diff --git a/doc/us/manual.html b/doc/us/manual.html index beffe03..3555e3d 100644 --- a/doc/us/manual.html +++ b/doc/us/manual.html @@ -177,7 +177,7 @@ LuaFileSystem offers the following functions: Returns true in case of success or nil plus an error string. -
lfs.lock_dir(path, [seconds_stale])
+
lfs.lock_dir(path, [seconds_stale])
Creates a lockfile (called lockfile.lfs) in path 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.
-
lfs.currentdir ()
+
lfs.currentdir ()
Returns a string with the current working directory or nil plus an error string.
@@ -242,6 +242,8 @@ LuaFileSystem offers the following functions:
lfs.symlinkattributes (filepath [, aname])
Identical to lfs.attributes except that it obtains information about the link itself (not the file it refers to). + It also adds a target field, containing + the file name that the symlink points to. On Windows this function does not yet support links, and is identical to lfs.attributes.
diff --git a/src/lfs.c b/src/lfs.c index dd0b6af..aeaa8b4 100644 --- a/src/lfs.c +++ b/src/lfs.c @@ -41,22 +41,26 @@ #include #ifdef _WIN32 -#include -#include -#include -#include -#ifdef __BORLANDC__ - #include + #include + #include + #include + #include + #ifdef __BORLANDC__ + #include + #else + #include + #endif + #include + /* MAX_PATH seems to be 260. Seems kind of small. Is there a better one? */ + #define LFS_MAXPATHLEN MAX_PATH #else - #include -#endif -#include -#else -#include -#include -#include -#include -#include + #include + #include + #include + #include + #include + #include /* for MAXPATHLEN */ + #define LFS_MAXPATHLEN MAXPATHLEN #endif #include @@ -85,22 +89,6 @@ #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 - #define LFS_MAXPATHLEN MAXPATHLEN - #endif -#endif - #define DIR_METATABLE "directory metatable" typedef struct dir_data { int closed; @@ -186,18 +174,35 @@ static int change_dir (lua_State *L) { ** and a string describing the error */ static int get_dir (lua_State *L) { - 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) { +#ifdef NO_GETCWD lua_pushnil(L); - lua_pushstring(L, getcwd_error); + lua_pushstring(L, "Function 'getcwd' not provided by system"); return 2; - } - else { - lua_pushstring(L, path); - return 1; - } +#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 } /* @@ -815,7 +820,8 @@ 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 */ + /* creates a table if none is given, removes extra arguments */ + lua_settop(L, 2); if (!lua_istable (L, 2)) { lua_newtable (L); } @@ -837,11 +843,58 @@ static int file_info (lua_State *L) { } +/* +** Push the symlink target to the top of the stack. +** Assumes the file name is at position 1 of the stack. +** Returns 1 if successful (with the target on top of the stack), +** 0 on failure (with stack unchanged, and errno set). +*/ +static int push_link_target(lua_State *L) { +#ifdef _WIN32 + errno = ENOSYS; + 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 */ + return 0; + tsize = readlink(file, target, size); + if (tsize < 0) { /* a readlink() error occurred */ + 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); + free(target); + return 1; +#endif +} + /* ** Get symbolic link information using lstat. */ static int link_info (lua_State *L) { - return _file_info_ (L, LSTAT_FUNC); + int ret; + if (lua_isstring (L, 2) && (strcmp(lua_tostring(L, 2), "target") == 0)) { + int ok = push_link_target(L); + return ok ? 1 : pusherror(L, "could not obtain link target"); + } + ret = _file_info_ (L, LSTAT_FUNC); + if (ret == 1 && lua_type(L, -1) == LUA_TTABLE) { + int ok = push_link_target(L); + if (ok) { + lua_setfield(L, -2, "target"); + } + } + return ret; } diff --git a/tests/test.lua b/tests/test.lua index 193e0bd..591ee25 100644 --- a/tests/test.lua +++ b/tests/test.lua @@ -91,6 +91,8 @@ io.flush() if lfs.link (tmpfile, "_a_link_for_test_", true) then assert (lfs.attributes"_a_link_for_test_".mode == "file") assert (lfs.symlinkattributes"_a_link_for_test_".mode == "link") + assert (lfs.symlinkattributes"_a_link_for_test_".target == tmpfile) + assert (lfs.symlinkattributes("_a_link_for_test_", "target") == tmpfile) assert (lfs.link (tmpfile, "_a_hard_link_for_test_")) assert (lfs.attributes (tmpfile, "nlink") == 2) assert (os.remove"_a_link_for_test_") @@ -130,6 +132,17 @@ 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")