This does not take into account sticky or setuid bits. ------------------------------------------------------------- | Owner | ------------------------------------------------------------- | permisions | Umask | ------------------------------------------------------------- | rwxrwxrwx = 777 = 111111111 | --------- = 000 = 000000000 | | rw-rwxrwx = 677 = 110111111 | --x------ = 100 = 001000000 | | r-xrwxrwx = 577 = 101111111 | -w------- = 200 = 010000000 | | r--rwxrwx = 477 = 100111111 | -wx------ = 300 = 011000000 | | -wxrwxrwx = 377 = 011111111 | r-------- = 400 = 100000000 | | -w-rwxrwx = 277 = 010111111 | r-x------ = 500 = 101000000 | | --xrwxrwx = 177 = 001111111 | rw------- = 600 = 110000000 | | ---rwxrwx = 077 = 000111111 | rwx------ = 700 = 111000000 | ------------------------------------------------------------- ------------------------------------------------------------- | Group | ------------------------------------------------------------- | permisions | Umask | ------------------------------------------------------------- | rwxrwxrwx = 777 = 111111111 | --------- = 000 = 000000000 | | rwxrw-rwx = 767 = 111110111 | -----x--- = 010 = 000001000 | | rwxr-xrwx = 757 = 111101111 | ----w---- = 020 = 000010000 | | rwxr--rwx = 747 = 111100111 | ----wx--- = 030 = 000011000 | | rwx-wxrwx = 737 = 111011111 | ---r----- = 040 = 000100000 | | rwx-w-rwx = 727 = 111010111 | ---r-x--- = 050 = 000101000 | | rwx--xrwx = 717 = 111001111 | ---rw---- = 060 = 000110000 | | rwx---rwx = 707 = 111000111 | ---rwx--- = 070 = 000111000 | ------------------------------------------------------------- ------------------------------------------------------------- | Other | ------------------------------------------------------------- | permisions | Umask | ------------------------------------------------------------- | rwxrwxrwx = 777 = 111111111 | --------- = 000 = 000000000 | | rwxrwxrw- = 776 = 111111110 | --------x = 001 = 000000001 | | rwxrwxr-x = 775 = 111111101 | -------w- = 002 = 000000010 | | rwxrwxr-- = 774 = 111111100 | -------wx = 003 = 000000011 | | rwxrwx-wx = 773 = 111111011 | ------r-- = 004 = 000000100 | | rwxrwx-w- = 772 = 111111010 | ------r-x = 005 = 000000101 | | rwxrwx--x = 771 = 111111001 | ------rw- = 006 = 000000110 | | rwxrwx--- = 770 = 111111000 | ------rwx = 007 = 000000111 | ------------------------------------------------------------- ------------------------------------------------------------- | Examples | ------------------------------------------------------------- | permisions | Umask | ------------------------------------------------------------- | rwxr-xr-x = 755 = 111101101 | ----w--w- = 022 = 000010010 | <-- default in most distros | rw-r--r-- = 644 = 110100100 | --x-wx-wx = 133 = 001011011 | | rw-rw---- = 660 = 110110000 | --x--xrwx = 117 = 001001111 | | rwxrwxr-x = 775 = 111111101 | -------w- = 002 = 000000010 | ------------------------------------------------------------- One thing to keep in mind - when dealing with permisions, the highest number you can have is 7 and not 777. 777 is actualy 7-7-7. This is where the binary can make a differance: 777 == 1100001001 7-7-7 == 111-111-111 This is because the binary number for 7 is 111 so 777 is actualy 3 sets of "111" 7 7 7 == 111 111 111 Understanding this can save a lot of confusion in the long run. Also of note - There are nine usable bits out of this - that by design - match up with the permision bits. user read 400 100 000 000 r-- --- --- user write 200 010 000 000 -w- --- --- user execute 100 001 000 000 --x --- --- group read 040 000 100 000 --- r-- --- group write 020 000 010 000 --- -w- --- group execute 010 000 001 000 --- --x --- other read 004 000 000 100 --- --- r-- other write 002 000 000 010 --- --- -w- other execute 001 000 000 001 --- --- --x A 1 turns on a permision, while a 0 turns it off. To see what your current umask is try "umask" and "umask -S" in a shell. You can also use the umask to specify a new umask with an octal umask like this: "umask 022"