Computer programs are all about working with data. In past chapters, we have focused on processing data at the file level. However, many programming problems need to be solved using smaller units of data such as strings and numbers.
In this chapter, we will look at several shell features that are used to manipulate strings and numbers. The shell provides a variety of parameter expansions that perform string operations. In addition to arithmetic expansion (which we touched upon in Chapter 7), there is a common command-line program called
bc, which performs higher-level math.
Though parameter expansion came up in Chapter 7, we did not cover it in detail because most parameter expansions are used in ...