Different Shells

HP-UX, like all UNIX variants, allows you to select among different shells. A lot of material is available on the POSIX shell, which is the default HP-UX shell in most cases. There is less information available on the other widely used shells, so I have decided to cover them in this chapter. The shell is important to you as a system administrator and user because it is your window into the system. I decided to include the KornShell and C shell in this chapter because so many new HP-UX users and system administrators use them as their shells even though the POSIX shell is the default on most systems. I included Bash because it is widely used in Open Source enviornments and many Open Source GNU tools are available for HP-UX 11i. The upcoming sections cover these three shells. The KornShell section also covers some important topics related to shells such as File Name Expansion, Redirection, Background Jobs, and umask and Permissions. Some of these topics have been covered in other chapters of the book, but these topics are closely related to your shell, so I decided to include them here as well.