The WRspice help system provides a cross-referenced rich-text (HTML) database on the commands and features of the program. The system is entered at the top level by pressing the Help button in the Help menu of the Tool Control window, or by giving the help command without arguments. If a command name or other known keyword is given as an argument to the help command, the help system will start by displaying the help for that topic.
When graphics is not available, the help text will be presented in a text-only format in the console window. The HTML to ASCII text converter only handles the most common HTML tags, so some descriptions may look a little strange. The figures (and all images) are not shown, and clickable links will not be available, other than the ``references'' and ``seealso'' topics.
Clicking on a colored HTML reference will bring up the text of the selected topic. If button 1 is used to click, the text will appear in the same window. If button 2 is used to click, a new help window containing the selected topic will appear.
Text shown in the viewer that is not part of an image can be selected by dragging with button 1, and can be pasted into other windows in the usual way.
The viewer can be used to display any text file or URL. In Xic and its derivatives, pressing the question mark key (``?'') will prompt the user for text to display. The !help command has the same effect. In WRspice, the text to display can follow the ``help'' command keyword on the command line. The name given to the command, or to to the Open command in the viewer's File menu, can be
If the given name can be resolved, the resulting page will be displayed in the viewer. Also, the HTML viewer is sensitive as a drop receiver. If a file name or URL is dragged into the viewer and dropped, that file or URL is read into the viewer, after confirmation.
The ability to access general URLs should be convenient for accessing information from the Internet while using Xic and WRspice. The prefix ``http://'' must be provided with the URL. Thus, for example,
help http://wrcad.comwill bring up the Whiteley Research web page. The links can be followed by clicking in the usual way. Of course, the computer must have Internet access for web pages to be accessible.
Be advised, however, that the ``mozy'' HTML viewer used in Unix/Linux releases is HTML-3.2 compliant with only a few HTML-4.0 features implemented, and has no JavaScript, Java or Flash capabilities. A few years ago, this was sufficient for viewing most web sites, but this is no longer true. Most sites now rely on css styles, JavaScript, and other features not available in mozy. Most sites are still readable, to varying degrees, but without correct formatting.
The given URL is not relative to the current page, however if a `+' is given before the URL, it will be treated as relative. For example, if the viewer is currently displaying http://www.foo.bar, if one enters ``/dir/file.html'', the display will be updated to /dir/file.html on the local machine. If instead one enters ``+/dir/file.html'', the display will be loaded with http://www.foo.bar/dir/file.html.
The HTTP capability imposes some obvious limitations on the string tokens which can be used in the help database. These keywords should not use the `/' character, or begin with a protocol specifier such as ``http:''.
HTML files on a local machine can be loaded by giving the full path name to the file. Relative references will be found. HTML files will also be found if they are located in the help path, however relative references will be found only if the referenced file is also in the help path. If a directory is referenced rather than a file, a formatted list of the files in the directory is shown.
If a filename passed to the viewer has one of the following extensions, the text is shown verbatim. The (case insensitive) extensions for plain-text files are ``.txt'', ``.log'', ``.scr'', ``.sh'', ``.csh'', ``.c'', ``.cc'', ``.cpp'', ``.h'', ``.py'', ``.tcl'', and ``.tk''.
In the WRspice help system, link references to files with a ``.cir'' extension will be sourced into WRspice when the link is clicked on. Thus, if one has a circuit file named ``mycircuit.cir'', and the HTML text in the help window contains a reference like
<a html="mycircuit.cir">click here</a>then clicking on the ``click here'' tag will source mycircuit.cir into WRspice. Similarly, link references to files with a ``.raw'' extension will be loaded into WRspice (as a rawfile, i.e. a plot data file) when the anchor is clicked.
This feature may solve a big problem. How many WRspice users have directories full of old simulation files, the details about which are long forgotton or buried in some notebook somewhere? Now the documentation task may be somewhat simpler. While doing simulations, one can maintain a text file containing notes about the circuit and results, with HTML anchor tags to the actual circuit and data files. Then, one can load the text file into the WRspice help system (if the notes are in a file ``notes.html'', one just types ``help notes.html''), and browse the notes and have one-click access to the original files and plot data. The notes file need not contain any other HTML constructs besides the anchor references.
Holding Shift while clicking on an anchor that points to a URL which specifies a file on a remote system will download the file. Downloading makes use of the httpget utility program available in the Accessories distribution. Installation of the accessories is required for downloading to be available under Unix/Linux. References to files with extensions ``.rpm'', ``.gz'', and other common binary file suffixes will automatically cause downloading rather than viewing. When downloading, the file selection pop-up will appear, pre-loaded with the file name (or ``http_return'' if the name is not known) in the current directory. One can change the saved name and the directory of the file to be downloaded. Pressing the Download button will start downloading. A pop-up will appear that monitors the transfer, which can be aborted with the Cancel button.