If you created your files on a DOS computer, your files probably end with an .htm extension. These files should be renamed so that they have an .html extension although .htm should work. Renaming files in UNIX is simple. Let's assume that you want to change a file called example.htm to index.html . You can use up to 256 characters in any file or directory name.
Extensions are optional and unlimited.
Do not put spaces in your filenames. UNIX filenames are case sensitive. In order for your files to be accessed, you must give users permission to use them. You'll see a list of files that looks a little different than the list you saw when you used the plain ls command. The information on the far left indicates what type of permission is given to each file and directory.