Solved

ercis

Posted on 2000-02-24
6
192 Views
Last Modified: 2010-04-02
Please answer this for your points.
0
Comment
Question by:rkcth
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3
6 Comments
 
LVL 22

Expert Comment

by:nietod
ID: 2556603
I believe this is for

http://www.experts-exchange.com/jsp/qShow.jsp?ta=cplusprog&qid=10299447 

correct?  (Always good to provide "justification".)
0
 
LVL 1

Accepted Solution

by:
ercis earned 50 total points
ID: 2559893
/***

this will do more: create 1x1 dot with specified color...
compile: gcc -Wall -s -o dot.cgi dot.c
and write in html:
 <img src="http://host.com/cgi-bin/dot.cgi?FF0000" width="50" height="5">

***/


#include <stdio.h>
#include <stdlib.h>

char x2c(char *what) {
   register char digit;
   digit = (what[0] >= 'A' ? ((what[0] & 0xdf) - 'A')+10 : (what[0] - '0'));
   digit *= 16;
   digit += (what[1] >= 'A' ? ((what[1] & 0xdf) - 'A')+10 : (what[1] - '0'));
   return(digit);
}

const unsigned char IMAGE_GIF1[] = {
   0x47, 0x49, 0x46, 0x38, 0x39, 0x61, 0x01, 0x00,
   0x01, 0x00, 0x80, 0xFF, 0x00, 0xFF, 0xFF, 0xFF };

const unsigned char IMAGE_GIF2[] = {
                     0x2C, 0x00, 0x00, 0x00, 0x00,
   0x01, 0x00, 0x01, 0x00, 0x00, 0x02, 0x02, 0x4C,
   0x01, 0x00, 0x3B };

int main(int argc, char *argv[])
{
   char *input, *p, *e;
   long l1 = sizeof(IMAGE_GIF1);
   long l2 = sizeof(IMAGE_GIF2);


   if( (p=getenv("REQUEST_METHOD")) && !strcmp(p, "GET") &&
       (p=getenv("QUERY_STRING")) && strlen(p) > 5 )
      input = p;
   else
      if(argc > 1 && strlen(argv[1]) > 5)  input = argv[1];
         else
            input = "ffffff";  // default = white

   printf("Content-type: image/gif\r\n");
   printf("Content-Length: %lu\r\n\r\n", l1 + 3 + l2);

   p = (char *)IMAGE_GIF1;
   e = p + l1;

   do
   {
     putchar(*p);
   }
   while (++p < e);

   putchar(x2c(input));
   putchar(x2c(input + 2));
   putchar(x2c(input + 4));

   p = (char *)IMAGE_GIF2;
   e = p + l2;

   do
   {
     putchar(*p);
   }
   while (++p < e);

   exit(0);
}

// nietod can make some optimizations :)
// maybe fwrite(IMAGE_GIF, sizeof(IMAGE_GIF), 1, stdout);
0
 
LVL 22

Expert Comment

by:nietod
ID: 2560921
Instead of

p = (char *)IMAGE_GIF1;
e = p + l1;

do
{
   putchar(*p);
}
while (++p < e);

I would just do

cout.write(IMAGE_GIF1,sizeof(IMAGE_GIF1));

it is simpler and likely to be faster.
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 1

Expert Comment

by:ercis
ID: 2562971
yes, but I'm talking about C, not C++
0
 
LVL 22

Expert Comment

by:nietod
ID: 2562994
But this is the C++ topic area.  We kill for less.  :-)
0
 
LVL 1

Expert Comment

by:ercis
ID: 2563462
nietod: sorry, I omited that :)
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
returning a dereferenced pts in C++ 10 167
Fast, free, private online code repository / editor 7 113
What is sub-make ? 2 88
print bytes of an integer 6 27
Written by John Humphreys C++ Threading and the POSIX Library This article will cover the basic information that you need to know in order to make use of the POSIX threading library available for C and C++ on UNIX and most Linux systems.   [s…
Introduction This article is the first in a series of articles about the C/C++ Visual Studio Express debugger.  It provides a quick start guide in using the debugger. Part 2 focuses on additional topics in breakpoints.  Lastly, Part 3 focuses on th…
The goal of the video will be to teach the user the concept of local variables and scope. An example of a locally defined variable will be given as well as an explanation of what scope is in C++. The local variable and concept of scope will be relat…
The viewer will learn additional member functions of the vector class. Specifically, the capacity and swap member functions will be introduced.

730 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question