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This based on a example i found at http://www.cs.tut.fi/~jkorpela/
forms/cgic.html

#include <fcgi_stdio.h>
#include <stdlib.h>

int urldecode(char *src, char *last, char *dest){
int code;
for (; src != last; src++, dest++){
if (*src == '+') *dest = ' ';
else if(*src == '%') {
if(sscanf(src+1, "%2x", &code) != 1) code = '?';
*dest = code;
src +=2;
}
else *dest = *src;
}
*dest = '\n';
*++dest = '\0';
return 0;
}

int post(char *output){
char *lenstr=getenv("CONTENT_LENGTH");
char *input;
long len;
if (lenstr != NULL && sscanf(lenstr, "%ld", &len) == 1) {
fgets(input, len+1, stdin);
urldecode(input, input+len, output);
}
return 0;
}

int main (void){
char *output;
while (FCGI_Accept() >= 0) {
post(output);
printf("Content-Type: text/xml; charset=utf-8"
"\r\n"
"\r\n"
"%s"
"\n"
,output);
}
return 0;
}

The only thing i did is simplified it a bit so i could understand it a
bit better. The goal is to read the post from a xmlhttprequest and
return its contents back.

So far i receive the post but the urldecoding seems not to play along
and scrambles the output, any suggestions ?

On Feb 13, 12:31 am, "gert" <gert.cuyk...@gmail.com> wrote:
> This based on a example i found athttp://www.cs.tut.fi/~jkorpela/
> forms/cgic.html
>
> #include <fcgi_stdio.h>
> #include <stdlib.h>
>
> int urldecode(char *src, char *last, char *dest){
> int code;
> for (; src != last; src++, dest++){
> if (*src == '+') *dest = ' ';
> else if(*src == '%') {
> if(sscanf(src+1, "%2x", &code) != 1) code = '?';
> *dest = code;
> src +=2;
> }
> else *dest = *src;
> }
> *dest = '\n';
> *++dest = '\0';
> return 0;
>
> }
>
> int post(char *output){
> char *lenstr=getenv("CONTENT_LENGTH");
> char *input;
> long len;
> if (lenstr != NULL && sscanf(lenstr, "%ld", &len) == 1) {
> fgets(input, len+1, stdin);
> urldecode(input, input+len, output);
> }
> return 0;
>
> }
>
> int main (void){
> char *output;
> while (FCGI_Accept() >= 0) {
> post(output);
> printf("Content-Type: text/xml; charset=utf-8"
> "\r\n"
> "\r\n"
> "%s"
> "\n"
> ,output);
> }
> return 0;
>
> }
>
> The only thing i did is simplified it a bit so i could understand it a
> bit better. The goal is to read the post from a xmlhttprequest and
> return its contents back.
>
> So far i receive the post but the urldecoding seems not to play along
> and scrambles the output, any suggestions ?

better do it like this i think

if (lenstr != NULL ) {
sscanf(lenstr, "%ld", &len)
fgets(input, len+1, stdin);
urldecode(input, input+len, output);
}

still scrambely doh ?

gert wrote:
> This based on a example i found at http://www.cs.tut.fi/~jkorpela/
> forms/cgic.html
>
<snip code>
>
> The only thing i did is simplified it a bit so i could understand it a
> bit better. The goal is to read the post from a xmlhttprequest and
> return its contents back.
>
> So far i receive the post but the urldecoding seems not to play along
> and scrambles the output, any suggestions ?
>
Write some tests in order to understand how the code works.

--
Ian Collins.

gert wrote:

> This based on a example i found at http://www.cs.tut.fi/~jkorpela/
> forms/cgic.html
>
> #include <fcgi_stdio.h>
> #include <stdlib.h>
>
> int urldecode(char *src, char *last, char *dest){
> int code;
> for (; src != last; src++, dest++){
> if (*src == '+') *dest = ' ';
> else if(*src == '%') {
> if(sscanf(src+1, "%2x", &code) != 1) code = '?';
> *dest = code;
> src +=2;
> }
> else *dest = *src;
> }
> *dest = '\n';
> *++dest = '\0';
> return 0;
> }

I had written something similar for a toy cgi form util I did a while back...
It's not super well checked for errors, but I do remember it atleast working.

