Java™ Application Development on Linux - Dator

30Chapter 1An Embarrassment of Riches: The Linux EnvironmentThere are other help systems available, such as info and some GUI-basedones. But man provides some of the quickest and most terse help when youneed to check the syntax of a command or find out if there is an option thatdoes what you need.1.4REVIEWWe’ve looked at commands that will show you where files are in your directorystructure, show files’ permissions and sizes, change the permissions, show youwhat is in a file, look for files by searching for strings, and look for files basedon names or other properties.Even so, we’ve given only the briefest coverage to only a few of the scoresof Linux commands worth knowing. Tops among these is the shell, bash inour case. Whole books have been written on this subject, and you would dowell to have one at hand.1.5WHAT YOU STILL DON’T KNOWThe shell is a powerful language in its own right. While you think of it mostlyas a command interpreter used for running other commands, it is, in fact, alanguage, complete with variables, logic and looping constructs. We are notsuggesting that you write your application in shell scripts, but you will find ituseful for automating many repetitive tasks. There is so much that can be donewith shell scripts that we encourage you to read more about this and to talkwith other Linux users.Linux is replete with so many different commands. Some are powerfullanguages like awk and perl, others are simple handy utilities like head, tail,sort, tr, and diff. There are hundreds of other commands that we don’t evenhave time to mention.1.6RESOURCES• Cameron Newham and Bill Rosenblatt, Learning the Bash Shell, O’ReillyAssociates, ISBN 1565923472.• Ellie Quigley, Linux Shells by Example, 4th ed., Prentice Hall PTR, ISBN013147572X.