Tham khảo tài liệu 'learning debiangnu linux-chapter 13. conquering the bash shell', công nghệ thông tin, hệ điều hành phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 13. Conquering the BASH Shell This chapter describes the powerful BASH shell providing a much more detailed explanation than that provided in Chapter 4 Issuing Linux Commands. The chapter also briefly explains shell variables shell scripts and shell aliases preparing you for an in-depth continuing study of Linux. The Linux Shell You met the Linux command interpreter or shell early in this book. Like an MS-DOS Prompt window the shell lets you issue commands that it interprets or executes. By means of the shell you use and control your system. A Variety of Shells The MS-DOS shell has been fairly consistent over time for example the differences between MS-DOS v3 and MS-DOS v7 are few. The Unix shell however has experienced significantly more evolutionary development than MS-DOS. Today you find both versions and variants of the Unix shell. The Unix shell variants have much in common but each has a different authorship and history and each reflects a different view of how users should interact with Unix. Linux includes the most popular Unix shells as shown in Table . The most popular Linux shell is the BASH shell the Bourne Again SHell based on the original Unix Bourne shell. The BASH shell is largely compliant with the POSIX standard which specifies the syntax and operation of a standard Unix shell and which has been widely implemented. Because of the popularity of the POSIX standard and the obvious advantage of working with a shell that s consistent across a variety of computing platforms this chapter focuses on the BASH shell. Most Linux systems are configured to automatically start a BASH shell on your behalf when you log in so you don t generally need to be much concerned about choosing a shell. However for information about the other available shells you can consult the Linux man pages. Table Common Linux Shells Shell name Program name s Description ASH shell bin ash bin bsh Resembles the shell used by AT T s System V Unix. BASH shell bin bash
