com32/lua/src/lfs.c

   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 */
  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 */
  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 */
  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 */
 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 */
 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 */
 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 */
 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 */
 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 */
 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 */
 214 static void push_st_size (lua_State *L, STAT_STRUCT *info) {
 215         lua_pushnumber (L, (lua_Number)info->st_size);
 216 }
 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 */
 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 */
 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
 292 LUALIB_API int luaopen_lfs (lua_State *L) {
 293   dir_create_meta (L);
 294   luaL_newlib (L, fslib);
 295   return 1;
 296 }