1 /*
2 ** Code implementing read only functionality copied from
3 ** src/lfs.c at commit 2fd989cd6c777583be1c93616018c55b2cbb1bcf:
4 **
5 ** LuaFileSystem 1.6.2
6 ** Copyright 2003-2014 Kepler Project
7 ** http://www.keplerproject.org/luafilesystem
8 **
9 ** File system manipulation library.
10 ** This library offers these functions:
11 ** lfs.attributes (filepath [, attributename])
12 ** lfs.chdir (path)
13 ** lfs.currentdir ()
14 ** lfs.dir (path)
15 **
16 ** $Id: lfs.c,v 1.61 2009/07/04 02:10:16 mascarenhas Exp $
17 */
18
19 #include <dirent.h>
20 #include <errno.h>
21 #include <fcntl.h>
22 #include <string.h>
23 #include <sys/stat.h>
24 #include <sys/types.h>
25 #include <unistd.h>
26
27 #include "lua.h"
28 #include "lauxlib.h"
29 #include "lualib.h"
30
31 #define chdir_error strerror(errno)
32
33 /* Size of path buffer string, stolen from pwd.c */
34 #ifndef PATH_MAX
35 # ifdef NAME_MAX
36 # define PATH_MAX NAME_MAX
37 # elif FILENAME_MAX
38 # define PATH_MAX FILENAME_MAX
39 # else
40 # define PATH_MAX 256
41 # endif /* NAME_MAX */
42 #endif /* PATH_MAX */
43
44
45 #define DIR_METATABLE "directory metatable"
46 typedef struct dir_data {
47 int closed;
48 DIR *dir;
49 } dir_data;
50
51
52 #define STAT_STRUCT struct stat
53 #define STAT_FUNC stat_via_fstat
54
55 /* Emulate stat via fstat */
stat_via_fstat(const char * path,struct stat * buf)56 int stat_via_fstat (const char *path, struct stat *buf)
57 {
58 int fd = open (path, O_RDONLY);
59 if (fd == -1) {
60 DIR *dir = opendir (path);
61 if (!dir) return -1;
62 closedir (dir);
63 buf->st_mode=S_IFDIR;
64 buf->st_size=0;
65 return 0;
66 }
67 if (fstat (fd, buf) == -1) {
68 int err = errno;
69 close (fd);
70 errno = err;
71 return -1;
72 }
73 close (fd);
74 return 0;
75 }
76
77 /*
78 ** This function changes the working (current) directory
79 */
change_dir(lua_State * L)80 static int change_dir (lua_State *L) {
81 const char *path = luaL_checkstring(L, 1);
82 if (chdir(path)) {
83 lua_pushnil (L);
84 lua_pushfstring (L,"Unable to change working directory to '%s'\n%s\n",
85 path, chdir_error);
86 return 2;
87 } else {
88 lua_pushboolean (L, 1);
89 return 1;
90 }
91 }
92
93
94 /*
95 ** This function returns the current directory
96 ** If unable to get the current directory, it returns nil
97 ** and a string describing the error
98 */
get_dir(lua_State * L)99 static int get_dir (lua_State *L) {
100 char *path;
101 /* Passing (NULL, 0) is not guaranteed to work. Use a temp buffer and size instead. */
102 char buf[PATH_MAX];
103 if ((path = getcwd(buf, PATH_MAX)) == NULL) {
104 lua_pushnil(L);
105 lua_pushstring(L, strerror(errno));
106 return 2;
107 }
108 else {
109 lua_pushstring(L, path);
110 return 1;
111 }
112 }
113
114
115 /*
116 ** Directory iterator
117 */
dir_iter(lua_State * L)118 static int dir_iter (lua_State *L) {
119 struct dirent *entry;
120 dir_data *d = (dir_data *)luaL_checkudata (L, 1, DIR_METATABLE);
121 luaL_argcheck (L, d->closed == 0, 1, "closed directory");
122 if ((entry = readdir (d->dir)) != NULL) {
123 lua_pushstring (L, entry->d_name);
124 return 1;
125 } else {
126 /* no more entries => close directory */
127 closedir (d->dir);
128 d->closed = 1;
129 return 0;
130 }
131 }
132
133
134 /*
135 ** Closes directory iterators
136 */
dir_close(lua_State * L)137 static int dir_close (lua_State *L) {
138 dir_data *d = (dir_data *)lua_touserdata (L, 1);
139 if (!d->closed && d->dir) {
140 closedir (d->dir);
141 }
142 d->closed = 1;
143 return 0;
144 }
145
146
147 /*
148 ** Factory of directory iterators
149 */
dir_iter_factory(lua_State * L)150 static int dir_iter_factory (lua_State *L) {
151 const char *path = luaL_checkstring (L, 1);
152 dir_data *d;
153 lua_pushcfunction (L, dir_iter);
154 d = (dir_data *) lua_newuserdata (L, sizeof(dir_data));
155 luaL_getmetatable (L, DIR_METATABLE);
156 lua_setmetatable (L, -2);
157 d->closed = 0;
158 d->dir = opendir (path);
159 if (d->dir == NULL)
160 luaL_error (L, "cannot open %s: %s", path, strerror (errno));
161 return 2;
162 }
163
164
165 /*
166 ** Creates directory metatable.
