Lua 5.1 compatibility

It returns the resolved path of the symlink.

doc/us/manual.html

@@ -104,7 +104,7 @@ LuaFileSystem offers the following functions:
 <dl class="reference">
     <dt><a name="attributes"></a><strong><code>lfs.attributes (filepath [, aname | atable])</code></strong></dt>
     <dd>Returns a table with the file attributes corresponding to
-    <code>filepath</code> (or <code>nil</code> followed by an error message and a system-dependent error code
+    <code>filepath</code> (or <code>nil</code> followed by an error message
     in case of error).
     If the second optional argument is given and is a string, then only the value of the
     named attribute is returned (this use is equivalent to
@@ -177,7 +177,7 @@ LuaFileSystem offers the following functions:
     Returns <code>true</code> in case of success or <code>nil</code> plus an
     error string.</dd>
 
-    <dt><a name="lock_dir"></a><strong><code>lfs.lock_dir(path, [seconds_stale])</code></strong></dt>
+    <dt><a name="chdir"></a><strong><code>lfs.lock_dir(path, [seconds_stale])</code></strong></dt>
     <dd>Creates a lockfile (called lockfile.lfs) in <code>path</code> if it does not
   exist and returns the lock. If the lock already exists checks if
   it's stale, using the second parameter (default for the second
@@ -187,7 +187,7 @@ LuaFileSystem offers the following functions:
   particular, if the lock exists and is not stale it returns the
   "File exists" message.</dd>
         
-    <dt><a name="currentdir"></a><strong><code>lfs.currentdir ()</code></strong></dt>
+    <dt><a name="getcwd"></a><strong><code>lfs.currentdir ()</code></strong></dt>
     <dd>Returns a string with the current working directory or <code>nil</code>
     plus an error string.</dd>
     
@@ -222,14 +222,14 @@ LuaFileSystem offers the following functions:
     <dt><a name="mkdir"></a><strong><code>lfs.mkdir (dirname)</code></strong></dt>
     <dd>Creates a new directory. The argument is the name of the new
     directory.<br />
-    Returns <code>true</code> in case of success or <code>nil</code>, an error message and
-    a system-dependent error code in case of error.
+    Returns <code>true</code> if the operation was successful;
+    in case of error, it returns <code>nil</code> plus an error string.
     </dd>
     
     <dt><a name="rmdir"></a><strong><code>lfs.rmdir (dirname)</code></strong></dt>
     <dd>Removes an existing directory. The argument is the name of the directory.<br />
-    Returns <code>true</code> in case of success or <code>nil</code>, an error message and
-    a system-dependent error code in case of error.
+    Returns <code>true</code> if the operation was successful;
+    in case of error, it returns <code>nil</code> plus an error string.</dd>
 
     <dt><a name="setmode"></a><strong><code>lfs.setmode (file, mode)</code></strong></dt>
     <dd>Sets the writing mode for a file. The mode string can be either <code>"binary"</code> or <code>"text"</code>.
@@ -257,8 +257,8 @@ LuaFileSystem offers the following functions:
     Lua standard function <code>os.time</code>).
     If the modification time is omitted, the access time provided is used;
     if both times are omitted, the current time is used.<br />
-    Returns <code>true</code> in case of success or <code>nil</code>, an error message and
-    a system-dependent error code in case of error.
+    Returns <code>true</code> if the operation was successful;
+    in case of error, it returns <code>nil</code> plus an error string.
     </dd>
     
