1 /*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
4
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
8
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
12
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../../SDL_internal.h"
22
23 #ifdef SDL_FILESYSTEM_UNIX
24
25 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
26 /* System dependent filesystem routines */
27
28 #include <errno.h>
29 #include <stdio.h>
30 #include <unistd.h>
31 #include <stdlib.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include <limits.h>
35
36 #if defined(__FREEBSD__) || defined(__OPENBSD__)
37 #include <sys/sysctl.h>
38 #endif
39
40 #include "SDL_error.h"
41 #include "SDL_stdinc.h"
42 #include "SDL_filesystem.h"
43
44 static char *
readSymLink(const char * path)45 readSymLink(const char *path)
46 {
47 char *retval = NULL;
48 ssize_t len = 64;
49 ssize_t rc = -1;
50
51 while (1)
52 {
53 char *ptr = (char *) SDL_realloc(retval, (size_t) len);
54 if (ptr == NULL) {
55 SDL_OutOfMemory();
56 break;
57 }
58
59 retval = ptr;
60
61 rc = readlink(path, retval, len);
62 if (rc == -1) {
63 break; /* not a symlink, i/o error, etc. */
64 } else if (rc < len) {
65 retval[rc] = '\0'; /* readlink doesn't null-terminate. */
66 return retval; /* we're good to go. */
67 }
68
69 len *= 2; /* grow buffer, try again. */
70 }
71
72 SDL_free(retval);
73 return NULL;
74 }
75
76
77 char *
SDL_GetBasePath(void)78 SDL_GetBasePath(void)
79 {
80 char *retval = NULL;
81
82 #if defined(__FREEBSD__)
83 char fullpath[PATH_MAX];
84 size_t buflen = sizeof (fullpath);
85 const int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
86 if (sysctl(mib, SDL_arraysize(mib), fullpath, &buflen, NULL, 0) != -1) {
87 retval = SDL_strdup(fullpath);
88 if (!retval) {
89 SDL_OutOfMemory();
90 return NULL;
91 }
92 }
93 #endif
94 #if defined(__OPENBSD__)
95 char **retvalargs;
96 size_t len;
97 const int mib[] = { CTL_KERN, KERN_PROC_ARGS, getpid(), KERN_PROC_ARGV };
98 if (sysctl(mib, 4, NULL, &len, NULL, 0) != -1) {
99 retvalargs = SDL_malloc(len);
100 if (!retvalargs) {
101 SDL_OutOfMemory();
102 return NULL;
103 }
104 sysctl(mib, 4, retvalargs, &len, NULL, 0);
105 retval = SDL_malloc(PATH_MAX + 1);
106 if (retval)
107 realpath(retvalargs[0], retval);
108
109 SDL_free(retvalargs);
110 }
111 #endif
112 #if defined(__SOLARIS__)
113 const char *path = getexecname();
114 if ((path != NULL) && (path[0] == '/')) { /* must be absolute path... */
115 retval = SDL_strdup(path);
116 if (!retval) {
117 SDL_OutOfMemory();
118 return NULL;
119 }
120 }
121 #endif
122
123 /* is a Linux-style /proc filesystem available? */
124 if (!retval && (access("/proc", F_OK) == 0)) {
125 #if defined(__FREEBSD__)
126 retval = readSymLink("/proc/curproc/file");
127 #elif defined(__NETBSD__)
128 retval = readSymLink("/proc/curproc/exe");
129 #else
130 retval = readSymLink("/proc/self/exe"); /* linux. */
131 #endif
132 if (retval == NULL) {
133 /* older kernels don't have /proc/self ... try PID version... */
134 char path[64];
135 const int rc = (int) SDL_snprintf(path, sizeof(path),
136 "/proc/%llu/exe",
137 (unsigned long long) getpid());
138 if ( (rc > 0) && (rc < sizeof(path)) ) {
139 retval = readSymLink(path);
140 }
141 }
142 }
143
144 /* If we had access to argv[0] here, we could check it for a path,
145 or troll through $PATH looking for it, too. */
146
147 if (retval != NULL) { /* chop off filename. */
148 char *ptr = SDL_strrchr(retval, '/');
149 if (ptr != NULL) {
150 *(ptr+1) = '\0';
151 } else { /* shouldn't happen, but just in case... */
152 SDL_free(retval);
153 retval = NULL;
154 }
155 }
156
157 if (retval != NULL) {
158 /* try to shrink buffer... */
159 char *ptr = (char *) SDL_realloc(retval, strlen(retval) + 1);
160 if (ptr != NULL)
161 retval = ptr; /* oh well if it failed. */
162 }
163
164 return retval;
165 }
166
167 char *
SDL_GetPrefPath(const char * org,const char * app)168 SDL_GetPrefPath(const char *org, const char *app)
169 {
170 /*
171 * We use XDG's base directory spec, even if you're not on Linux.
172 * This isn't strictly correct, but the results are relatively sane
173 * in any case.
174 *
175 * http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
176 */
177 const char *envr = SDL_getenv("XDG_DATA_HOME");
178 const char *append;
179 char *retval = NULL;
180 char *ptr = NULL;
181 size_t len = 0;
182
183 if (!envr) {
184 /* You end up with "$HOME/.local/share/Game Name 2" */
185 envr = SDL_getenv("HOME");
186 if (!envr) {
187 /* we could take heroic measures with /etc/passwd, but oh well. */
188 SDL_SetError("neither XDG_DATA_HOME nor HOME environment is set");
189 return NULL;
190 }
191 append = "/.local/share/";
192 } else {
193 append = "/";
194 }
195
196 len = SDL_strlen(envr);
197 if (envr[len - 1] == '/')
198 append += 1;
199
200 len += SDL_strlen(append) + SDL_strlen(org) + SDL_strlen(app) + 3;
201 retval = (char *) SDL_malloc(len);
202 if (!retval) {
203 SDL_OutOfMemory();
204 return NULL;
205 }
206
207 SDL_snprintf(retval, len, "%s%s%s/%s/", envr, append, org, app);
208
209 for (ptr = retval+1; *ptr; ptr++) {
210 if (*ptr == '/') {
211 *ptr = '\0';
212 if (mkdir(retval, 0700) != 0 && errno != EEXIST)
213 goto error;
214 *ptr = '/';
215 }
216 }
217 if (mkdir(retval, 0700) != 0 && errno != EEXIST) {
218 error:
219 SDL_SetError("Couldn't create directory '%s': '%s'", retval, strerror(errno));
220 SDL_free(retval);
221 return NULL;
222 }
223
224 return retval;
225 }
226
227 #endif /* SDL_FILESYSTEM_UNIX */
228
229 /* vi: set ts=4 sw=4 expandtab: */
230