Bug #652: Wrong results and sideeffects of filetype()

From: fritz@wuemaus.franken.de Operating system: Any (tested only on Linux) PHP version: 3.0.2a PHP Bug Type: Misbehaving function Bug description: I just found a bug in functions/filestat.c which causes two types of wrong behavior when using the filetype() function: a) The type of a symlink is only returned correctly, if the link points to a regular file. In real life, symlinks can point to anything. b) (even worse). Calling filetype() overwrites the permisssions in the global stat cache (IMHO _unwanted_ side-effect). EXAMPLE: Situation in real life: ls -l /tmp lrwxrwxrwx 1 root root 4 Aug 13 16:58 dusel -> /usr -rw-r--r-- 1 root root 0 May 4 00:53 mysqlaccess.log lrwxrwxrwx 1 root root 15 Aug 13 16:57 wusel -> mysqlaccess.log Script: clearstatcache(); echo filetype("/tmp/dusel") . "<BR>\n"; echo sprintf("%08o", fileperms("/tmp/wusel")) . "<BR>\n"; echo filetype("/tmp/wusel") . "<BR>\n"; echo sprintf("%08o", fileperms("/tmp/wusel")) . "<BR>\n"; Result: dir 00100644 link 00120777 FIX: The reason for the above behaviour is in functions/filestat.c, where a) lstat() is called only for regular files. b) when calling lstat(), a GLOBAL stbuf is used. The following patch solves both problems by a) calling lstat() unconditionally. b) using a local struct stbuf. --- functions/filestat.c.orig Thu Aug 13 17:22:17 1998 +++ functions/filestat.c Thu Aug 13 17:29:10 1998 @@ -429,6 +429,12 @@ RETURN_LONG((long)GLOBAL(sb).st_ctime); break; case 8: /* filetype */ + { + struct stat lsb; + lstat(GLOBAL(CurrentStatFile),&lsb); + if ((lsb.st_mode&S_IFMT) == S_IFLNK) { + RETURN_STRING("link",1); + } switch(GLOBAL(sb).st_mode&S_IFMT) { case S_IFIFO: RETURN_STRING("fifo",1); @@ -443,17 +449,13 @@ RETURN_STRING("block",1); break; case S_IFREG: - lstat(GLOBAL(CurrentStatFile),&GLOBAL(sb)); - if ((GLOBAL(sb).st_mode&S_IFMT) == S_IFLNK) { - RETURN_STRING("link",1); - } else { RETURN_STRING("file",1); - } break; default: php3_error(E_WARNING,"Unknown file type (%d)",GLOBAL(sb).st_mode&S_IF MT); RETURN_STRING("unknown",1); break; + } } break; case 9: /*is writable*/ -- PHP Development Mailing List http://www.php.net/ To unsubscribe send an empty message to php-dev-unsubscribe@lists.php.net For help: php-dev-help@lists.php.net