     <dt><a name="unlock"></a><strong><code>lfs.unlock (filehandle[, start[, length]])</code></strong></dt>

src/lfs.c

@@ -41,26 +41,22 @@
 #include <sys/stat.h>
 
 #ifdef _WIN32
-  #include <direct.h>
-  #include <windows.h>
-  #include <io.h>
-  #include <sys/locking.h>
-  #ifdef __BORLANDC__
-    #include <utime.h>
-  #else
-    #include <sys/utime.h>
-  #endif
-  #include <fcntl.h>
-  /* MAX_PATH seems to be 260. Seems kind of small. Is there a better one? */
-  #define LFS_MAXPATHLEN MAX_PATH
+#include <direct.h>
+#include <windows.h>
+#include <io.h>
+#include <sys/locking.h>
+#ifdef __BORLANDC__
+ #include <utime.h>
 #else
-  #include <unistd.h>
-  #include <dirent.h>
-  #include <fcntl.h>
-  #include <sys/types.h>
-  #include <utime.h>
-  #include <sys/param.h> /* for MAXPATHLEN */
-  #define LFS_MAXPATHLEN MAXPATHLEN
+ #include <sys/utime.h>
+#endif
+#include <fcntl.h>
+#else
+#include <unistd.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <utime.h>
 #endif
 
 #include <lua.h>
@@ -89,6 +85,22 @@
 #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)
+  #ifdef _WIN32
+	 /* MAX_PATH seems to be 260. Seems kind of small. Is there a better one? */
+    #define LFS_MAXPATHLEN MAX_PATH
+  #else
+	/* For MAXPATHLEN: */
+    #include <sys/param.h>
+    #define LFS_MAXPATHLEN MAXPATHLEN
+  #endif
+#endif
+
 #define DIR_METATABLE "directory metatable"
 typedef struct dir_data {
         int  closed;
@@ -121,13 +133,6 @@ typedef struct dir_data {
 #define LSTAT_FUNC lstat
 #endif
 
-#ifdef _WIN32
-  #define lfs_mkdir _mkdir
-#else
-  #define lfs_mkdir(path) (mkdir((path), \
-    S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IWGRP | S_IXGRP | S_IROTH | S_IXOTH))
-#endif
-
 /*
 ** Utility functions
 */
@@ -142,13 +147,12 @@ static int pusherror(lua_State *L, const char *info)
         return 3;
 }
 
-static int pushresult(lua_State *L, int res, const char *info) {
-  if (res == -1) {
-    return pusherror(L, info);
-  } else {
-    lua_pushboolean(L, 1);
-    return 1;
-  }
+static int pushresult(lua_State *L, int i, const char *info)
+{
+        if (i==-1)
+                return pusherror(L, info);
+        lua_pushinteger(L, i);
+        return 1;
 }
 
 
@@ -174,35 +178,18 @@ static int change_dir (lua_State *L) {
 **  and a string describing the error
 */
 static int get_dir (lua_State *L) {
-#ifdef NO_GETCWD
+  char *path;
+  /* Passing (NULL, 0) is not guaranteed to work. Use a temp buffer and size instead. */
+  char buf[LFS_MAXPATHLEN];
+  if ((path = getcwd(buf, LFS_MAXPATHLEN)) == NULL) {
     lua_pushnil(L);
-    lua_pushstring(L, "Function 'getcwd' not provided by system");
+    lua_pushstring(L, getcwd_error);
     return 2;
-#else
-    char *path = NULL;
-    /* Passing (NULL, 0) is not guaranteed to work. Use a temp buffer and size instead. */
-    size_t size = LFS_MAXPATHLEN; /* initial buffer size */
-    int result;
-    while (1) {
-        path = realloc(path, size);
-        if (!path) /* failed to allocate */
-            return pusherror(L, "get_dir realloc() failed");
-        if (getcwd(path, size) != NULL) {
-            /* success, push the path to the Lua stack */
-            lua_pushstring(L, path);
-            result = 1;
-            break;
-        }
-        if (errno != ERANGE) { /* unexpected error */
-            result = pusherror(L, "get_dir getcwd() failed");
-            break;
-        }
-        /* ERANGE = insufficient buffer capacity, double size and retry */
-        size *= 2;
-    }
-    free(path);
-    return result;
-#endif
+  }
+  else {
+    lua_pushstring(L, path);
+    return 1;
+  }
 }
 
