filename_cmp.c revision 1.1.1.1.6.1 
1/* File name comparison routine.
2
3   Copyright (C) 2007 Free Software Foundation, Inc.
4
5   This program is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation; either version 2, or (at your option)
8   any later version.
9
10   This program is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   GNU General Public License for more details.
14
15   You should have received a copy of the GNU General Public License
16   along with this program; if not, write to the Free Software Foundation,
17   Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
18
19#ifdef HAVE_CONFIG_H
20#include "config.h"
21#endif
22
23#ifdef HAVE_STRING_H
24#include <string.h>
25#endif
26
27#include "filenames.h"
28#include "safe-ctype.h"
29
30/*
31
32@deftypefn Extension int filename_cmp (const char *@var{s1}, const char *@var{s2})
33
34Return zero if the two file names @var{s1} and @var{s2} are equivalent.
35If not equivalent, the returned value is similar to what @code{strcmp}
36would return.  In other words, it returns a negative value if @var{s1}
37is less than @var{s2}, or a positive value if @var{s2} is greater than
38@var{s2}.
39
40This function does not normalize file names.  As a result, this function
41will treat filenames that are spelled differently as different even in
42the case when the two filenames point to the same underlying file.
43However, it does handle the fact that on DOS-like file systems, forward
44and backward slashes are equal.
45
46@end deftypefn
47
48*/
49
50int
51filename_cmp (const char *s1, const char *s2)
52{
53#if !defined(HAVE_DOS_BASED_FILE_SYSTEM) \
54    && !defined(HAVE_CASE_INSENSITIVE_FILE_SYSTEM)
55  return strcmp(s1, s2);
56#else
57  for (;;)
58    {
59      int c1 = *s1;
60      int c2 = *s2;
61
62#if defined (HAVE_CASE_INSENSITIVE_FILE_SYSTEM)
63      c1 = TOLOWER (c1);
64      c2 = TOLOWER (c2);
65#endif
66
67#if defined (HAVE_DOS_BASED_FILE_SYSTEM)
68      /* On DOS-based file systems, the '/' and the '\' are equivalent.  */
69      if (c1 == '/')
70        c1 = '\\';
71      if (c2 == '/')
72        c2 = '\\';
73#endif
74
75      if (c1 != c2)
76        return (c1 - c2);
77
78      if (c1 == '\0')
79        return 0;
80
81      s1++;
82      s2++;
83    }
84#endif
85}
86
87/*
88
89@deftypefn Extension int filename_ncmp (const char *@var{s1}, const char *@var{s2}, size_t @var{n})
90
91Return zero if the two file names @var{s1} and @var{s2} are equivalent
92in range @var{n}.
93If not equivalent, the returned value is similar to what @code{strncmp}
94would return.  In other words, it returns a negative value if @var{s1}
95is less than @var{s2}, or a positive value if @var{s2} is greater than
96@var{s2}.
97
98This function does not normalize file names.  As a result, this function
99will treat filenames that are spelled differently as different even in
100the case when the two filenames point to the same underlying file.
101However, it does handle the fact that on DOS-like file systems, forward
102and backward slashes are equal.
103
104@end deftypefn
105
106*/
107
108int
109filename_ncmp (const char *s1, const char *s2, size_t n)
110{
111#if !defined(HAVE_DOS_BASED_FILE_SYSTEM) \
112    && !defined(HAVE_CASE_INSENSITIVE_FILE_SYSTEM)
113  return strncmp(s1, s2, n);
114#else
115  if (!n)
116    return 0;
117  for (; n > 0; --n)
118  {
119      int c1 = *s1;
120      int c2 = *s2;
121
122#if defined (HAVE_CASE_INSENSITIVE_FILE_SYSTEM)
123      c1 = TOLOWER (c1);
124      c2 = TOLOWER (c2);
125#endif
126
127#if defined (HAVE_DOS_BASED_FILE_SYSTEM)
128      /* On DOS-based file systems, the '/' and the '\' are equivalent.  */
129      if (c1 == '/')
130        c1 = '\\';
131      if (c2 == '/')
132        c2 = '\\';
133#endif
134
135      if (c1 == '\0' || c1 != c2)
136        return (c1 - c2);
137
138      s1++;
139      s2++;
140  }
141  return 0;
142#endif
143}
144
145/*
146
147@deftypefn Extension hashval_t filename_hash (const void *@var{s})
148
149Return the hash value for file name @var{s} that will be compared
150using filename_cmp.
151This function is for use with hashtab.c hash tables.
152
153@end deftypefn
154
155*/
156
157hashval_t
158filename_hash (const void *s)
159{
160  /* The cast is for -Wc++-compat.  */
161  const unsigned char *str = (const unsigned char *) s;
162  hashval_t r = 0;
163  unsigned char c;
164
165  while ((c = *str++) != 0)
166    {
167      if (c == '\\')
168	c = '/';
169      c = TOLOWER (c);
170      r = r * 67 + c - 113;
171    }
172
173  return r;
174}
175
176/*
177
178@deftypefn Extension int filename_eq (const void *@var{s1}, const void *@var{s2})
179
180Return non-zero if file names @var{s1} and @var{s2} are equivalent.
181This function is for use with hashtab.c hash tables.
182
183@end deftypefn
184
185*/
186
187int
188filename_eq (const void *s1, const void *s2)
189{
190  /* The casts are for -Wc++-compat.  */
191  return filename_cmp ((const char *) s1, (const char *) s2) == 0;
192}
193