summaryrefslogtreecommitdiff
path: root/luafilesystem.c
blob: ea0c1f7f1ac7ee796c155b8b1784bbd375aa1223 (plain)
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
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
/*
** File system manipulation library.
** This library offers these functions:
**   luafilesystem.attributes (filepath [, attributename])
**   luafilesystem.chdir (path)
**   luafilesystem.currentdir ()
**   luafilesystem.dir (path)
**   luafilesystem.mkdir (path)
**   luafilesystem.lock (fh, mode)
**   luafilesystem.unlock (fh)
**
** $Id: luafilesystem.c,v 1.1.1.1 2004/07/27 14:15:24 tomas Exp $
*/

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

#ifdef WIN32
#include <direct.h>
#include <io.h>
#include <sys/locking.h>
#else
#include <unistd.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#endif

#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>

#include "luafilesystem.h"

/* Define 'strerror' for systems that do not implement it */
#ifdef NO_STRERROR
#define strerror(_)	"System unable to describe the error"
#endif

/* Define 'getcwd' for systems that do not implement it */
#ifdef NO_GETCWD
#define getcwd(p,s)	NULL
#define getcwd_error	"Function 'getcwd' not provided by system"
#else
#define getcwd_error	strerror(errno)
#endif

#define DIR_METATABLE "directory metatable"
#define MAX_DIR_LENGTH 1023
#ifdef _WIN32
typedef struct dir_data {
	long hFile;
	char pattern[MAX_DIR_LENGTH+1];
} dir_data;
#endif


/*
** This function changes the working (current) directory
*/
static int change_dir (lua_State *L) {
	const char *path = luaL_checkstring(L, 1);
	if (chdir(path)) 
		luaL_error(L,"Unable to change working directory to '%s'\n%s\n",
				path, chdir_error);
	return 0;
}

/*
** This function returns the current directory
** If unable to get the current directory, it returns nil
**  and a string describing the error
*/
static int get_dir (lua_State *L) {
	char path[255+2];
	if (getcwd(path, 255) == NULL) {
		lua_pushnil(L);
		lua_pushstring(L, getcwd_error);
		return 2;
	}
	else {
		lua_pushstring(L, path);
		return 1;
	}
}

/*
** Check if the given element on the stack is a file and returns it.
*/
static FILE *check_file (lua_State *L, int idx, const char *funcname) {
	FILE **fh = (FILE **)luaL_checkudata (L, idx, "FILE*");
	if (fh == NULL) {
		luaL_error (L, "%s: not a file", funcname);
		return 0;
	} else if (*fh == NULL) {
		luaL_error (L, "%s: closed file", funcname);
		return 0;
	} else
		return *fh;
}


/*
**
*/
static int _file_lock (lua_State *L, FILE *fh, const char *mode, const long start, long len, const char *funcname) {
	int code;
#ifdef WIN32
	/* lkmode valid values are:
	   _LK_LOCK    Locks the specified bytes. If the bytes cannot be locked, the program immediately tries again after 1 second. If, after 10 attempts, the bytes cannot be locked, the constant returns an error.
	   _LK_NBLCK   Locks the specified bytes. If the bytes cannot be locked, the constant returns an error.
	   _LK_NBRLCK  Same as _LK_NBLCK.
	   _LK_RLCK    Same as _LK_LOCK.
	   _LK_UNLCK   Unlocks the specified bytes, which must have been previously locked.

	   Regions should be locked only briefly and should be unlocked before closing a file or exiting the program.

	   http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/_crt__locking.asp
	*/
	int lkmode;
	switch (*mode) {
		case 'r': lkmode = _LK_NBLCK; break;
		case 'w': lkmode = _LK_NBLCK; break;
		case 'u': lkmode = _LK_UNLCK; break;
		default : luaL_error (L, "%s: invalid mode", funcname);
	}
	if (!len) {
		fseek (fh, 0L, SEEK_END);
		len = ftell (fh);
	}
	fseek (fh, start, SEEK_SET);
	code = _locking (fileno(fh), lkmode, len);
#else
	struct flock f;
	switch (*mode) {
		case 'w': f.l_type = F_WRLCK; break;
		case 'r': f.l_type = F_RDLCK; break;
		case 'u': f.l_type = F_UNLCK; break;
		default : luaL_error (L, "%s: invalid mode", funcname);
	}
	f.l_whence = SEEK_SET;
	f.l_start = (off_t)start;
	f.l_len = (off_t)len;
	code = fcntl (fileno(fh), F_SETLK, &f);
#endif
	return (code != -1);
}


/*
** Locks a file.
** @param #1 File handle.
** @param #2 String with lock mode ('w'rite, 'r'ead).
** @param #3 Number with start position (optional).
** @param #4 Number with length (optional).
*/
static int file_lock (lua_State *L) {
	FILE *fh = check_file (L, 1, "lock");
	const char *mode = luaL_checkstring (L, 2);
	const long start = luaL_optlong (L, 3, 0);
	long len = luaL_optlong (L, 4, 0);
	if (_file_lock (L, fh, mode, start, len, "lock")) {
		lua_pushboolean (L, 1);
		return 1;
	} else {
		lua_pushboolean (L, 0);
		lua_pushfstring (L, "%s", strerror(errno));
		return 2;
	}
}