 /*
@@ -430,20 +417,16 @@ static int file_unlock (lua_State *L) {
 ** @param #2 Name of link.
 ** @param #3 True if link is symbolic (optional).
 */
-static int make_link (lua_State *L) {
+static int make_link(lua_State *L)
+{
 #ifndef _WIN32
-  const char *oldpath = luaL_checkstring(L, 1);
-  const char *newpath = luaL_checkstring(L, 2);
-  int res = (lua_toboolean(L,3) ? symlink : link)(oldpath, newpath);
-  if (res == -1) {
-    return pusherror(L, NULL);
-  } else {
-    lua_pushinteger(L, 0);
-    return 1;
-  }
+        const char *oldpath = luaL_checkstring(L, 1);
+        const char *newpath = luaL_checkstring(L, 2);
+        return pushresult(L,
+                (lua_toboolean(L,3) ? symlink : link)(oldpath, newpath), NULL);
 #else
-  errno = ENOSYS; /* = "Function not implemented" */
-  return pushresult(L, -1, "make_link is not supported on Windows");
+        errno = ENOSYS; /* = "Function not implemented" */
+        return pushresult(L, -1, "make_link is not supported on Windows");
 #endif
 }
 
@@ -453,8 +436,21 @@ static int make_link (lua_State *L) {
 ** @param #1 Directory path.
 */
 static int make_dir (lua_State *L) {
-  const char *path = luaL_checkstring(L, 1);
-  return pushresult(L, lfs_mkdir(path), NULL);
+        const char *path = luaL_checkstring (L, 1);
+        int fail;
+#ifdef _WIN32
+        fail = _mkdir (path);
+#else
+        fail =  mkdir (path, S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP |
+                             S_IWGRP | S_IXGRP | S_IROTH | S_IXOTH );
+#endif
+        if (fail) {
+                lua_pushnil (L);
+        lua_pushfstring (L, "%s", strerror(errno));
+                return 2;
+        }
+        lua_pushboolean (L, 1);
+        return 1;
 }
 
 
@@ -463,8 +459,18 @@ static int make_dir (lua_State *L) {
 ** @param #1 Directory path.
 */
 static int remove_dir (lua_State *L) {
-  const char *path = luaL_checkstring(L, 1);
-  return pushresult(L, rmdir(path), NULL);
+        const char *path = luaL_checkstring (L, 1);
+        int fail;
+
+        fail = rmdir (path);
+
+        if (fail) {
+                lua_pushnil (L);
+                lua_pushfstring (L, "%s", strerror(errno));
+                return 2;
+        }
+        lua_pushboolean (L, 1);
+        return 1;
 }
 
 
@@ -651,24 +657,26 @@ static const char *mode2string (mode_t mode) {
 
 
 /*
-** Set access time and modification values for a file.
-** @param #1 File path.
-** @param #2 Access time in seconds, current time is used if missing.
-** @param #3 Modification time in seconds, access time is used if missing.
+** Set access time and modification values for file
 */
 static int file_utime (lua_State *L) {
-  const char *file = luaL_checkstring(L, 1);
-  struct utimbuf utb, *buf;
+        const char *file = luaL_checkstring (L, 1);
+        struct utimbuf utb, *buf;
 
-  if (lua_gettop (L) == 1) /* set to current date/time */
-    buf = NULL;
-  else {
-    utb.actime = (time_t) luaL_optnumber(L, 2, 0);
-    utb.modtime = (time_t) luaL_optinteger(L, 3, utb.actime);
-    buf = &utb;
-  }
-
-  return pushresult(L, utime(file, buf), NULL);
+        if (lua_gettop (L) == 1) /* set to current date/time */
+                buf = NULL;
+        else {
+                utb.actime = (time_t)luaL_optnumber (L, 2, 0);
+                utb.modtime = (time_t) luaL_optinteger (L, 3, utb.actime);
+                buf = &utb;
+        }
+        if (utime (file, buf)) {
+                lua_pushnil (L);
+                lua_pushfstring (L, "%s", strerror (errno));
+                return 2;
+        }
+        lua_pushboolean (L, 1);
+        return 1;
 }
 
