ops102_3_2.pdf

Text Files and Text Editors OPS102 Week 3 Class 2 Tiayyba Riaz/John Sellens May 21, 2024 Seneca Polytechnic Outline What is a Text File? Text Editors OPS102 W3C2 - Text Files and Text Editors 1/9 What is a Text File? Files, Files, Files Last class we mentioned:...

Text Files and Text Editors OPS102 Week 3 Class 2 Tiayyba Riaz/John Sellens May 21, 2024 Seneca Polytechnic Outline What is a Text File? Text Editors OPS102 W3C2 - Text Files and Text Editors 1/9 What is a Text File? Files, Files, Files Last class we mentioned: Data is saved in files In Linux/Unix we really like text files For data, presentations, configuration, logs, and more The system and shell provide “easy” ways to deal with files More about file details next week OPS102 W3C2 - Text Files and Text Editors 2/9 Line Endings in Text Files Each line in a text file as some end-of-line indicator. In UNIX/Linux it’s “new line” (line feed or ^J or \n). In Windows, it’s “carriage return” (^M or \r) followed “line feed”. In MacOS, it’s “carriage return” (^M or \r). When text files are transferred between systems, there could be problems. A file moved from Windows to Linux might show some empty lines or ^M’s A file moved from Linux to Windows may miss the line breaks. Some text editors notice and try to help you out. See the dos2unix(1) and unix2dos(1) commands. Remember how manual typewriters and teletype machines worked? OPS102 W3C2 - Text Files and Text Editors 3/9 Text Editors Text Editors A text editor allows users to create, modify and save editing changes of text files. Editing text files is an everyday activity for both programmers as well as administrators on a Unix and Linux system. Edit System configuration files Write Scripts and programs Write/edit documentation Develop web pages It is important to learn to be able to user a text editor in order to install, configure and run network services. OPS102 W3C2 - Text Files and Text Editors 4/9 Text Editors – History Before there were video (CRT) terminals, when paper terminals were the rule, “line editors” were used e.g. qed, ed, edlin (DOS) On Unix, the ed(1) editor was replaced by ex(1) (short for EXtended) https://en.wikipedia.org/wiki/Ex_(text_editor) And then a ”visual mode” for ex was created, and the vi(1) editor was born. https://en.wikipedia.org/wiki/Vi ex and vi both came from Bill Joy at UCBerkeley and appeared first in BSD. Syntax that originated in ed(1) is still part of vi(1), sed(1), and other tools. The grep(1) command echoes the ed syntax of: g/regexp/p OPS102 W3C2 - Text Files and Text Editors 5/9 Text Editors – Many Choices Today There are a number of editors available in Linux and Windows. Try several, choose the one that’s best for you. Examples of some common and well known text editors: VIM Nano Gedit Notepad Notepad++ Sublime See also: https://en.wikipedia.org/wiki/Comparison_of_text_editors You will learn some basics of the nano editor in next slides. Nano is the default text editor for many Linux distributions. OPS102 W3C2 - Text Files and Text Editors 6/9 Nano Text Editor Introduction The Nano text editor is an easy to use text editor. Installed on many/most, but not all, Linux systems. Run the command nano and the editor will open for you. Nano editing commands typically control characters. For example, the notation ^G means press and hold the ”control” key on the keyboard, then press the G key. For nano you don’t need to memorize many commands, since the menu is always at the bottom of the nano screen. OPS102 W3C2 - Text Files and Text Editors 7/9 More About Nano Some basic commands include: ^G – to get help at any time ^R – open a file ^O – save a file ^W – find ^\ – replace ^X – exit Nano Editor Start Up Screen OPS102 W3C2 - Text Files and Text Editors 8/9 Nano vs Vi These days, the vi(1) command is often actually vim(1). vim(1) adds many more modern features to classic vi. Many intended specifically for programmers. For casual, occasional use, the nano editor is fine. For anything beyond the absolute basics, you really should become familiar with vi (or vim) Check out the vimtutor(1) command to get started. OPS102 W3C2 - Text Files and Text Editors 9/9