#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#define ishex(x) (((x) >= '0' && (x) <= '9') || ((x) >= 'a' &&
(x) <= 'f') || ((x) >= 'A' && (x) <= 'F'))
int htoi(char *s) {
int value;
char c;
c = s[0];
if(isupper(c)) c = tolower(c);
value=(c >= '0' && c <= '9' ? c - '0' : c - 'a' + 10) * 16;
c = s[1];
if(isupper(c)) c = tolower(c);
value += c >= '0' && c <= '9' ? c - '0' : c - 'a' + 10;
return(value);
}
void main(int argc, char *argv[]) {
char *params, *data, *dest, *s, *tmp;
char *name, *age;
puts("Content-type: text/html\r\n");
puts("<html><head><title>Form Example</title></head>");
puts("<body><h1>My Example Form</h1>");
puts("<form action=\"form.cgi\" method=\"GET\">");
puts("Name: <input type=\"text\" name=\"name\">");
puts("Age: <input type=\"text\" name=\"age\">");
puts("<br><input type=\"submit\">");
puts("</form>");
data = getenv("QUERY_STRING");
if(data && *data) {
params = data; dest = data;
while(*data) {
if(*data=='+') *dest=' ';
else if(*data == '%' && ishex(*(data+1))&&ishex(*(data+2))) {
*dest = (char) htoi(data + 1);
data+=2;
} else *dest = *data;
data++;
dest++;
}
*dest = '\0';
s = strtok(params,"&");
do {
tmp = strchr(s,'=');
if(tmp) {
*tmp = '\0';
if(!strcmp(s,"name")) name = tmp+1;
else if(!strcmp(s,"age")) age = tmp+1;
}
} while(s=strtok(NULL,"&"));
printf("Hi %s, you are %s years old\n",name,age);
}
puts("</body></html>");
}