 
@@ -805,8 +813,7 @@ static int _file_info_ (lua_State *L, int (*st)(const char*, STAT_STRUCT*)) {
         if (st(file, &info)) {
                 lua_pushnil(L);
                 lua_pushfstring(L, "cannot obtain information from file '%s': %s", file, strerror(errno));
-                lua_pushinteger(L, errno);
-                return 3;
+                return 2;
         }
         if (lua_isstring (L, 2)) {
                 const char *member = lua_tostring (L, 2);
@@ -820,8 +827,7 @@ static int _file_info_ (lua_State *L, int (*st)(const char*, STAT_STRUCT*)) {
                 /* member not found */
                 return luaL_error(L, "invalid attribute name '%s'", member);
         }
-        /* creates a table if none is given, removes extra arguments */
-        lua_settop(L, 2);
+        /* creates a table if none is given */
         if (!lua_istable (L, 2)) {
                 lua_newtable (L);
         }
@@ -855,21 +861,37 @@ static int push_link_target(lua_State *L) {
         return 0;
 #else
         const char *file = luaL_checkstring(L, 1);
-        char *target = NULL;
-        int tsize, size = 256; /* size = initial buffer capacity */
-        while (1) {
-            target = realloc(target, size);
-            if (!target) /* failed to allocate */
+        char *target;
+        int size, tsize;
+        if (lua_type(L, -1) == LUA_TTABLE) {
+                /* when symlinkattributes collects the whole table,
+                   get the size from it */
+                lua_getfield(L, -1, "size");
+                int size_type = lua_type(L, -1);
+                if (size_type != LUA_TNUMBER) {
+                        lua_pop(L, 1);
+                        errno = EINVAL;
+                        return 0;
+                }
+                size = lua_tointeger(L, -1);
+                lua_pop(L, 1);
+        } else {
+                /* when we are just getting 'target', we need to run
+                   lstat ourselves to get the size */
+                STAT_STRUCT info;
+                if (LSTAT_FUNC(file, &info)) {
+                        return 0;
+                }
+                size = info.st_size;
+        }
+        target = (char*) malloc(size + 1);
+        if (!target) {
                 return 0;
-            tsize = readlink(file, target, size);
-            if (tsize < 0) { /* a readlink() error occurred */
+        }
+        tsize = readlink(file, target, size);
+        if (tsize != size) {
                 free(target);
                 return 0;
-            }
-            if (tsize < size)
-                break;
-            /* possibly truncated readlink() result, double size and retry */
-            size *= 2;
         }
         target[tsize] = '\0';
         lua_pushlstring(L, target, tsize);

tests/test.lua

@@ -132,17 +132,6 @@ for key, value in pairs(attr) do
           "lfs.attributes values not consistent")
 end
 
--- Check that lfs.attributes accepts a table as second argument
-local attr2 = {}
-lfs.attributes(tmpfile, attr2)
-for key, value in pairs(attr2) do
-  assert (value == lfs.attributes (tmpfile, key),
-          "lfs.attributes values with table argument not consistent")
-end
-
--- Check that extra arguments are ignored
-lfs.attributes(tmpfile, attr2, nil)
-
 -- Remove new file and directory
 assert (os.remove (tmpfile), "could not remove new file")
 assert (lfs.rmdir (tmpdir), "could not remove new directory")
@@ -152,10 +141,7 @@ io.write(".")
 io.flush()
 
 -- Trying to get attributes of a non-existent file
-local attr_ok, err, errno = lfs.attributes("this couldn't be an actual file")
-assert(attr_ok == nil, "could get attributes of a non-existent file")
-assert(type(err) == "string", "failed lfs.attributes did not return an error message")
-assert(type(errno) == "number", "failed lfs.attributes did not return error code")
+assert (lfs.attributes ("this couldn't be an actual file") == nil, "could get attributes of a non-existent file")
 assert (type(lfs.attributes (upper)) == "table", "couldn't get attributes of upper directory")
 
 io.write(".")