.TH twander 1 "TundraWare Inc."

.SH twander

Wander around a filesystem executing commands of your choice on
selected files and directories. If you're new to \'twander\' and want
to know why this program is better and different than whatever you're
using at the moment, take a moment to read the section called 
.B "DESIGN PHILOSOPHY" 
toward the end of this document first.  Similarly, there is a
section towards the end of this document entitled
.B "INSTALLING \'twander\'"
which describes how the program should be installed.

.SH SYNOPSIS
twander [-bcdfhnqrstvwxy] [startdir]

.SH OPTIONS
.TP
.B startdir
Directory in which to begin. (default: ./)

If this directory does not exist or cannot be opened, \'twander\'
will display an error message and abort.

.TP
.B -b backcolor
Desired background color. (default: black)

.TP
.B -c path/name of configuration file
Specify the location and name of the configuration
file. (default is ~/.twander)

.TP
.B -d
Start in debug mode.  (default: debug off)

The program runs, but does not actually execute any commands.
Instead, the contents of various internal tables such as the Symbol
Table and Command Table are listed on standard output.  If the user
presses a defined command key, the command that would have been
executed is printed to standard output, but no command is actually
performed.  This option is mildly useful in debugging configuration
files insfar as it will display the command string after all
substitutions of variables (both built-ins and user-defined) has been
done.

.TP
.B -f forecolor
Desired foreground color. (default: green)

.TP
.B -h
Print help information on stdout.

.TP
.B -n fontname
Name of desired font family. (e.g., courier, times, helvetica) (default: courier)

.TP
.B -q
Quiet mode - suppresses warnings. (default: warnings on)

.TP
.B -r 
Turn off automatic refreshing of directory display. (default: refresh
on)

Normally, \'twander\' re-reads and displays the current directory
every few seconds to reflect any changes that might have occured to
that directory's contents.  This option is useful on slow machines (or
slow X connections) and/or when working with very large directories.
In this situtation, the frequent updating of the \'twander\' display
can make the program unacceptably slow and unresponsive.  In this case
you can still force an update manually with the Control-l key.

.TP
.B -s fontsize
Font size in points. (default: 12)

.TP
.B -t
Turn off quoting when substituting built-in variables. (default: quoting on)

Anytime \'twander\' encounters a reference to one of the built-in
variables (DIR, DSELECTION, DSELECTIONS, PROMPT:, SELECTION,
SELECTIONS) in a command, it will replace them with
.B double quoted
strings.  This is necessary because any of these can return values which
have embedded spaces in them.  By quoting them, they can be passed to a
command or script as a single item.  The -t option disables this behavior
and replaces the built-in variable with unquoted literals.

.TP
.B -v
Print detailed version information.

.TP
.B -w fontweight
One of:  bold, italic, underline, overstrike. (default: bold)

.TP
.B -x width
Set window width. (default: 60)

.TP
.B -y width
Set window width. (default: 25)

.SH KEYBOARD BINDINGS AND HOW TO CHANGE THEM

No program that runs on many operating systems can satisfy 
everyone's (anyone's!) idea of what the "correct" key bindings
should be.  An emacs user, vi user, BSD user, and Windows user
are going to differ considerably on what keys should be bound
to what feature.

So, what follows is documentation on
the
.B default
key bindings.  However, it is not difficult to change the
defaults.  They are listed near the top of the program
file (twander.py) to allow people to tailor them as they
wish.  The only thing you need to know is the Tkinter
nomenclature for keystroke names.  You can get a pretty
good idea of this from reading the first part of the
program, and failing that, there is abundant documentation
of this topic on The Net.

The only convention that ought to be observed here (to keep
the program sane - it assumes this convention throughout), is
that
.B keyboard navigation and selection commands are Control keys.

The obvious question here is, "Why isn't this a configuration option
maintained in the configuration file?"  The answer is that it would
make the configuration file parser overly complex to handle something
which should be changed very rarely, if at all.  The downside to this
approach is that per-user customization requires each user to keep a
copy of \'twander.py\' in their own directory space.


.SH ARROW AND KEYPAD BEHAVIOR

Generally, the arrow and keypad keys should do what you would expect
on the system in question. On Win32 systems, particularly, there ought
to be no odd arrow/keypad behavior.  

X-Windows is somewhat more problematic in this area.  Just what an
arrow key is "supposed" to do depends on how its been mapped in your X
server software.  Testing \'twander\' on various X servers showed
quite a bit of variability on how they handled the arrows and keypad.
So ... if you're running in an X Windows universe and arrows or keypad
do nothing, or do strange things, look into your key maps, don't blame
\'twander\'.

