The BACKSPACE key rather than the DEL key is set to perform "erase",
ie, to rubout the character before the cursor.

In each user's .login/.bash_login file there exists a tset line which does the reverse of the above. This is there for historical reasons (remember the Vaxen?). This must be undone. Each user should:

1. run the command: fixtset
2. then, completely logout and login again.

This will fix the lowest level mapping. Executing the command:  stty -a
should report: ^H (backspace) set to erase.

Type: echo $SHELL in order to determine which interactive shell you are running. The answer should be either bash or tcsh.

Interactive shells allow command line editing, ie to move left or right along a line by characters or words delete backwards or forwards characters or words. Also to step back or forward through the list of previously executed commands using the up and down cursor keys. Key bindings at the interactive shell level need to reinforce, or at least not override, the basic level mapping of "Backspace" to perform erase. Also, bindings are needed to define control keys for word movement and deletion, with "Del" is set to perform delete forward.
[The function of the cursor keys is usually sorted out internally without the need for explicit bindings ie if you do not tamper with the cursor key bindings at any mapping level they will work just fine!]

Tcsh: Key bindings for tcsh are set in the system DOT/LOGIN file and should not need any user definitions. If any are made they should be in the form of bindkey commands in a user's ~/.login file. As none are required if any are present from times past they should probably be removed!

Bash: Key bindings for bash need to be set in a user's ~/.inputrc file. It is necessary to explicitly enforce that "Backspace" is designated for erase and "Del" for delete forward. The execution of the fixtset command (see above) will also automatically execute fixinputrc to ensure these mappings are correctly installed.

Any mappings that use the xmodmap command (usually in the file .xinitrc) should be removed, or at least commented out. xmodmap is a crude way to achieve what should have been set at the lowest level (section 1).

X-terminals, ie command windows in which interactive shells are run, so all the mappings described above are effective. A few extra bindings pertinent to an xterm environment can be made. For example, xterms have a vertical scroll bar so that you can look back up at previous output. For example, a Sun keyboard has two keys labelled "PgUp". These can be bound to ``page up'' the screen. By contrast, in a document viewing program, eg ghostview, they can be bound to view the previous page of a document.

The reference file for X application specific key bindings is:

        /usr/local/DOT/.Xdefaults

Users should have a paragraph headed xterm.vt100.translations which, at the time of writing contains lines referring to PRIMARY,CLIPBOARD which pertain to cutting and pasting, lines to referring to the keys "Home", "End", "Prior" and "Next" which pertain to line editing (beginning or end) and scrolling. To automatically replace the mappings in your ~/.Xdefaults file by the standard set, use the local command: fixmapxterm

If one holds down the LH mouse button and draws the mouse over some text, this will be highlighted. In generic X applications when the mouse button released the highlighted text is drawn into the PRIMARY buffer. If one moves to another generic X application, the contents of the PRIMARY buffer is regurgitated when the centre button is pressed as if the text had been typed in on the keyboard. Thus, if one is in a text editor ensure the editor is in text insert mode before pressing the regurgitation button in order for the text to be inserted correctly.

Sun Generic Applications do not use the PRIMARY buffer but an alternative buffer called the CLIPBOARD. Sun applications have a distinctive appearance, and you just have to learn which applications belong to this stable. To mark text to be copied, hold down the LH mouse button and draw the mouse over the text (as above). The text is not actually stored in the buffer until the Copy key is pressed. When the Copy key is pressed (alternatively, on non-Sun keyboards, META+C) the highlighted text is copied into the CLIPBOARD buffer.

The regurgitation of the CLIPBOARD buffer is achieved by pressing the Paste, or META+P, key(s).

The xterm key bindings described in the previous section facilitate cutting and pasting between Sun and xterm applications by allowing, in xterms, the Copy key to copy into both buffers and conversely the Paste key to regurgitate from either buffer.

A little experimentation will enable the nuances to be learned.

All the above should work if you can identify the correct META key to use in conjunction with C and P keys.

Copying what is on the screen is exactly that, you are copying the visible portrayal of what was used to produce the text and NOT the original character stream that produced that image.

For example, if tabulated data separated using ``tabs'' is copied, what is actually copied will be the spaces the ``tabs'' expanded to at the time. Hence, programmers should never cut and paste between ``make'' files, the syntax of which demands tabs precede each method line.

Some characters are displayed as two printing characters, eg CONTROL-G is a single character but displayed as two ^G, (or not displayed at all as ^G is the code to ring the bell). When such text is copied, it is the two printed characters that are copied, not the original control-G.

The file /usr/local/DOT/.exrc is the skeleton on which all users should base their own copy, ~/.exrc. The skeleton contains the necessary mappings to enable the cursor keys to behave sensibly when in insert (text entry) mode. They actually terminate text entry (ESC) and then do the specified move.
Caution: The skeleton file contains raw control characters that cannot be cut and pasted into a user's copy. Instead, the content of the skeleton file must be read into the user's file, either by using cat, ie:

        cat /usr/local/DOT/.exrc >>~/.exrc

        vi ~/.exrc
        :r /usr/local/DOT/.exrc