifiers (drive letters), creating a relative path doesn't work here.
*/
size_t offRootFrom = rtPathRootSpecLen(pszPathFrom);
AssertReturn(offRootFrom > 0, VERR_INVALID_PARAMETER);
size_t offRootTo = rtPathRootSpecLen(pszPathTo);
AssertReturn(offRootTo > 0, VERR_INVALID_PARAMETER);
/** @todo correctly deal with extra root slashes! */
if (offRootFrom != offRootTo)
return VERR_NOT_SUPPORTED;
#if RTPATH_STYLE != RTPATH_STR_F_STYLE_DOS
if (RTStrNCmp(pszPathFrom, pszPathTo, offRootFrom))
return VERR_NOT_SUPPORTED;
#else
if (RTStrNICmp(pszPathFrom, pszPathTo, offRootFrom))
{
const char *pszFromCursor = pszPathFrom;
const char *pszToCursor = pszPathTo;
while ((size_t)(pszFromCursor - pszPathFrom) < offRootFrom)
{
RTUNICP ucFrom;
int rc = RTStrGetCpEx(&pszFromCursor, &ucFrom);
AssertRCReturn(rc, rc);
RTUNICP ucTo;
rc = RTStrGetCpEx(&pszToCursor, &ucTo);
AssertRCReturn(rc, rc);
if ( ucFrom != ucTo
&& RTUniCpToLower(ucFrom) != RTUniCpToLower(ucTo)
&& RTUniCpToUpper(ucFrom) != RTUniCpToUpper(ucTo)
&& (!RTPATH_IS_SLASH(ucFrom) || !RTPATH_IS_SLASH(ucTo)) )
return VERR_NOT_SUPPORTED;
}
}
#endif
pszPathFrom += offRootFrom;
pszPathTo += offRootTo;
/*
* Skip out the part of the path which is equal to both.
*/
const char *pszStartOfFromComp = pszPathFrom;
for (;;)
{
char const chFrom = *pszPathFrom;
char const chTo = *pszPathTo;
if (!RTPATH_IS_SLASH(chFrom))
{
if (chFrom == chTo)
{
if (chFrom)
{ /* likely */ }
else
{
/* Special case: The two paths are equal. */
if (fFromFile)
{
size_t cchComp = pszPathFrom - pszStartOfFromComp;
if (cchComp < cbPathDst)
{
memcpy(pszPathDst, pszStartOfFromComp, cchComp);
pszPathDst[cchComp] = '\0';
return VINF_SUCCESS;
}
}
else if (sizeof(".") <= cbPathDst)
{
memcpy(pszPathDst, ".", sizeof("."));
return VINF_SUCCESS;
}
return VERR_BUFFER_OVERFLOW;
}
}
#if RTPATH_STYLE == RTPATH_STR_F_STYLE_DOS
else if (rtPathCalcRelativeEqualICaseCodepoint(pszPathFromStart, pszPathFrom + 1, pszPathToStart, pszPathTo + 1))
{ /* if not likely, then simpler code structure wise. */ }
#endif
else if (chFrom != '\0' || !RTPATH_IS_SLASH(chTo) || fFromFile)
break;
else
{
pszStartOfFromComp = pszPathFrom;
do
pszPathTo++;
while (RTPATH_IS_SLASH(*pszPathTo));
break;
}
pszPathFrom++;
pszPathTo++;
}
else if (RTPATH_IS_SLASH(chTo))
{
/* Both have slashes. Skip any additional ones before taking down
the start of the component for rewinding purposes. */
do
pszPathTo++;
while (RTPATH_IS_SLASH(*pszPathTo));
do
pszPathFrom++;
while (RTPATH_IS_SLASH(*pszPathFrom));
pszStartOfFromComp = pszPathFrom;
}
else
break;
}
/* Rewind to the start of the current component. */
pszPathTo -= pszPathFrom - pszStartOfFromComp;
pszPathFrom = pszStartOfFromComp;
/* Paths point to the first non equal component now. */
/*
* Constructure the relative path.
*/
/* Create the part to go up from pszPathFrom. */
unsigned offDst = 0;
if (!fFromFile && *pszPathFrom != '\0')
{
if (offDst + 3 < cbPathDst)
{
pszPathDst[offDst++] = '.';
pszPathDst[offDst++] = '.';
pszPathDst[offDst++] = RTPATH_SLASH;
}
else
return VERR_BUFFER_OVERFLOW;
}
while (*pszPathFrom != '\0')
{
char ch;
while ( (ch = *pszPathFrom) != '\0'
&& !RTPATH_IS_SLASH(*pszPathFrom))
pszPathFrom++;
while ( (ch = *pszPathFrom) != '\0'
&& RTPATH_IS_SLASH(ch))
pszPathFrom++;
if (!ch)
break;
if (offDst + 3 < cbPathDst)
{
pszPathDst[offDst++] = '.';
pszPathDst[offDst++] = '.';
pszPathDst[offDst++] = RTPATH_SLASH;
}
else
return VERR_BUFFER_OVERFLOW;
}
/* Now append the rest of pszPathTo to the final path. */
size_t cchTo = strlen(pszPathTo);
if (offDst + cchTo <= cbPathDst)
{
memcpy(&pszPathDst[offDst], pszPathTo, cchTo);
pszPathDst[offDst + cchTo] = '\0';
return VINF_SUCCESS;
}
return VERR_BUFFER_OVERFLOW;
}
|
