Fix nullptr dereference in FLAC++
[flac.git] / src / share / grabbag / file.c
1 /* grabbag - Convenience lib for various routines common to several tools
2  * Copyright (C) 2002-2009  Josh Coalson
3  * Copyright (C) 2011-2016  Xiph.Org Foundation
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * This library 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 GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this library; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
18  */
19
20 #ifdef HAVE_CONFIG_H
21 #  include <config.h>
22 #endif
23
24 #if defined _MSC_VER || defined __MINGW32__
25 #include <sys/utime.h> /* for utime() */
26 #include <io.h> /* for chmod(), _setmode(), unlink() */
27 #include <fcntl.h> /* for _O_BINARY */
28 #else
29 #include <sys/types.h> /* some flavors of BSD (like OS X) require this to get time_t */
30 #endif
31 #if defined __EMX__
32 #include <io.h> /* for setmode(), O_BINARY */
33 #include <fcntl.h> /* for _O_BINARY */
34 #endif
35 #include <sys/stat.h> /* for stat(), maybe chmod() */
36 #if defined _WIN32 && !defined __CYGWIN__
37 #else
38 #include <unistd.h> /* for unlink() */
39 #endif
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h> /* for strrchr() */
43 #if defined _WIN32 && !defined __CYGWIN__
44 // for GetFileInformationByHandle() etc
45 #include <windows.h>
46 #include <winbase.h>
47 #endif
48 #include "share/grabbag.h"
49 #include "share/compat.h"
50
51
52 void grabbag__file_copy_metadata(const char *srcpath, const char *destpath)
53 {
54         struct flac_stat_s srcstat;
55
56         if(0 == flac_stat(srcpath, &srcstat)) {
57 #if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE >= 200809L)
58                 struct timespec srctime[2] = {};
59                 srctime[0].tv_sec = srcstat.st_atime;
60                 srctime[1].tv_sec = srcstat.st_mtime;
61 #else
62                 struct utimbuf srctime;
63                 srctime.actime = srcstat.st_atime;
64                 srctime.modtime = srcstat.st_mtime;
65 #endif
66                 (void)flac_chmod(destpath, srcstat.st_mode);
67                 (void)flac_utime(destpath, &srctime);
68         }
69 }
70
71 FLAC__off_t grabbag__file_get_filesize(const char *srcpath)
72 {
73         struct flac_stat_s srcstat;
74
75         if(0 == flac_stat(srcpath, &srcstat))
76                 return srcstat.st_size;
77         else
78                 return -1;
79 }
80
81 const char *grabbag__file_get_basename(const char *srcpath)
82 {
83         const char *p;
84
85         p = strrchr(srcpath, '/');
86         if(0 == p) {
87                 p = strrchr(srcpath, '\\');
88                 if(0 == p)
89                         return srcpath;
90         }
91         return ++p;
92 }
93
94 FLAC__bool grabbag__file_change_stats(const char *filename, FLAC__bool read_only)
95 {
96         struct flac_stat_s stats;
97
98         if(0 == flac_stat(filename, &stats)) {
99 #if !defined _MSC_VER && !defined __MINGW32__
100                 if(read_only) {
101                         stats.st_mode &= ~S_IWUSR;
102                         stats.st_mode &= ~S_IWGRP;
103                         stats.st_mode &= ~S_IWOTH;
104                 }
105                 else {
106                         stats.st_mode |= S_IWUSR;
107                 }
108 #else
109                 if(read_only)
110                         stats.st_mode &= ~S_IWRITE;
111                 else
112                         stats.st_mode |= S_IWRITE;
113 #endif
114                 if(0 != flac_chmod(filename, stats.st_mode))
115                         return false;
116         }
117         else
118                 return false;
119
120         return true;
121 }
122
123 FLAC__bool grabbag__file_are_same(const char *f1, const char *f2)
124 {
125 #if defined _WIN32 && !defined __CYGWIN__
126         /* see
127          *  http://www.hydrogenaudio.org/forums/index.php?showtopic=49439&pid=444300&st=0
128          *  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/fs/getfileinformationbyhandle.asp
129          *  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/fs/by_handle_file_information_str.asp
130          *  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/fs/createfile.asp
131          * apparently both the files have to be open at the same time for the comparison to work
132          */
133         FLAC__bool same = false;
134         BY_HANDLE_FILE_INFORMATION info1, info2;
135         HANDLE h1, h2;
136         BOOL ok = 1;
137         h1 = CreateFile_utf8(f1, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
138         h2 = CreateFile_utf8(f2, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
139         if(h1 == INVALID_HANDLE_VALUE || h2 == INVALID_HANDLE_VALUE)
140                 ok = 0;
141         ok &= GetFileInformationByHandle(h1, &info1);
142         ok &= GetFileInformationByHandle(h2, &info2);
143         if(ok)
144                 same =
145                         info1.dwVolumeSerialNumber == info2.dwVolumeSerialNumber &&
146                         info1.nFileIndexHigh == info2.nFileIndexHigh &&
147                         info1.nFileIndexLow == info2.nFileIndexLow
148                 ;
149         if(h1 != INVALID_HANDLE_VALUE)
150                 CloseHandle(h1);
151         if(h2 != INVALID_HANDLE_VALUE)
152                 CloseHandle(h2);
153         return same;
154 #else
155         struct flac_stat_s s1, s2;
156         return f1 && f2 && flac_stat(f1, &s1) == 0 && flac_stat(f2, &s2) == 0 && s1.st_ino == s2.st_ino && s1.st_dev == s2.st_dev;
157 #endif
158 }
159
160 FLAC__bool grabbag__file_remove_file(const char *filename)
161 {
162         return grabbag__file_change_stats(filename, /*read_only=*/false) && 0 == flac_unlink(filename);
163 }
164
165 FILE *grabbag__file_get_binary_stdin(void)
166 {
167         /* if something breaks here it is probably due to the presence or
168          * absence of an underscore before the identifiers 'setmode',
169          * 'fileno', and/or 'O_BINARY'; check your system header files.
170          */
171 #if defined _MSC_VER || defined __MINGW32__
172         _setmode(_fileno(stdin), _O_BINARY);
173 #elif defined __EMX__
174         setmode(fileno(stdin), O_BINARY);
175 #endif
176
177         return stdin;
178 }
179
180 FILE *grabbag__file_get_binary_stdout(void)
181 {
182         /* if something breaks here it is probably due to the presence or
183          * absence of an underscore before the identifiers 'setmode',
184          * 'fileno', and/or 'O_BINARY'; check your system header files.
185          */
186 #if defined _MSC_VER || defined __MINGW32__
187         _setmode(_fileno(stdout), _O_BINARY);
188 #elif defined __EMX__
189         setmode(fileno(stdout), O_BINARY);
190 #endif
191
192         return stdout;
193 }