Chương 4: Làm việc với các tập tin Các lệnh liên quan để thay đổi bài tập nhóm và mật khẩu bao gồm newgrp và gpasswd, cũng như các tập tin / etc / gshadow. Vượt qua các hệ thống tập tin Các lệnh cơ bản để thay đổi thư mục (CD), kiểm tra thư mục hiện hành (pwd) và liệt kê nội dung thư mục (ls) cũng được biết đến cho người sử dụng vỏ thậm chí thường. | Chapter 4 Working with Files Related commands for changing group assignments and passwords include newgrp and gpasswd as well as the etc gshadow file. Traversing the File System Basic commands for changing directories cd checking the current directory pwd and listing directory contents Is are well known to even casual shell users. So this section focuses on some less-common options to those commands as well as other lesser-known features for moving around the file system. Here are some quick examples of cd for moving around the file system cd Change to your home directory cd HOME Change to your home directory cd Change to your home directory cd francois Change to francois home directory cd - Change to previous working directory cd OLDPWD Change to previous working directory cd public_html Change to public_html in your home directory cd . Change to parent of current directory cd usr bin Change to usr bin from root directory cd usr bin Change to usr bin beneath current directory If you want to find out what your current directory is use pwd print working directory pwd home francois Creating symbolic links is a way to access a file from other parts of the file system see the section Using Symbolic and Hard Links earlier in the chapter for more information on symbolic and hard links . However symbolic links can cause some confusion about how parent directories are viewed. The following commands create a symbolic link to the tmp directory from your home directory and show how to tell where you are related to a linked directory cd HOME ln -s tmp tmp-link ls -l tmp-link lrwxrwxrwx 1 francois francois 13 Mar 24 12 41 tmp-link - tmp cd tmp-link pwd home francois tmp-link pwd -P tmp pwd -L home francois tmp-link cd -L . pwd home francois cd tmp-link 77 Chapter 4 Working with Files cd -P . pwd Using the -P and -L options to pwd and cd you can work with symbolically linked directories In their permanent or link locations respectively. For example cd -L . takes you up one level
