.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, if this is the first time you've worked with \'twander\', 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) If this file does not exist or cannot be opened, \'twander\' will display a warning to that effect but continue to run. This is reasonable behavior because \'twander\' provides a command to reload the configuration file without exiting the program (which you would presumably do after fixing the configuration file problem). .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. The Key Bindings are also listed. 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 USE By design, \'twander\' allows you to do almost everything of interest using only the keyboard. Various \'twander\' features are thus associated with particular keystrokes which are described below. It is also very simple to change the default key assignments with entries in the configuration file, also described below. .SH A NOTE ON KEYBOARD 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 it's been mapped in your X server software. Testing \'twander\' on various X servers showed quite a bit of variability in 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\'. The general format is: .TP .B Description (Program Function Name) .PD 000 Default Key Assignment .IP Default Mouse Assignment (if any) .PD .P The "Program Function Name" is the internal variable \'twander\' uses to associate a particular feature with a particular keystroke or mouse action. You can ignore it unless you intend to override the default assignments. This use is described below in the section entitled, .B CHANGING KEYBOARD BINDINGS VIA THE CONFIGURATION FILE. .SS GENERAL PROGRAM COMMANDS This family of commands controls the operation of \'twander\' itself. .TP .B Quit Program (QUITPROG) Control-q Exit the program. .TP .B Re-Read Configuration File (READCONF) 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 (REFRESH) 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 (TOGDETAIL) 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 (CHANGEDIR) 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 (DIRHOME) 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 (DIRBACK and MOUSEBACK) .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 (DIRSTART) Control-s Go back to the original directory in which \'twander\' was started. .TP .B Go Up To Parent Directory (DIRUP and MOUSEUP) .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 (SELALL) Control-Comma Select every item in the current directory. .TP .B Unselect All Items (SELNONE) Control-Period Unselect everything in the current directory. .TP .B Select Next Item (SELNEXT) Control-n Select next item down in the directory. .TP .B Select Previous Item (SELPREV) Control-p Select previous item up in the directory. .TP .B Select Last Item (SELEND) Control-e Select last item in the directory. .TP .B Select First Item (SELTOP) 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. .PP The mouse can also be used to select one or more items. A single-click of the left mouse button selects a particular item. Clicking and dragging selects an adjacent group of items. Clicking an item and then clicking a second item while holding down the "Shift" key also selects an adjacent group of items. Finally, a group non-adjacent items can also be selected. The first item is selected with a single left mouse button click as usual. Each subsequent (non-adjacent) item is then selected by holding down the "Control" key when clicking on the item. .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 (PGDN) Control-v Scroll down one page in the directory listing. .TP .B Scroll Page Up (PGUP) 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 (RUNCMD) 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 (SELKEY and SELMOUSE) .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). If \'twander\' determines that it is running on neither a Unix-like or Win32 system, double-clicking on a file does nothing. .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\' needs a configuration file in order to define commands available to be run. Although the program will run without a configuration file present, it will warn you that it is doing so without any commands defined. Not only are commands defined in this configuration file, but keyboard bindings can optionally be assigned (changed from their defaults) in this file. By default, the program expects to find configuration information in .B $HOME/.twander but you can override this with the .B -c command line option. Actually, \'twander\' can look in a number of places to find its configuration file. It does this using the following scheme (in priority order): .IP If the -c argument was given on the command line, use this argument for a configuration file. .IP If -c was not given on the command line, but the HOME environment variable is set, look for the a configuration file as $HOME/.twander. .IP If the HOME environment variable is not set .B and a -c command line argument was not provided, look for a file called ".twander" in the directory from which \'twander\' was invoked. .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 CHANGING KEYBOARD BINDINGS VIA THE CONFIGURATION FILE No program that runs in many operating environments 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. It is not difficult to override the default keyboard bindings by adding entries in the configuration file. Doing so requires some familiary with how Tkinter names keystrokes. Good resources for learning this exist abundantly on the Internet, among them: .nf http://www.pythonware.com/library/tkinter/introduction/index.htm http://www.nmt.edu/tcc/help/pubs/lang.html http://www.cs.mcgill.ca/~hv/classes/MS/TkinterPres/ .fi Keyboard binding assignments look just like a local variable definition in the configuration file. They take the form: .nf PROGRAM-FUNCTION-NAME = KEYSTROKE .fi Changing the default bindings is therefore nothing more than a matter of assigning the appropriate program function name (found in parenthesis next to the description in the default descriptions above) to the desired keystroke. However, several important rules need to be observed when doing so: .IP It is best if keyboard commands are all Control or Function keys. If you assign anything to a simple key it may conflict with a user-defined command. If you assign anything to a keypad/special key it may conflict with that key's normal GUI behavior. .IP The Tkinter keynames should placed on the right side of the "=" symbol .B without any quotation marks. So, this is correct: .nf QUITPROG = <F3> .fi But, this is not correct: .nf QUITPROG = '<F3>' .fi .IP The key binding variables (the left side of the assignments) are RESERVED and may not be used as names for your own user-defined variables elsewhere in the configuration file. .IP When you're done making changes to the configuration file, be sure to either restart the program or reload the configuration file to assign the new bindings. Be aware that \'twander\' does no sanity testing on the assignments you change. If you assign a particular \'twander\' function to an illegal or silly key string, the program will probably blow-up spectacularly. At the very least, that program feature will probably be unusable, even if \'twander\' manages to run. .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) 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. .B 3) Windows That Don't Disappear On Command Completion It appears that some X Windows implementations (noted on XFree86 / FreeBSD) do not correctly destroy an \'xterm\' window after a command initiated with -e terminates. This is not a \'twander\' problem. The workaround is to manually kill the window or press enter once when the command is complete and the window has focus. .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. The configuration file parser does no validation of key binding override values. It is entirely possible to bind a \'twander\' feature to a bogus key definition. This will cause either a spectacular prgram failure or, at the very least, that feature will not work correctly or at all. The assumption here is that if you are smart enough to want to change key bindings, you're smart enough to learn how Tkinter names keys. You have been warned. 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\' Installation of \'twander\' is fairly simple. .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