file permissions
file permissions r: 4 w: 2 x: 1 Read, write and execute (full) permission on a file in octal is 0+r+w+x = 0+4+2+1 = 7 Only Read and write permission on a file in octal is 0+r+w+x = 0+4+2+0 = 6 Only read and execute permission on a file in octal is 0+r+w+x = 0+4+0+1 = 5 Use above method to calculate permission for group and others. Let us say you wish to give full permission to owner, read & execute permission to group, and read only permission to others, then you need to calculate permission as follows: User = r+w+x = 0+4+2+1 = 7 Group= r+w+x = 0+4+2+0 = 6 Others = r+w+x = 0+0+0+1 = 1 ...