-r  File or directory is readable
-w  File or directory is writable
-x  File or directory is executable
-o  File or directory is owned by user
-R  File or directory is readable by real user, not effective user (differs from -r for setuid programs)
-W  File or directory is writable by real user, not effective user (differs from -w for setuid programs)
-X  File or directory is executable by real user, not effective user (differs from -x for setuid programs)
-O  File or directory is owned by real user, not effective user (differs from -o for setuid programs)
-e  File or directory exists
-z  File exists and has zero size (directories are never empty)
-s  File or directory exists and has nonzero size (the value is the size in bytes)
-f  Entry is a plain file
-d  Entry is a directory
-l  Entry is a symlink
-S  Entry is a socket
-p  Entry is a named pipe (a "fifo")
-b  Entry is a block-special file (like a mountable disk)
-c  Entry is a character-special file (like an I/O device)
-u  File or directory is setuid
-g  File or directory is setgid
-k  File or directory has the sticky bit set
-t  isatty() on the filehandle is true
-T  File is "text"
-B  File is "binary"
-M  Modification age in days
-A  Access age in days
-C  Inode-modification age in days