167 */
dir_create_meta(lua_State * L)168 static int dir_create_meta (lua_State *L) {
169 luaL_newmetatable (L, DIR_METATABLE);
170
171 /* Method table */
172 lua_newtable(L);
173 lua_pushcfunction (L, dir_iter);
174 lua_setfield(L, -2, "next");
175 lua_pushcfunction (L, dir_close);
176 lua_setfield(L, -2, "close");
177
178 /* Metamethods */
179 lua_setfield(L, -2, "__index");
180 lua_pushcfunction (L, dir_close);
181 lua_setfield (L, -2, "__gc");
182 return 1;
183 }
184
185
186 /*
187 ** Convert the inode protection mode to a string.
188 */
mode2string(mode_t mode)189 static const char *mode2string (mode_t mode) {
190 if ( S_ISREG(mode) )
191 return "file";
192 else if ( S_ISDIR(mode) )
193 return "directory";
194 else if ( S_ISLNK(mode) )
195 return "link";
196 else if ( S_ISSOCK(mode) )
197 return "socket";
198 else if ( S_ISFIFO(mode) )
199 return "named pipe";
200 else if ( S_ISCHR(mode) )
201 return "char device";
202 else if ( S_ISBLK(mode) )
203 return "block device";
204 else
205 return "other";
206 }
207
208
209 /* inode protection mode */
push_st_mode(lua_State * L,STAT_STRUCT * info)210 static void push_st_mode (lua_State *L, STAT_STRUCT *info) {
211 lua_pushstring (L, mode2string (info->st_mode));
212 }
213 /* file size, in bytes */
push_st_size(lua_State * L,STAT_STRUCT * info)214 static void push_st_size (lua_State *L, STAT_STRUCT *info) {
215 lua_pushnumber (L, (lua_Number)info->st_size);
216 }
push_invalid(lua_State * L,STAT_STRUCT * info)217 static void push_invalid (lua_State *L, STAT_STRUCT *info) {
218 luaL_error(L, "invalid attribute name");
219 info->st_size = 0; /* never reached */
220 }
221
222 typedef void (*_push_function) (lua_State *L, STAT_STRUCT *info);
223
224 struct _stat_members {
225 const char *name;
226 _push_function push;
227 };
228
229 struct _stat_members members[] = {
230 { "mode", push_st_mode },
231 { "size", push_st_size },
232 { NULL, push_invalid }
233 };
234
235 /*
236 ** Get file or symbolic link information
237 */
_file_info_(lua_State * L,int (* st)(const char *,STAT_STRUCT *))238 static int _file_info_ (lua_State *L, int (*st)(const char*, STAT_STRUCT*)) {
239 int i;
240 STAT_STRUCT info;
241 const char *file = luaL_checkstring (L, 1);
242
243 if (st(file, &info)) {
244 lua_pushnil (L);
245 lua_pushfstring (L, "cannot obtain information from file `%s'", file);
246 return 2;
247 }
248 if (lua_isstring (L, 2)) {
249 int v;
250 const char *member = lua_tostring (L, 2);
251 if (strcmp (member, "mode") == 0) v = 0;
252 #ifndef _WIN32
253 else if (strcmp (member, "blocks") == 0) v = 11;
254 else if (strcmp (member, "blksize") == 0) v = 12;
255 #endif
256 else /* look for member */
257 for (v = 1; members[v].name; v++)
258 if (*members[v].name == *member)
259 break;
260 /* push member value and return */
261 members[v].push (L, &info);
262 return 1;
263 } else if (!lua_istable (L, 2))
264 /* creates a table if none is given */
265 lua_newtable (L);
266 /* stores all members in table on top of the stack */
267 for (i = 0; members[i].name; i++) {
268 lua_pushstring (L, members[i].name);
269 members[i].push (L, &info);
270 lua_rawset (L, -3);
271 }
272 return 1;
273 }
274
275
276 /*
277 ** Get file information using stat.
278 */
file_info(lua_State * L)279 static int file_info (lua_State *L) {
280 return _file_info_ (L, STAT_FUNC);
281 }
282
283
284 static const struct luaL_Reg fslib[] = {
285 {"attributes", file_info},
286 {"chdir", change_dir},
287 {"currentdir", get_dir},
288 {"dir", dir_iter_factory},
289 {NULL, NULL},
290 };
291
luaopen_lfs(lua_State * L)292 LUALIB_API int luaopen_lfs (lua_State *L) {
293 dir_create_meta (L);
294 luaL_newlib (L, fslib);
295 return 1;
296 }
297