Implemented lfs.chown and lfs.chmod functions

src/lfs.c

@@ -31,6 +31,8 @@
 #include <stdlib.h>
 #include <time.h>
 #include <sys/stat.h>
+#include <pwd.h>
+#include <grp.h>
 
 #ifdef _WIN32
 
@@ -1137,6 +1139,162 @@ static void set_info(lua_State * L)
  lua_setfield(L, -2, "_VERSION");
 }
 
+/*
+** Change file permissions
+** First argument is file, second is permission string
+** Return true or nil + error string
+** On Windows do nothing and return nil
+*/
+static int lfs_chmod(lua_State * L)
+{
+#ifdef _WIN32
+ lua_pushnil(L);
+ lua_pushliteral(L, "Not implemented for Windows");
+ return 1;
+#else
+ if (!lua_isstring(L, 1)) {
+ lua_pushnil(L);
+ lua_pushliteral(L, "Path has to be a string");
+ return 2;
+ }
+ const char *filepath = lua_tostring(L, 1);
+
+ mode_t mode = 0;
+ const char *mode_string;
+ switch (lua_type(L, 2)) {
+ case LUA_TNUMBER:
+ mode = lua_tonumber(L, 2);
+ break;
+ case LUA_TSTRING:
+ mode_string = lua_tostring(L, 2);
+ if (strlen(mode_string) != 9) {
+ lua_pushnil(L);
+ lua_pushliteral(L, "Mode string has to be 9 characters long");
+ return 2;
+ }
+#define check_mode_string(i, c, v) { if (mode_string[i] == c) mode |= v; else if \
+ (mode_string[i] != '-') goto wrong_format; }
+ check_mode_string(0, 'r', S_IRUSR);
+ check_mode_string(1, 'w', S_IWUSR);
+ check_mode_string(2, 'x', S_IXUSR);
+ check_mode_string(3, 'r', S_IRGRP);
+ check_mode_string(4, 'w', S_IWGRP);
+ check_mode_string(5, 'x', S_IXGRP);
+ check_mode_string(6, 'r', S_IROTH);
+ check_mode_string(7, 'w', S_IWOTH);
+ check_mode_string(8, 'x', S_IXOTH);
+ break;
+ wrong_format:
+ lua_pushnil(L);
+ lua_pushliteral(L, "Wrong mode string format");
+ return 2;
+ default:
+ lua_pushnil(L);
+ lua_pushliteral(L, "Mode has to be a string or number");
+ return 2;
+ }
+
+ if (chmod(filepath, mode) != 0) {
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(errno));
+ return 2;
+ }
+
+ lua_pushboolean(L, 1);
+ return 1;
+#endif
+}
+
+/*
+** Change file owner
+** First argument is file, second is uid (optional), third is gid (optional)
+** Return true or nil + error string
+** On Windows do nothing and return nil
+*/
+static int lfs_chown(lua_State * L)
+{
+#ifdef _WIN32
+ lua_pushnil(L);
+ lua_pushliteral(L, "Not implemented for Windows");
+ return 2;
+#else
+ if (!lua_isstring(L, 1)) {
+ lua_pushnil(L);
+ lua_pushliteral(L, "Path has to be a string");
+ return 2;
+ }
+ const char *filepath = lua_tostring(L, 1);
+
+ struct stat fileinfo;
+ if (stat(filepath, &fileinfo) != 0) {
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(errno));
+ return 2;
+ }
+
+ uid_t uid;
+ struct passwd *pswd;
+ const char *username;
+ switch (lua_type(L, 2)) {
+ case LUA_TNIL:
+ uid = fileinfo.st_uid;
+ break;
+ case LUA_TSTRING:
+ username = lua_tostring(L, 2);
+ pswd = getpwnam(username);
+ if (pswd == NULL) {
+ lua_pushnil(L);
+ lua_pushliteral(L, "Failed to get uid");
+ return 2;
+ }
+ uid = pswd->pw_uid;
+ break;
+ case LUA_TNUMBER:
+ uid = (uid_t)lua_tonumber(L, 2);
+ break;
+ default:
+ lua_pushnil(L);
+ lua_pushliteral(L, "Uid has to be a string, number or nil");
+ return 2;
+ }
+
+ gid_t gid;
+ struct group *grp;
+ const char *groupname;
+ switch (lua_type(L, 3)) {
+ case LUA_TNIL:
+ gid = fileinfo.st_gid;
+ break;
+ case LUA_TSTRING:
+ groupname = lua_tostring(L, 3);
+ grp = getgrnam(groupname);
+ if (grp == NULL) {
+ lua_pushnil(L);
+ lua_pushliteral(L, "Failed to get gid");
+ return 2;
+ }
+ gid = grp->gr_gid;
+ break;
+ case LUA_TNUMBER:
+ gid = (gid_t)lua_tonumber(L, 3);
+ break;
+ default:
+ lua_pushnil(L);
+ lua_pushliteral(L, "Gid has to be a string, number or nil");
+ return 2;
+ }
+
+ if (chown(filepath, uid, gid) != 0) {
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(errno));
+ return 2;
+ }
+
+ lua_pushboolean(L, 1);
+ return 1;
+#endif
+}
+
 
 static const struct luaL_Reg fslib[] = {
  { "attributes", file_info },
@@ -1152,6 +1310,8 @@ static const struct luaL_Reg fslib[] = {
  { "touch", file_utime },
  { "unlock", file_unlock },
  { "lock_dir", lfs_lock_dir },
+ { "chmod", lfs_chmod },
+ { "chown", lfs_chown },
  { NULL, NULL },
 };