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

struct cgi_var__ {
char *key;
char *val;
size_t key_l;
size_t val_l;
};

static int form_decode(cgi_var *cv, size_t off)
{
char c, tmp[4];
int r;

if (cv->val[off] != '%') {
fprintf(stdout, "form_decode: bad value\n");
return -1;
}

if ((r = (cv->val + cv->val_l) - (cv->val + off)) < 3) {
fprintf(stdout, "form_decode: length too short\n");
return -1;
}

memcpy(tmp, cv->val + off, MIN(3, r)); tmp[3] = '\0';
c = (unsigned char)strtol(tmp + 1, NULL, 16);

/*
* data == text%7Cj%25%5C%25
* 01234567890123456
*
* c == |, off == 4, r == 13
* c == %, off == 6, r == 9
* c == \, off == 7, r == 6
* c == %, off == 8, r == 3
*/

memcpy(cv->val + off, &c, sizeof c);
memmove(cv->val + off + 1, cv->val + off + 3, r - 3);

cv->val_l -= 2;
r = (cv->val + cv->val_l) - (cv->val + off);

return 0;
}

static int cv_filter(cgi_var *cv)
{
size_t i;

/* filter out rug-rats or decode %xx */
for (i = 0; i < cv->val_l; i++) {
if (cv->val[i] == '%')
form_decode(cv, i);
switch (cv->val[i]) {
case '+': case '\'': case '`': case '"':
cv->val[i] = ' '; break;
default: break;
}
}

return 0;
}

On Feb 13, 12:31 am, "gert" <gert.cuyk...@gmail.com> wrote:
> This based on a example i found athttp://www.cs.tut.fi/~jkorpela/
> forms/cgic.html
>
> #include <fcgi_stdio.h>
> #include <stdlib.h>
>
> int urldecode(char *src, char *last, char *dest){
> int code;
> for (; src != last; src++, dest++){
> if (*src == '+') *dest = ' ';
> else if(*src == '%') {
> if(sscanf(src+1, "%2x", &code) != 1) code = '?';
> *dest = code;
> src +=2;
> }
> else *dest = *src;
> }
> *dest = '\n';
> *++dest = '\0';
> return 0;
>
> }
>
> int post(char *output){
> char *lenstr=getenv("CONTENT_LENGTH");
> char *input;
> long len;
> if (lenstr != NULL && sscanf(lenstr, "%ld", &len) == 1) {
> fgets(input, len+1, stdin);
> urldecode(input, input+len, output);
> }
> return 0;
>
> }
>
> int main (void){
> char *output;
> while (FCGI_Accept() >= 0) {
> post(output);
> printf("Content-Type: text/xml; charset=utf-8"
> "\r\n"
> "\r\n"
> "%s"
> "\n"
> ,output);
> }
> return 0;
>
> }
>

My test tool doesnt work segmant fault, something to do with
stdin ???

#! /bin/sh
gcc -I /usr/local/include/ -L /usr/local/lib/ -l fcgi -o /home/gert/
Desktop/svn/db/bin/c /home/gert/Desktop/svn/db/bin/c.c
env CONTENT_LENGTH=3 /home/gert/Desktop/svn/db/bin/c << "test"

gert wrote:

>> char *input;
>> long len;
>> if (lenstr != NULL && sscanf(lenstr, "%ld", &len) == 1) {
>> fgets(input, len+1, stdin);

Uhh, fgets() needs a valid buffer to be writing into. You're just giving it a
pointer to an undefined location. Nothing has been allocated for it. There
are more basic things that need to be solved before you can approach even
getting your code to do what it is you want it to do.

On Feb 14, 6:24 am, Christopher Layne <cla...@com.anodized> wrote:
> gert wrote:
> >> char *input;
> >> long len;
> >> if (lenstr != NULL && sscanf(lenstr, "%ld", &len) == 1) {
> >> fgets(input, len+1, stdin);
>
> Uhh, fgets() needs a valid buffer to be writing into. You're just giving it a
> pointer to an undefined location. Nothing has been allocated for it. There
> are more basic things that need to be solved before you can approach even
> getting your code to do what it is you want it to do.

And there goes my plans for the weekend
Better start with valid buffer then, this part came straight from the
example at http://www.cs.tut.fi/~jkorpela/forms/cgic.html

fgets(input, len+1, stdin);

Any other full cgi post examples please ?

gert wrote, On 14/02/07 19:40:
> On Feb 14, 6:24 am, Christopher Layne <cla...@com.anodized> wrote:
>> gert wrote:
>>>> char *input;
>>>> long len;
>>>> if (lenstr != NULL && sscanf(lenstr, "%ld", &len) == 1) {
>>>> fgets(input, len+1, stdin);
>> Uhh, fgets() needs a valid buffer to be writing into. You're just giving it a
>> pointer to an undefined location. Nothing has been allocated for it. There
>> are more basic things that need to be solved before you can approach even
>> getting your code to do what it is you want it to do.
>
> And there goes my plans for the weekend
> Better start with valid buffer then, this part came straight from the
> example at http://www.cs.tut.fi/~jkorpela/forms/cgic.html
>
> fgets(input, len+1, stdin);

That specific line does, but the definition of input is different. You
have defined it as a pointer to char, the code at that URL defines it as
a char array.

