Configuring the environment

The shells and the individual applications often allow a high degree of configuration. This can result in the screens for one person looking and behaving differently to those of another. This configuration can be done on a system-wide basis, overridden on an individual basis.

There are lots of bits, and much detail in here...

Zsh

Login

When you first login, bash reads a startup file .profile (in your home directory). This contains initialisation instructions for your shell environment. This is a good place to set your PATH variable if needed. To run testit, put this in your .profile: 
PATH=/student1/os/ostutes/bin:$PATH
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Shell startup

Every time you invoke a non-login shell, the file .bashrc (in your home directory) is read. This is a good place to put aliases, etc. [an error occurred while processing this directive] Add comment

Prompt

The normal prompt is stored in the shell variable PS1. Set this to change the prompt. Various substitutions are performed on the value of PS1 before it is printed. PS1="[\h \w \! \t]" prints as 
[umi ~/access 517 09:29:49]
on my machine.

The bash man page has more information on these. [an error occurred while processing this directive] Add comment

Functions

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Other shells

Just for completeness. Other shells use .profile, .login, .logout, .cshrc, etc.

Search path

Commands are searched for on the search path, which is a `:' separated list of directories. The search is strictly left-to-right. This is set in the PATH variable, which will be set to something like PATH=.:/bin:/usr/bin This is usually set in the .profile. You can change it to include additional directories. Don't remove directories, or some commands will stop working. [an error occurred while processing this directive] Add comment

Shell

The command chsh can be used to set your login shell to one of the other available ones.

Net news

The list of newsgroups currently known is stored in the file .newsrc in your home directory. This consists of a list of lines such as aus.general! 1-8191 aus.auug: 1-1180 The `:' shows that aus.auug is currently subscribed to, the `!' that aus.general is not. The list at the end shows how much of the news has been read in each group.

You can edit this file and choose which groups you want to read by setting the `:' or `!' for each group. Allow about an hour.

If you use the newsreader nn the order in which groups are presented for reading may be controlled by the file .nn/init in your home directory. The groups in the list there are those presented first.

X Window startup

The X Window system is started from a login shell run by xdm. This executes a startup script /pub/local/lib/X11/xdm/Xsession. This runs a set of commands. These are all run asynchronously except for xlogout - when xlogout terminates the X Window session terminates.

You can change the startup behaviour for X by creating a file .xsession in your home directory. Be very careful doing this - if you mess it up you can't login. [an error occurred while processing this directive] Add comment

X resources

The appearance and some behaviour of X programs is controlled by resources. A resource is a property such as height, width, foreground colour, font, etc.

The application as a whole has resources, and individual components such as labels and buttons also have resources.

Application resources may be set by command line keyword options (not positional). Some example options are

-foreground white \ -background black \ -geometry 80x24+0+0 which could be used for a white on black 80 column by 24 row xterm at the origin (0,0). 
xterm -foreground red -background green
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Resource database

This mechanism is used on a one-off basis. To make all xterms use a particular font, a resource database is used. The easiest way to put values into this database is to put them in the resource file .Xdefaults. This file is typically read whenever an application starts. The simplest format is app-name*resource: value as in xterm*foreground: white xterm*background: black An alternative is to use the ``class name'' as in XTerm*foreground: white [an error occurred while processing this directive] Add comment

Fonts

Fonts are complicated. A font is usually designed by a company. There is a point size, a weight (bold, light), slant (italics, roman) and lots of other goodies. Use the program xfontsel or xfbrowse to browse the 900-odd fonts available. Once you have one you like, set it in the resource file for use by all applications.

The font used is controlled by the resource ``font'' for Athena-based applications, and ``fontList'' for Motif applications:

*font: -misc-fixed-bold-r-normal--15-140-75-75-c-90-iso8859-1 *fontList: -misc-fixed-medium-r-normal--15-140-75-75-c-90-iso8859-1 [an error occurred while processing this directive] Add comment

Xterm

An xterm can be set to run a Unix command using the -e option. Everything from the -e on is taken to be a command. For example, running pine within an xterm is done by xterm -e pine You can show in the title bar that it is nn by also setting the -title option: xterm -title pine -exec pine An xterm also has additional resources. To have a scrollbar showing, the resource XTerm*scrollBar: True should be set. This allows you to use the mouse to scroll up and down.

Text can be copied from an xterm to the clipboard by dragging over it with the left button (it highlights the selected text). It can then be pasted into an xterm by pressing the left button. It will be inserted at the cursor insertion point. Other X applications may also allow copying to and from the clipboard.

To bind the PageUp and PageDown keys to the scrollbar, the translations resource should be set as well:

xterm*vt100.translations: #override\n\ <KeyPress>Home:\ scroll-back(100,page) \n\ <KeyPress>End:\ scroll-forw(100,page) \n\ <KeyPress>Prior: \ scroll-back(1,page) \n\ <KeyPress>Next: \ scroll-forw(1,page) [an error occurred while processing this directive] Add comment

Moxfm

moxfm is the file manager used now. It shows a central file screen, plus applications around the side. The configuration files are kept in $HOME/.fm. You can edit an icon by clicking the right button on it. You can add icons by clicking the right button on the background. You can place an icon onto the desktop by dragging it. [an error occurred while processing this directive] Add comment
This page is http://pandonia.canberra.edu.au/OS/l3_2.html, copyright Jan Newmarch.
It is maintained by Jan Newmarch.
email: jan@ise.canberra.edu.au
Web: http://pandonia.canberra.edu.au/
Last modified: 6 August, 1996