.SH DEFAULT KEYBOARD AND MOUSE BINDINGS


Here, ordered by category, are the default keyboard and mouse
bindings for \'twander\':

.SS GENERAL PROGRAM COMMANDS

This family of commands controls the operation of \'twander\' itself:

.TP
.B Quit Program
Control-q

Exit the program.

.TP
.B Re-Read Configuration File
Control-r

Re-read the configuration file.  This allows you to edit the
configuration file while \'twander\' is running and then read your
changes in without having to exit the program.  This is handy when
editing or changing command definitions.  However, if you edit the
configuration file and introduce an error, \'twander\' will terminate
when you try to re-read it (just as it will if you try to start the
program with a bad configuration file).

.TP
.B Refresh Display
Control-l

Re-read the current directory's contents and display it.  This is most useful
if you have turned off automatic directory refreshing with the -r command
line flag.  

.TP
.B Toggle Details
Control-t

Toggle between detailed and filename-only views of the directory.


.SS DIRECTORY NAVIGATION

This family of commands controls movement between directories.  If at any point,
you attempt to navigate into a directory that does not exist or which
does not have appropriate permissions, \'twander\' will issue an appropriate
message, and remain in the original directory where the request was issued.
This is
.B unlike
the case of a non-existent or unreadable directory specified when the program
is first started.  In that case, \'twander\' reports the error and aborts.

.TP
.B Change Directory
Control-x

This is a shortcut that allows you to directly move to a new directory/path -
i.e., Without having to navigate to it.


.TP
.B Go To Home Directory
Control-h

If the "HOME" environment variable is defined on your system, this will move
you to that directory.  If the "HOME" environment variable is not defined,
this command will move to the original starting directory.

.TP
.B Go Back One Directory
.PD 000
Control-b
.IP
Control-DoubleClick-Left-Mouse-Button
.PD

\'twander\' keeps track of every directory visited and the order in
which they are visited.  This command allows you to move back
successively until you get to the directory in which you started.
This feature is implemented as a stack - each "backing up" removes
the directory name from the visited list.  The "Directory" menu (see
.B MENU OPTIONS
below) implements a similar feature in a different way and keeps track of
all directories visited regardless of order, never discarding any entry.

.TP
.B Go To Starting Directory
Control-s

Go back to the original directory in which \'twander\' was started.

.TP
.B Go Up To Parent Directory
.PD 000
Control-u
.IP
Control-DoubleClick-Right-Mouse-Button
.PD

Move to the parent of the current directory ("..").


.SS SELECTION KEYS

This family of commands controls the selection of one or more (or no)
items in the current directory:

.TP
.B Select All Items
Control-Comma

Select every item in the current directory.

.TP
.B Unselect All Items (Select Nothing)
Control-Period

Unselect everything in the current directory.

.TP
.B Select Next Item
Control-n

Select next item down in the directory.

.TP
.B Select Previous Item
Control-p

Select previous item up in the directory.

.TP
.B Select Last Item
Control-e

Select last item in the directory.

.TP
.B Select First Item
Control-a

Select first item in the directory.  This will always be the
".." entry, but it is a quick way to get to the first part of
a very long directory listing which does not all fit on-screen.

.SS SCROLLING COMMANDS

If a given directory's contents cannot be displayed on a single
screen, \'twander\' supports both vertical and horizontal scrolling
via scrollbars.  This capability is doubled on the keyboard with:

.TP
.B Scroll Page Down
Control-v

Scroll down one page in the directory listing.

.TP
.B Scroll Page Up
Control-c

Scroll up one page in the directory listing.


.SS COMMAND EXECUTION OPTIONS

This family of commands causes \'twander\' to actually
attempt to execute some command you've chosen:

.TP
.B Run Arbitrary Command
Control-z

This is a shortcut that allows you to run any command you'd like
without having to define it ahead of time in the configuration file.
It is more-or-less like having a miniature command line environment at
your disposal.

.TP
.B Run Selected File / Move To Selected Directory
.PD 000
Control-space
.IP
DoubleClick-Left-Mouse-Button
.PD

If the selected item is a Directory, \'twander\' will move into
that directory when this command is issued.  If the selected item
is a file, \'twander\' will attempt to execute it.  Whether or not
the file is actually executed depends on how the underlying operating
system views that file.  

