I decided to revive my (many months) inactive site today using things I've learned about C++ CGI and the Document Object Model along with CSS. The site is still down, but I'm trying to get back into CGI after leaving it alone for a while (also months). I've spent the past three hours debugging this (90 minutes fixing late-night typos and a few missing semicolons, the rest spent trying to fix the problem described herein) but I can't get the function I'm basically writing it for to work. The (cgi::find) function.
This http://24.148.160.212/cgi-bin/test.cgi?cheese=cheese& is supposed to output:
cheese = cheese
I would like cheese today.
I also shouldn't need an & at the end of the query, but for some reason and hours of fiddling with my code to sort a query into variables and contents of those variables I still need the & at the end.
My server is running Apache 2.2.4 and on Windows XP and the code was compiled using Borland C++ 5.5.1 for Win32.
/*
A CGI tool allowing the use of form.find("input name") in scripts after running init()
example in main:
#include "cgi.cpp"
int main(int argc, char *argv[])
{
cgi form = init();
string cheese;
form.find( "cheese", cheese );
cout<<"<html>";
cout<<cheese;
cout<<"</html>";
}
would generate a page with the content of query or post input 'cheese' on it.
I don't know if my array use is secure or not, it supports a megabyte at the moment.
I'll begin optimization on return from vacation, any suggestions?
*/
//planned features:
//function 'text("filename")' outputs the file to a browser - can be used for blogs
//function 'cgi.record("name","filename")' puts the content of name at the end of file filename
#include <iostream>
#include <string>
#include <cstdlib>
using namespace std;
class cgi
{
friend cgi init();
private: string name; //post/query variable
string content; //contents of post/query variable
cgi *nextone; //nextone cgi. functions stop at NULL when searching for a certain name.
public: cgi(string n=" ", string c=" ") //initialize the cgi
{
name = n;
content = c;
nextone = NULL;
}
void reset(string n, string c) //reset the cgi
{
name = n;
content = c;
nextone = NULL;
}
void add(string n, string c) //add a variable to the end
{
if (nextone==NULL)
{
nextone = new cgi(n,c);
}
else
nextone->add(n,c);
}
bool find(string n, string &c) //find n, and if found, return true and copy n's content to c. if not, return false
{
if ( ! name.compare( n ) ) //if name is equal to n
{
c = content;
return true;
}
else if (nextone==NULL) //if this is the last element of the cgi
return false;
else //pass the find to the nextone
return nextone->find(n,c);
}
private: void convert()
{
int length = content.length();
int con; //content position
int nco=0; //new content position
string newcontent;
for (con = 0; con<length; con++)
{
if (content[con]=='%') //URL encoded, leave normally encoded things alone, convert what is safe to use in HTML
{
switch (content[con+1])
{
case '2':
switch (content[con+2])
{
case '0': newcontent[nco++]=' '; continue;
case '4': newcontent[nco++]='$'; continue;
case '6': newcontent[nco++]='&'; continue;
case 'b':
case 'B': newcontent[nco++]='+'; continue;
case 'c':
case 'C': newcontent[nco++]=','; continue;
case 'f':
case 'F': newcontent[nco++]='/'; continue;
default: newcontent[nco++] = '%';
newcontent[nco++] = content[con++];
newcontent[nco++] = content[con++];
continue;
}
con+=2;
nco++;
continue;
case '3':
switch (content[con+2])
{
case 'a':
case 'A': newcontent[nco++]=':'; continue;
case 'b':
case 'B': newcontent[nco++]=';'; continue;
case 'd':
case 'D': newcontent[nco++]='='; continue;
case 'f':
case 'F': newcontent[nco++]='?'; continue;
default: newcontent[nco++] = '%';
newcontent[nco++] = content[con++];
newcontent[nco++] = content[con++];
continue;
}
con+=2;
nco++;
continue;
case '4':
if (content[con+2]=='0')
newcontent[nco++]='@';
else
{
newcontent[nco++] = '%';
newcontent[nco++] = content[con++];
newcontent[nco++] = content[con++];
continue;
}
con+=2;
nco++;
continue;
default: newcontent[nco++] = '%';
newcontent[nco++] = content[con++];
newcontent[nco++] = content[con++];
continue;
}
}
else //if already plaintext
{
newcontent[nco] = content[con];
nco++;
}
}
newcontent[nco]='\0';
content = newcontent;
if (nextone!=NULL)
nextone->convert();
}
};
cgi init()
{
cgi raw; //before url unencoding
cgi plain; //after url unencoding
string query; //in case of query string
int length; //content length, if existent
int a; //integer variable
int b; //integer variable
string c; //string variable
string d; //string variable
char buffer[1024000]; //support a megabyte of form data
cout<<"Content-type: text/html\n\n"; //give the browser a heads up
if ( getenv( "QUERY_STRING" ) ) //if there is a query string
{
query = getenv( "QUERY_STRING" );
}
else if ( getenv( "CONTENT_LENGTH" ) )
{
length = atoi( getenv( "CONTENT_LENGTH") );
cin.read( buffer, length );
query = buffer;
}
else
{
cout<<"Content-type: text/html\n\n";
cout<<"No form input.";
}
//initialize the raw cgi
a = query.find_first_of('='); //find the end of the variable name
c = query.substr( 0 , a ); //assign c the variable name
b = query.find_first_of('&'); //find the end of the variable content
if (query.find_first_of('&') == -1 ) //if & not found
b = query.length();
d = query.substr( a+1 , b ); //assign d the variable content
query = query.substr( b+1, query.length() ); //shorten the query string accordingly
raw.reset( c, d );
cout<<c<<" = "<<d<<endl<<"<br>";
while (query.length()>1)
{
a = query.find_first_of('='); //find the end of the variable name
if (query.find_first_of('=') == -1) //there are no more variables
break;
c = query.substr( 0 , a ); //assign c the variable name
b = query.find_first_of('&'); //find the end of the variable content
if (query.find_first_of('&') == -1 ) //if & not found
b = query.length();
d = query.substr( a+1 , b ); //assign d the variable content
query = query.substr( b+1, query.length() ); //shorten the query string accordingly
raw.add( c, d ); //add to the cgi instead of resetting it
cout<<c<<" = "<<d<<"<br>";
}
//herein lies the conversion of all raw cgi content's to plaintext (not a grammatical error)
raw.convert();
plain = raw;
//herein lies the returning of the converted content goodness
return plain;
}
I had a blog, comment system, and forum working before, but that code was such a terrible mess (yes, worse than this) that I decided not to use it. Also, my previous code used RudeCGI which was difficult to cross-platform. I'm trying to write (at least) a platform-portable .cpp file allowing me to write programs that read form input from a browser and access the content of the form's inputs using form.find("inputname"), or better yet form["inputname"].
I'm finding it truer and truer that coding is small% writing and majority% debugging/maintenance.
Any suggestions, assistance, or tips on my rusty C++ coding style are appreciated.
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