/*
** Unlocks a file.
** @param #1 File handle.
** @param #2 Number with start position (optional).
** @param #3 Number with length (optional).
*/
static int file_unlock (lua_State *L) {
	FILE *fh = check_file (L, 1, "unlock");
	const long start = luaL_optlong (L, 2, 0);
	long len = luaL_optlong (L, 3, 0);
	if (_file_lock (L, fh, "u", start, len, "unlock")) {
		lua_pushboolean (L, 1);
		return 1;
	} else {
		lua_pushboolean (L, 0);
		lua_pushfstring (L, "%s", strerror(errno));
		return 2;
	}
}


/*
static void cgilua_sleep( lua_State *L )
{
  unsigned int usec = (unsigned int)luaL_check_number( L, 1 );

#ifndef WIN32
  sleep( (unsigned int)ceil( usec/1000.0 ));
#else
  Sleep( (DWORD)usec );
#endif
}

static void cgilua_filesize( lua_State *L )
{
  struct stat info;
  char *file = luaL_check_string( L, 1 );

  if (stat(file, &info))
  {
    lua_pushnil( L );
    lua_pushstring( L, "Cannot retrieve stat info from file" );
    return;
  }
  lua_pushnumber(L, info.st_size);
}
*/

static int make_dir (lua_State *L) {
	const char *path = luaL_checkstring (L, 1);
	int fail;
#ifdef WIN32
	int oldmask = umask (0);
	fail = _mkdir (path);
#else
	mode_t oldmask = umask( (mode_t)0 );
	fail =  mkdir (path, S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP |
	                     S_IWGRP | S_IXGRP | S_IROTH | S_IXOTH );
#endif
	lua_pushboolean (L, fail);
	umask (oldmask);
	return 1;
}


/*
** Directory iterator
*/
static int dir_iter (lua_State *L) {
#ifdef _WIN32
	dir_data *d = (dir_data *)lua_touserdata (L, lua_upvalueindex (1));
	struct _finddata_t c_file;
	if (d->hFile == 0L) { /* first entry */
		if ((d->hFile = _findfirst (d->pattern, &c_file)) == -1L) {
			lua_pushnil (L);
			lua_pushstring (L, strerror (errno));
			return 2;
		} else {
			lua_pushstring (L, c_file.name);
			return 1;
		}
	} else { /* next entry */
		if (_findnext (d->hFile, &c_file) == -1L)
			return 0;
		else {
			lua_pushstring (L, c_file.name);
			return 1;
		}
	}
#else
	DIR *d = *(DIR **) lua_touserdata (L, lua_upvalueindex (1));
	struct dirent *entry;
	if ((entry = readdir (d)) != NULL) {
		lua_pushstring (L, entry->d_name);
		return 1;
	}
	else
		return 0;
#endif
}


/*
** Closes directory iterators
*/
static int dir_close (lua_State *L) {
#ifdef _WIN32
	dir_data *d = (dir_data *)lua_touserdata (L, 1);
	if (d->hFile) {
		_findclose (d->hFile);
	}
#else
	DIR *d = *(DIR **)lua_touserdata (L, 1);
	if (d)
		closedir (d);
#endif
	return 0;
}


/*
** Factory of directory iterators
*/
static int dir_iter_factory (lua_State *L) {
	const char *path = luaL_checkstring (L, 1);
#ifdef _WIN32
	dir_data *dir = (dir_data *) lua_newuserdata (L, sizeof(dir_data));
	dir->hFile = 0L;
	if (strlen(path) > MAX_DIR_LENGTH)
		luaL_error (L, "path too long: %s", path);
	else
		sprintf (dir->pattern, "%s/*", path);
	luaL_getmetatable (L, DIR_METATABLE);
	lua_setmetatable (L, -2);
#else
	DIR **d = (DIR **) lua_newuserdata (L, sizeof(DIR *));
	luaL_getmetatable (L, DIR_METATABLE);
	lua_setmetatable (L, -2);
	*d = opendir (path);
	if (*d == NULL)
		luaL_error (L, "cannot open %s: %s", path, strerror (errno));
#endif
	lua_pushcclosure (L, dir_iter, 1);
	return 1;
}


/*
** Creates directory metatable.
*/
static int dir_create_meta (lua_State *L) {
	luaL_newmetatable (L, DIR_METATABLE);
	/* set its __gc field */
	lua_pushstring (L, "__gc");
	lua_pushcfunction (L, dir_close);
	lua_settable (L, -3);

	return 1;
}


static const struct luaL_reg fslib[] = {
	{"chdir", change_dir},
	{"currentdir", get_dir},
	{"dir", dir_iter_factory},
	{"lock", file_lock},
	{"mkdir", make_dir},
	{"unlock", file_unlock},
	{NULL, NULL},
};

int luaopen_luafilesystem (lua_State *L) {
	dir_create_meta (L);
	luaL_openlib (L, "luafilesystem", fslib, 0);
	return 1;
}