"text editing" means manipulating the contents of text files. Typically "text file" means the bytes in the file represent 7-bit ASCII characters. unix has been very good at this for a long time.
Ken Thompson, the original author of UNIX, is also the original author of ed, which begat grep, sed, vi and many other text utilities. grep is the standalone implementation of ed's powerful "regular expression" processing features. Regular expressions are sophisticated string matching patterns. If you abbreviate "regular expression" as RE for the purpose of showing command syntaxes that involve regular expressions, the syntax for the ed "global regular expression print" command is g/RE/p . So do look at man ed , since it will tell you alot about sed, ex, grep and unix in general as well.
Text editing is not word processing. "Word processing" generally implies "What You See Is What You Get" (WYSIWYG) interactive creation of documents that will print to hardcopy nicely. cLIeNUX Level 2 won't have a word processor, because they tend to be huge, involving the storage of many detailed fonts. Word Processing also now overlaps other media besides text, such as pictures in a document, further increasing hugeness. Text editing is limited to stuff that will print on a text terminal. ed is a command-oriented line-oriented program, and as such would do powerful manipulations of a text file even if the user's terminal happened to be a paper display teletype, or even a cardpunch machine. The Linux user doesn't have to withstand such hardships, but text editing is still a very powerful thing. 7-bit ascii also supports a few rudimentary non-text facilities, such as beeping the terminal and a few text colors. In Linux you can also assume vt102 virtual terminal escape codes.
If the intended final destination of your text is not a pretty-printed piece of paper, a text editor is still the best tool. I use Pico for most of my editing, and I use vi (or a vi offspring like vim) when I have a lot of command-style editing to do, such as formatting the UNIX Programmers Manual .ps files to ascii or html, or for converting a script from one interpreter to another, such as Bash to dcon, or converting GNU .info files to plain ascii. I have the default editor in Lynx set to Pico, and I am currently switching between Lynx and Pico to edit this file.
Alternatives to word processing should be mentioned. The development of UNIX was originally justified for document processing. Bell Labs used the first UNIX to process patent applications. Creating documents or other output that cannot be viewed interactively by the creator is generally accomplished with some form of "markup" language. For example, HTML stands for "HyperText Markup Language". An html file is plain ascii. The markup language included with the first UNIX was roff, which in turn, I heard somewhere, was a descendant of a utility called runoff. Unix manpages are typically roff markup. The manpages included in cLIeNUX Level 2 are pre-groffed to plain ascii, or are just plain ascii. From the 1971 UNIX Programmer's Manual....
"DESCRIPTION roff formats text according
to control lines embedded in the text."...
That's a pretty basic example of a markup language. roff is line-oriented, due to it's punchcard-era roots. HTML is not, but the basic idea of a markup language is the same. It is markup commands embedded in the text. Dealing with markup at the source level isn't as bad as it may seem. There are problems with WYSIWYG. A lazer printer has much better resolution than a color monitor. UNIX roff was used in the early seventies to produce professionally typeset books, which is ever higher resolution than most late-1990's lazer printers. WYSIWYG has problems with html also. The HTML standard is still in flux, so a WYSIWYG HTML utility has to pick what YOU get from several possible interpretations of the HTML. In these and other cases, what is usually most important is the text content of the document, regardless of the markup. Any text editor can view the text and the markup, and leave the interpretations out.
The only markup interpreter in cLIeNUX Level 2 is Lynx. Level 3 will probably include groff, LaTeX, Netscape, and WYSIWYG conveniences for producing various markup files such as the Lyx WYSIWYG LaTeX editor, and also programmers editors with so-called "Integrated Devlopment Environment" features, and other editing features that are cognizant of the programming language that is being edited. But whether Level 3 ever comes to be or not, my point is this; an understanding of the underlying machine is helpful, if not essential, whatever you are doing. In terms of unix text editing, ed is a good illustration of what the underlying machine is.
It is also possible to edit files that aren't even text. bpe will show any file as a hexadecimal dump and as ascii ( for bytes that are visible as ascii), and allow you to change the bytes in the file as hex numbers or as ascii. bpe can't insert though.
For IBM PC style 8-bit ascii, also called "ANSI graphics" or high-ascii, there is the duhdraw program, similar to the MSDos thedraw program.