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