xspread

The program xspread, shown in Figure 22.8, is a public domain spreadsheet that runs under X Windows. It’s installed with the Slackware distribution, and you must be using an X Windows terminal to be able to run this program. (The creators of xspread are working on making it use the ASCII screen if it can’t find an X Windows display to use.) The xspread Reference Manual gives complete documentation for the program. The LaTeX source copy for this manual is in the file xspread.tex.

Fig. 22.8  xspread under XFree86 provides familiar spreadsheet capabilities for Linux users.

xspread supports many standard spreadsheet features, including the following:

•  Cell entry and editing

•  Worksheet size of 2202 columns with unlimited rows

•  File reading and writing

•  File encryption

•  Absolute and relative cell references

•  Numeric and label (that is, character string) data in cells

•  Left or right justification for labels

•  Row and column insertion and deletion

•  Hiding and unhiding of rows and columns

•  Range names

•  Manual or automatic recalculation

•  Numeric operators (+, -, *, /, ^, %)

•  Relational operators (<, <=, >, >=, =, !=)

•  Logical (or Boolean) operators (&, |, ~)

•  Function references

•  Graphs (XY, bar, stack bar, pie, and line graphs)

•  Matrix operations (transpose, multiply, add, subtract, and inversion)

•  Cursor positioning with mouse

•  Menu item selection with mouse

•  References to external programs, which are called external functions

The structure and operation of the spreadsheet is similar to—but not identical with—popular spreadsheets such as Lotus 1-2-3 and its clones. Like other spreadsheets, the workspace is arranged into rows and columns of cells. Each cell can contain a number, a label, or a formula that evaluates to a number or label.

You can start the program with or without specifying a file to be read. This file must be a saved worksheet. If a file is specified on the command line, xspread attempts to locate and read the file. If it’s successful, xspread starts with the file’s contents in the workspace. If it’s unsuccessful or no file is specified on the command line, xspread starts with the workspace empty.

For a tutorial of the spreadsheet program, run one of the demo files—demo, demo_math, or demo_matrix—and see the file Sample_Run in the doc directory.

Seyon

Seyon, as shown in Figure 22.9, is a complete full-featured telecommunications package for the X Windows system. Some of its features are listed here and are described in detail in the next sections:

•  A dialing directory

•  Terminal emulation

•  A scripting language

•  A variety of download protocols, including Zmodem

•  Various translation modes

Dialing Directory

The dialing directory supports an unlimited number of entries. The directory is fully mouse-driven and features call-progress monitoring, dial timeout, automatic redial, multinumber dialing, and a circular redial queue. Each item in the dialing directory can be configured with its own baud rate, bit mask, and script file. The dialing directory uses a plain ASCII text phone book that you can edit from within Seyon. Seyon also supports manual dialing.

Terminal Emulation

Terminal emulation supports DEC vt102, Tektronix 4014, and ANSI. Seyon delegates its terminal emulation to xterm, so all the familiar xterm functions—such as the scroll-back buffer, cut-and-paste utility, and visual bell—are available through Seyon’s terminal emulation window.

Fig. 22.9  Although accessing the Internet is important today, many users still need access to bulletin boards via their modems.

Using xterm also means that Seyon has a more complete emulation of vt102 than any other UNIX or DOS telecommunications program. You also can use other terminal emulation programs with Seyon to suit the user’s need; for example, color xterm can be used to provide emulation for color ANSI (popular on many BBS systems), and xvt can be used if memory is a bit tight.

Scripting Language

You can use scripting language to automate tedious tasks such as logging in to remote hosts. Seyon’s script interpreter uses plain-text files and has a syntax similar to that of sh, with a few extra additions. It supports many familiar statements such as conditional branching by if...else and looping by goto. Scripts may be assigned to items in the dialing directory for automatic execution after a connection is made.

gFile Transfers

Seyon supports an unlimited number of slots for external file transfer protocols. Protocols are activated from a mouse-driven transfer console that uses a plain ASCII text file, editable from within Seyon, for protocol configuration. Seyon prompts the user for file names only if the chosen protocol requires filenames or if the transfer operation is an upload for which Seyon also accepts wildcards. Multiple download directories can be specified for the different transfer slots.

Seyon detects incoming Zmodem signatures and automatically activates a user-specified Zmodem protocol to receive incoming files. Zmodem transfers are thus completely automatic and require no user intervention.

Translation Modes

Seyon can perform useful translations with the user’s input. For example, Seyon can translate <Backspace> to <Delete>, a new-line marker to a carriage-return marker, and meta-key translation—that is, you can switch your <Esc> meta key to the <Alt> key. The latter mode simulates the meta key on hosts that don’t support 8-bit-clean connections and makes possible the use of the meta key in programs like emacs.

Other Seyon Features

Seyon allows you to interactively set program parameters, online help, software (XONN/XOFF) and hardware (RTS/CTS) flow control; capture a session to a file; and temporarily run a local shell in the terminal emulation window.

Seyon is intended to be simple yet extensively configurable. Almost every aspect of Seyon can be configured via the built-in resources to suit the user’s taste.