On Thursday 08 February 2007 09:29, edwardspl@xxxxxxxxxx wrote: > Les Mikesell wrote: > >edwardspl@xxxxxxxxxx wrote: > >>>>chmod g+rwx ( What number of g+rwx, eg : ?77 ) > >>>> /home/edward > >>> > >>>You can use the symbolic form literally. I think it's > >>> easier to understand. Let the computer do the > >>> binary/octal math. g+rwx means add the read, write, > >>> and execute bits for the group. > >> > >>But I want to know what no of g+rwx... > > > >The + means it is added to the bits already permitted. > > Look at them as groups of 3 bits in binary and take the > > octal value. > > > > user group other > > rwx rwx rwx > > > >You'll start with a home dir having rwx --- --- so > > that's 111 000 000 binary or 700 octal. > >Add the group rwx and you get 111 111 000 or 770 octal > > So, g+rwx = 770, right ? > > >>>>chmod +t ( What number of +t ) /home/edward > > > >That's one more bit to the left, 1 000 000 000 binary, > > so 1000 octal. Add that to what you have. > > > >>>Same here, you can type it that way and it means add > >>> the "sticky" bit. > >> > >>Also want to know... > > > >Altogether, the octal value for the mode ends up at > > 1770. But, as I said before the computer does a better > > job of thinking in octal. > > So, +t = 1770, right ? > > Edward. When I first started learning how to write the permissions setting RWX I could not figure out how to do it using the letters. I found it very easy to understand doing it with the numbers. I type it like this chmod 777 <file> to get the rwxrwxrwx and if I want to change it to rwxr-xr-x I just type chmod 755 <file> and if I want rwx------ I type chmod 700 <file>. I am sure I can figure out how to write it with the letters now but I think it is much easier to use the numbers.
