/etc/skel的作用

The /etc/skel directory contains files and directories that are automatically copied over to a new user's home directory when such user is created by the useradd program.

A home directory, also called a login directory, is the directory on Unix-like operating systems that serves as the repository for a user's personal files, directories and programs, including personal configuration files. It is also the directory that a user is first in after logging into the system. The /etc directory and its subdirectories contain the many important configuration files for the system.

The useradd program is located in the /usr/sbin/ directory, and on most systems it is accessible only by the root (i.e., administrative) user. On some systems this program might be called adduser.

/etc/skel allows a system administrator to create a default home directory for all new users on a computer or network and thus to make certain that all users begin with the same settings or environment.

Several user configuration files are placed in /etc/skel by default when the operating system is installed. Typically they might include .bash_profile, .bashrc, .bash_logout, dircolors, .inputrc and .vimrc. The dots preceding the names of these files indicate that they are hidden files, i.e., files that are not normally visible in order to avoid visual clutter and help reduce the chances of accidental damage.

The contents of /etc/skel can be viewed by using the ls (i.e., list) command with its -a option (which shows all files and directories, including hidden ones), i.e.,

ls -a /etc/skel

The location of /etc/skel can be changed by editing the line that begins with SKEL= in the configuration file /etc/default/useradd. By default this line says SKEL=/etc/skel.

It is usually better to keep /etc/skel as small as possible and put system-wide configuration items into global configuration files such as /etc/profile. This is because the latter makes it much easier to update existing users' files because its settings take effect as soon as the system is turned on and apply to new users and old uses alike.

When a user is removed from the system by an administrator with the userdel command, that user's home directory, including the files and directories that have been copied into it from /etc/skel, remains intact.

The name of the directory skel is derived from the word skeleton, because the files it contains form the basic structure for users' home directories.