In the case of Unix-like operating systems, the execute permission
must be set for the user running \'twander\' (or their group) for the
file to be executed.

On Win32, the file will be executed if the user has permission to do
so
.B and
that file is either executable or there is a Windows association
defined for that file type.  For example, double-clicking on a
file ending with ".txt" will cause the file to be opened with
the \'notepad\' program (unless the association for ".txt" has
been changed).

.TP
.B Run User-Defined Command
User-Defined (Single Letter) Key

Each command defined in the configuration file has both a "Command
Key" and a "Command Name" associated with it.  Pressing that key
will cause the command associated with it to be run.  If no command
is associated with a given key, nothing will happen.


.SH MENU OPTIONS

Although \'twander\' is primarily keyboard-oriented, several
menu-based features are also implemented to make the program
more convenient to use.  These menus appear at the top of the 
\'twander\' display window, above the directory listing. 

The first item in each menu is a dashed line ("----") which indicates
that it is a "tearoff" menu.  Clicking on the dashed line will detach
the menu from \'twander\' allowing it to be placed anywhere on screen.
Even when detatched, these menus remain current and in-sync with
\'twander\' as it continues to run.  You can also tear off multiple
instances of these menus if you'd like copies of them at several
locations on the screen simultaneously.

.SS Commands MENU

Every command defined in the configuration file is listed in this menu
by its "Command Name".  Clicking on an item in this menu is the same
as invoking it from the keyboard by its "Command Key".  This is 
a convenient way to invoke an infrequently used command whose
command key you'e forgotten.  It is also handy to confirm which commands
are defined after you've edited and reloaded the configuration file.

.SS Directories MENU

\'twander\' keeps track of every directory visited.  The previously
described command to move "Back" one directory allows directory naviation
in reverse traversal order - you can back up to where you started.
However, this feature "throws away" directories as it backs up, sort
of like an "undo" function.  

The "Directories" menu provides a slightly different approach to the
same task.  It keeps permanent track of every directory visited and
displays that list in sorted order.  This provides another way to move
directly to a previously visited directory without having to explictly
navigate to it again, back up to it, or name it explictly using the
"Change Directory" command.


.SH LOCATION OF CONFIGURATION FILE

\'twander\'
.B requires
a startup configuration file in order to run.  It is in this file that
the user defines the commands which can be applied to the files and
directories selected in the program GUI.

By default, the program expects to find configuration information in
.B ~/.twander
but you can override this with the
.B -c 
command line option.


.SH CONFIGURATION FILE FORMAT


\'twander\' configuration files consist of freeform lines of
text.  Each line is considered separately - no configuration
line may cross into the next line.  Whitespace is ignored within
a line as are blank lines.

There are only three possible legal lines in a \'twander\'
configuration file: Comments, Variable Definitions, and 
Command Definitions.  Everything else is considered invalid.
\'twander\' will respond with errors or warnings as is 
appropriate anytime it encounters a problem in a configuration
file.  This is both true when the program initially loads as
well as during any subsequent configuration file reloads
initiated from the keyboard while running \'twander\'.


.SH GOTCHAS

There are several tricky corners of \'twander\' which need
further explanation:

.B 1) Getting Command Results Displayed In A New Window

When you invoke a command via \'twander\', whether via a command
definition in the configuration file or the keyboard shortcut, you
generally want it to run in a new window.  If the program you are
running is GUI-aware, this should not be a problem.  However, if you
are using \'twander\' to run a command line program or script, you
have to take extra care in the formulation of the command string.
In the case of Unix-like systems you have to invoke the command
so that it runs in some GUI context.  Say you want to use a pager like
\'less\' to view files.  You would expect that this entry might do it:

.nf
V   view    less [DSELECTIONS]
.fi

Sadly, this will not work, at least not the way you expect.
If you started \'twander\' from a terminal session and use
the command above, it will work, but the results will appear
in the invoking terminal window,
.B not
in a new window as you might expect. If you started \'twander\'
from a GUI or disconnected it from the initating terminal with
a \'nohup\' ... & invocation, you will get
.B no
output.  This is not a \'twander\' problem, it is innate to
how command line programs run under Unix shell control.  To achieve
the desired results, you'll need something like this in your
configuration file:

.nf
V   view         xterm -l -e less [DSELECTIONS]
.fi

This causes your command line program to execute in an \'xterm\'
context.

This is not so much of an issue on Win32 systems where the first
form of the command above works fine.

