Your Unix files are stored on a magnetic disk, from which you may easily retrieve them to work with. All of your files are referenced by names which you choose and assign to them. Creating Files Files are created through use of a text editor, which is a special utility program designed to assist you in entering text and in making changes and updates to text you have already entered. Naming Files Unix allows file names of up to 256 characters in length, including any printable characters except the forward slash. It is best, however, to avoid characters such as the semicolon, the ampersand, the asterisk, and so on, because these can conflict with certain Unix commands.
Most users choose from the alphanumeric characters, the period and the underscore.
A period in a file name has no special significance, as Unix does not require file types or extensions, although language compilers will use them. Some Unix file names begin with a period. Hidden files are used to define various startup parameters, and allow you considerable leeway in customizing your environment . Be consistent in your usage. Some Commands for Manipulating Files ls Lists the names of files in your current directory.