Pro Bash Programming: Scripting the Linux Shell

Introduction Although most users think of the shell as an interactive command interpreter, it is really a programming language in which each statement runs a command. Because it must satisfy both the interactive and programming aspects of command execution, it is a strange language, shaped as much by history as by design. Brian Kernighan and Rob Pike, The UNIX Programming Environment, Prentice-Hall, 1984 The shell is a programming language. Don't let anyone tell you otherwise. The shell is not just glue that sticks bits together. The shell is a lot more than a tool that runs other tools. The shell is a complete programming language! When a Linux user asked me about membership databases, I asked him what he really needed. He wanted to store names and addresses for a couple of hundred members and print mailing labels for each of them. I recommended using a text editor to store the information in a text file, and I provided a shell script to create the labels in PostScript. (The script, ps-labels, appeared in my first book, Shell Scripting Recipes: A Problem-Solution Approach. ) When the SWEN worm was dumping hundreds of megabytes of junk into my mailbox every few minutes, I wrote a shell script to filter them out on the mail server and download the remaining mail to my home computer. That script has been doing its job for several years.

Author: Chris Johnson
Publisher: Apress
Published: 10/19/2009
Pages: 350
Binding Type: Paperback
Weight: 1lbs
Size: 9.20h x 7.40w x 0.60d
ISBN: 9781430219972

About the Author
Chris F.A. Johnson was introduced to Unix in 1990 and learned shell scripting because there was no C compiler on the system. His first major project was a menu-driven, user-extensible database system with report generator. Chris uses the shell as his primary, general-purpose programming language, and his projects have included a member database, menuing system, and POP3 mail filtering and retrieval. Chris is the author of Shell Scripting Recipes: A Problem-Solution Approach (Apress, 2005). When not pushing shell scripting to the limit, he designs and codes web sites, teaches chess, and composes cryptic crosswords.