Introduction to File Processing

A file is a series of bits of data that are arranged in a particular way to produce a usable document. For easy storage, location, and management, the bits are stored on a medium such as a hard disc, a floppy disc, a compact disc, or any valid and supported type of storage. When these bits belong to a single but common entity, the group is referred to as a file. For even greater management, files can be stored in a parent object called a directory or a folder. Since a file is a unit of storage and it stores information, it has a size which is the number of bits it uses. To manage it, a file has a location also called a path that specifies where and/or how the file can be retrieved. Also, for better management, a file has attributes that indicate what can be done on the file or that provide specific information that the programmer or the operating system can use when dealing with the file.

File processing consists of creating, storing, and/or retrieving the contents of a file from a recognizable medium. For example, it is used to save word-processed files to a hard drive, to store a presentation on a floppy disk, or to open a file from a CD-ROM. To perform file processing on a Visual C++ .NET application, the .NET Framework provides various classes.

In order to manage files stored in a computer, each file must be able to provide basic pieces of information about itself. This basic information is specified when the file is created but can change during the life time of a file. To create a file, a user must first decide where it would be located: this is a requirement. A file can be located on the root drive or it can be positioned inside of an existing folder. Based on security settings, a user may not be able to create a file just anywhere in the (file system of the) computer. Once the user has decided where the file would reside, there are various means of creating files that the users are trained to use.

When creating a file, the user must give it a name following the rules of the operating system combined with those of the file system.

At the time of this writing, the rules for file names for Microsoft Windows were on the MSDN web site at Windows Development\Windows Base Services\Files and I/O\SDK Documentation\Storage\Storage Overview\File Management\Creating, Deleting, and Maintaining Files\Naming a File (because it is a web site and not a book, its pages can change anytime).

The most fundamental piece of information a file must have is a name. Once the user has created a file, whether the file is empty or not, the operating system assigns basic pieces of information to it. Once a file is created, it can be opened, updated, modified, renamed, etc.