Month
Month
Summary by: Ron Murawski (the_murs@pipeline.com)
C/C++ User Group
The C/C++ User Group meets on the third Tuesday of every month. The April meeting began with a discussion of the Trenton Computer Festival (TCF) which occurred on the previous weekend. Members confessed to buying items such as a 56K modem and a 24x CD. TCF always offers tremendous bargains on computer equipment, especially at the fleamarket.
Bruce Arnold spent some time discussing the BeOS, a new operating system that runs on PCs. Bruce's first impression is that it seems small, fast and efficient. It also comes with a C compiler and Bruce promised a future report.
One member was programming in Windows and had trouble trying to launch a new window from a dialogue box. A knowledgeable member, James Carr, suggested that sub-classing the window in such a way as make it look like a control would solve the problem.
An interesting program was shown: A DOS program containing Win API calls to create a graphical window. The program displayed an attractive Mandelbrot plot. The C source code was included and was surprisingly small.
Bruce then moved on to the main presentation, a DOS program to address an envelope and print a bar code representing the zipcode. The program is notable for several features:
1. Direct control of a laser printer using PCL commands.
2. A "visual" version to display onscreen the envelope appearance.
Bruce essentially wrote two programs, one to send output to a laser printer and one to send output to a monitor. He used a compartmentalized approach so all common code resides in a common file. The bar coding conforms to US Postal Service regulations. The program is written in C in a straight-forward manner with helpful comments thoughout. You can get the source code and the executable programs from links on Bruce's C User Group home page: The source code and executables are avialable directly from the ACGNJ ftp server:
See SOURCE CODE links below.
// envsubs.c subroutines for envelope program. B.Arnold
//
// 12-19-1993
//
// This code is common to 'env.c' and 'etest.c'
//
// The following routine takes the last line of the destination address
// and attempts to find the zip code as the last token. It does this by
// reversing the line and looking for the first token. The token (if
// found) is then reversed back to its original order. It is passed to
// a validity checking routine to verify that it really is a zip code.
// If all is OK, the barcode graphics routine is called.
//
void do_barcode(char *lastline) // high level bar code parse routine
{ //
char *p, *line; // Note: postal
if (NULL == (line = strdup(lastline))) return; // regulations also
strrev(line); // allow adding the
p = strtok(line, ":;., \t\n\r"); // last 2 digits of
if (p==NULL) return; // the street address
strrev(p); // at the end of the
if ( valid(p) ) barcode(p); // zip code. Ei.,
free(p); // 08809-103612
}