Creating directories

Let's now create some structure in our LFS file system. Let's create a directory tree. Issuing the following commands will create a more or less standard tree:

mkdir -p /{bin,boot,dev/pts,etc/opt,home,lib,mnt,proc} && mkdir -p /{root,sbin,tmp,usr/local,var,opt} && for dirname in /usr /usr/local ����do ����mkdir $dirname/{bin,etc,include,lib,sbin,share,src} ����ln -s share/{man,doc,info} $dirname ����mkdir $dirname/share/{dict,doc,info,locale,man} ����mkdir $dirname/share/{nls,misc,terminfo,zoneinfo} ����mkdir $dirname/share/man/man{1,2,3,4,5,6,7,8} done && mkdir /usr/lib/locale && mkdir /var/{lock,log,mail,run,spool} && mkdir -p /var/{tmp,opt,cache,lib/misc,local} && mkdir /opt/{bin,doc,include,info} && mkdir -p /opt/{lib,man/man{1,2,3,4,5,6,7,8}} && ln -s ../var/tmp /usr

Directories are, by default, created with permission mode 755, but this isn't desirable for all directories. We will make two changes: one to the home directory of root, and another to the directories for temporary files.

chmod 0750 /root && chmod 1777 /tmp /var/tmp

The first mode change ensures that not just anybody can enter the /root directory -- the same as a normal user would do with his or her home directory. The second mode change makes sure that any user can write to the /tmp and /var/tmp directories, but cannot remove other users' files from them. The latter is prohibited by the so-called "sticky bit" -- the highest bit in the 1777 bit mask.