> Any other full cgi post examples please ?

I don't, but I suggest you start looking at the comp.lang.c FAQ (Google
will find it) and buy a copy of K&R2 (the full details are in the
bibliography of the FAQ). Then you can start learning C properly since
you need to know the language in order to write CGIs in it.
--
Flash Gordon

#include <fcgi_stdio.h>
#include <stdlib.h>

int urldecode(char *src, char *last, char *dest){
int code;
for (; src != last; src++, dest++){
if (*src == '+') *dest = ' ';
else if(*src == '%') {
if(sscanf(src+1, "%2x", &code) != 1) code = '?';
*dest = code;
src +=2;
}
else *dest = *src;
}
*dest = '\n';
*++dest = '\0';
return 0;
}

int post(void){
char input[100];
char *lenstr;
long len;
lenstr=getenv("CONTENT_LENGTH");
if (lenstr != NULL && sscanf(lenstr,"%ld",&len)==1 ) {
fgets(input, len+1, stdin);
//urldecode(input, input+len, input);
printf("Content-Type: text/xml; charset=utf-8"
"\r\n"
"\r\n"
"<xml>%s %d</xml>"
"\n"
,input,len);
}
return 0;
}

int main (void){
char * input;
while (FCGI_Accept() >= 0) {
post();
}
return 0;
}

So far this works thx to flash gorden pointing out the char pointer

Can somebody explain why char * instead of [] only let me post 11
characters ? 12 characters equals segfault ?

my tool still displays hebrew doh but at least it doesnt give me a
segfault ?

#! /bin/sh
gcc -I /usr/local/include/ -L /usr/local/lib/ -l fcgi -o /home/gert/
Desktop/svn/db/bin/c /home/gert/Desktop/svn/db/bin/c.c
sudo /etc/init.d/lighttpd restart
env CONTENT_LENGTH=3 /home/gert/Desktop/svn/db/bin/c << "test" << EOF

gert@gert:~$ Desktop/svn/db/bin/make.sh
* Stopping web server
lighttpd [ ok ]
* Starting web server
lighttpd [ ok ]
Content-Type: text/xml; charset=utf-8

<xml>x+5?++ 3</xml>
gert@gert:~$

On Feb 15, 12:32 am, "gert" <gert.cuyk...@gmail.com> wrote:
> #include <fcgi_stdio.h>
> #include <stdlib.h>
>
> int urldecode(char *src, char *last, char *dest){
> int code;
> for (; src != last; src++, dest++){
> if (*src == '+') *dest = ' ';
> else if(*src == '%') {
> if(sscanf(src+1, "%2x", &code) != 1) code = '?';
> *dest = code;
> src +=2;
> }
> else *dest = *src;
> }
> *dest = '\n';
> *++dest = '\0';
> return 0;
>
> }
>
> int post(void){
> char input[100];
> char *lenstr;
> long len;
> lenstr=getenv("CONTENT_LENGTH");
> if (lenstr != NULL && sscanf(lenstr,"%ld",&len)==1 ) {
> fgets(input, len+1, stdin);
> //urldecode(input, input+len, input);
> printf("Content-Type: text/xml; charset=utf-8"
> "\r\n"
> "\r\n"
> "<xml>%s %d</xml>"
> "\n"
> ,input,len);
> }
> return 0;
>
> }
>
> int main (void){
> char * input;
> while (FCGI_Accept() >= 0) {
> post();
> }
> return 0;
>
> }
>
> So far this works thx to flash gorden pointing out the char pointer
>
> Can somebody explain why char * instead of [] only let me post 11
> characters ? 12 characters equals segfault ?

Never mind i think i know why after reading Christopher Layne and
Flash Gordon answers a few times.

fgets just need some memory, not a pointer. PS can i make the []
dynamic with the sizeof the post without using maloc ?

> my tool still displays hebrew doh but at least it doesnt give me a
> segfault ?
>
> #! /bin/sh
> gcc -I /usr/local/include/ -L /usr/local/lib/ -l fcgi -o /home/gert/
> Desktop/svn/db/bin/c /home/gert/Desktop/svn/db/bin/c.c
> sudo /etc/init.d/lighttpd restart
> env CONTENT_LENGTH=3 /home/gert/Desktop/svn/db/bin/c << "test" << EOF
>
> gert@gert:~$ Desktop/svn/db/bin/make.sh
> * Stopping web server
> lighttpd [ ok ]
> * Starting web server
> lighttpd [ ok ]
> Content-Type: text/xml; charset=utf-8
>
> <xml>x+5?++ 3</xml>
> gert@gert:~$

Still want to know about my tool that speak some foreign language "x+5?
++ 3" what ever that means or sound like

If you people dont mind telling me or point something out ?