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34 – Strings And Numbers
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 well-known command line program called bc, which performs higher level math.
Parameter ExpansionBasic ParametersExpansions To Manage Empty VariablesExpansions That Return Variable NamesString OperationsCase ConversionArithmetic Evaluation And ExpansionNumber BasesUnary OperatorsSimple ArithmeticAssignmentBit OperationsLogicbc – An Arbitrary Precision Calculator LanguageUsing bcAn Example ScriptSumming UpExtra CreditFurther Reading