.B 2) Non-Modal Operation Of New Windows

Notice our example commands above do not end with "&". 
These should not be needed on either Unix-like or Win32
operating systems.  When a command is executed, \'twander\'
starts a new thread of execution which runs concurrently
with \'twander\' itself.  This means you should be able to
continue using \'twander\' while the new command executes.
If not (\'twander\' is locked out while the new command runs -
so-called "modal" operation), it means your system does not
completely or correctly implement threading.  In that case,
if you want non-modal command operation, try adding a "&" at
the end of your command definition.


.SH OTHER
You must have Python 2.2 or later installed as well as Tkinter
support installed for that release.  In the case of Win32, Tkinter
is bundled with the standard Windows Python distribution.  In
the case of Unix, you may have to first install Python and
then the appropriate release of Tkinter.  This is the case,
for example, with FreeBSD.

.SH BUGS AND MISFEATURES
The color options (-b, -f), font options (-n, -s, -w), and size option
(-x, -y) are
.B not
checked for validity when the command line is initially read.
If you enter something unreasonable for
these options, \'twander\' will refuse to run with some
.B really
interesting and entertaining error messages.  The program could be
more gracious about this.

This program has not been tested on MacOS.  Please let me know how/if
it works there and any issues you discover.

.SH INSTALLING \'twander\'

.SH DESIGN PHILOSOPHY
Graphical User Interfaces (GUIs) are a blessing and a curse. On the
one hand, they make it easy to learn and use a computer system.  On
the other, they are a real inconvenience to experienced users who are 
touch typists.  Taking hands off the keyboard to use the mouse
can really slow down a good typist.

Nowhere is this more apparent than in filesystem browsers.  In one
corner we have the GUI variants like \'Konqueror\' and \'Microsoft
Windows Explorer\'.  These are very easy to use but you pretty much
need the mouse in your hand to do anything useful.  In the other
corner are the text-based file browsers like \'List\', \'Norton
Commander\', and \'Midnight Commander\'.  These are really efficient
to use, but have limited functionality and generally do not operate
very well on
.B groups
of things.

Both of these approaches also suffer from the well-known
interface problem of "What You See Is
.B All
You Get" - Each program has a predefined set of commands and the user
cannot easily extend these with their own, new commands.

\'twander\' is a new approach to the filesystem navigation problem which
embraces the best of both the GUI-based approach and the text-based
approach.  It also provides a rich mechanism whereby each user can
easily define their own command set and thereby customize the program
as they see fit.  This is done with a number of key features:


.TP
1)
The
.B Navigation
of the filesystem is graphical - you can use the mouse to select files,
directories, or to change directories.  However, each major filesystem
navigational feature is also doubled on the keyboard (using Control keys)
so you can move around and select things without ever touching the mouse.

.TP
2)
\'twander\' also supports a number of
.B navigation shortcuts.
It provides single control-key access to changing directories, moving
to the previous directory, moving up one directory level, moving to
any previously visited directory, (de)selecting any or all
files/directories in the current view, and escaping to the operating
system to run a command.  Some (but not all) of these features are
also doubled via GUI/mouse operations.

.TP
3)
There are
.B no
built-in file or directory commands.  All commands which manipulate
the files or directories selected during navigation are user-defined.
This command definition is done in an external configuration file
using a simple but powerful command macro language.  This means that
that the command set of the program can easily be changed or expanded
without having to release a new version of \'twander\' every time.
Better still, every different user can have their own command set
defined in a way that suits their style of working.  Best of all,
commands can be invoked either graphically (with a mouse click) or via
a single keypress to minimize moving your hands off the keyboard.

.TP
4)
Because \'twander\' is written in Python using Tkinter, the same
program runs essentially identically on many Unix-style and Win32
systems.  The only thing that may need to be changed across these
various platforms are the command definitions in the configuration
file.  You only need to learn one interface (and the commands you've
defined) across all the different systems you use.

.P
The consequence of all this is that \'twander\' is an extremely
powerful and highly customizable filesystem navigator.  Once
learned, both navigation and command execution are lightning-fast
(or at least, as fast as your machine can go ;) while minimizing
dependency on the mouse.

.SH COPYRIGHT AND LICENSING
\'twander\' is Copyright(c) 2002 TundraWare Inc.  For terms of use, see
the twander-license.txt file in the program distribution.  If you
install \'twander\' on a FreeBSD system using the 'ports' mechanism, you
will also find this file in /usr/local/share/doc/twander.

.SH AUTHOR
.nf
Tim Daneliuk
twander@tundraware.com