000 -> 0
001 -> 1
010 -> 2
011 -> 3
100 -> 4
101 -> 5
110 -> 6
111 -> 7
-------------------------------------
x is able to excute
w is able to write
r is able to read
for example :
-(rwx)(r-x)(r-x) 1 kei pcad 22 11月 17 10:28 00.sshlx95.sh
( 1 )( 2 )( 3 ) owner group filename
-> (1):the owner (2):the owner's group (3):the others
now
the owner : read,write,excute
the owner's group : read, no write, excute
the others : read , no write , excute