6.5. 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,shm},etc/opt,home,lib,mnt,proc} 
mkdir -p /{root,sbin,tmp,usr/local,var,opt}
for dirname in /usr /usr/local
    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}
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}}

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.

6.5.1. FHS compliance note

We have based our directory tree on the FHS standard (available at http://www.pathname.com/fhs/). Besides the above created tree this standard stipulates the existence of /usr/local/games and /usr/share/games, but we don't much like these for a base system. However, feel free to make your system FHS-compliant. As to the structure of the /usr/local/share subdirectory, the FHS isn't precise, so we created here the directories that we think are needed.