Книга: The Linux Command Line
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Shell Functions in Your .bashrc File

Shell functions make excellent replacements for aliases, and they are actually the preferred method of creating small commands for personal use. Aliases are very limited in the kind of commands and shell features they support, whereas shell functions allow anything that can be scripted. For example, if we liked the report_disk_space shell function that we developed for our script, we could create a similar function named ds for our .bashrc file:

ds () {        echo "Disk Space Utilization For $HOSTNAME"        df -h }

In this chapter, we have introduced a common method of program design called top-down design, and we have seen how shell functions are used to build the stepwise refinement that it requires. We have also seen how local variables can be used to make shell functions independent from one another and from the program in which they are placed. This makes it possible for shell functions to be written in a portable manner and to be reusable by allowing them to be placed in multiple programs—a great time saver.

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