Chapter 2. Playing with Files: Viewing, Manipulating, and Editing Text Files
Text files are a mainstay of Unix operating systems. From the password file,
/etc/passwd, to server configuration files, such as
httpd.conf (exact location varies, depending on the system), a computer's behavior is controlled by text files. But what is a text file? E-mail and Usenet messages are text files; HTML web pages are text files; shell scripts are text files; log files are text files. Text files are human-readable and can be edited with any text editor. They can, of course, be viewed, manipulated, and edited with shell scripts.
A Unix operating system does not distinguish between text files and binary files. All files are binary files—text files are just a subset. ...