ntrOduCtiOn<br >LE HANDLING<br > This book presents the basic concepts of file processing using the<br >COBOL computer programming language. This chapter provides a short<br >introduction to files and a framework for the logic which is used in the<br >programs of this book.<br > We are all familiar with files that are not computer related. For exam-<br > ~}le， many files are maintained in file folders in file cabinets. Data in these<br >~iles may be typed or written， if we want to change these data， we open the<br >file cabinet and make the necessary changes. We can add new records by<br >~)reparing a new file foMer and including it in the appropriate position in<br >;he file.Records can be remove(1 an(I discarded when they are no longer<br >:leede(l.<br > l~et s look at a specific example. Suppose that the manager of a dormi-<br >Lory facility has a file on paper in which information about residents is main-<br >:ained.There is one file folder for each resident. Each folder contains a<br >~ esident s name， room number， sex， and other" information. The records<br >are placed in alphabetical order" by the resident s name. As people move<br >n and out of the dormitory， records are added or deleted. As people<br >:hange rooms the file is opened， and room numbers are changed.<br > In this example the total collection of information is a file. A file is a<br >: ollection of records which are related in some way and which are main-<br >.ained in some order. Here we have established information about indi-<br >dduals living in a dormitory in order by name.<br > The information about one individual is a record. In out" record we have<br >