Calculator

Figure  is an example that emphasizes xtpanel's ability to take advantage of the many powerful but non-interactive features built into UNIX. The bc calculator built into UNIX has most of the features of a standard scientific calculator. But it lacks a nice interactive interface. The X windows source distributed by MIT contains an interactive calculator xcalc. Written in C, xcalc is over 2000 lines long, and doesn't take advantage of the calculator already available in UNIX. The xtpanel script uses the bc calculator and provides an interface similar to that of xcalc. The script is 80 lines long, and available on the CD-ROM version of the report.

 

calculator Figure 13 A calculator built using xtpanel. The 80 line script gives a calculator with features comparable to the 2000 line C program xcalc.

It is likely that this 80 line script required much less time to write than the xcalc application. And because the script syntax is very simple, adding features to this calculator would be a much easier task than adding features to xcalc.