Maximum string length that can be passed in command line argument? - c++

Question

I already saw this question similar ques for SQL
I am passing content of web page as argument to c++ program.
my code is here:
<?php
//sent has value "http://www.paulgraham.com/herd.html"
$url=$_POST['sent'];
$text = file_get_contents($url);
$temp=strip_tags($text);
$output=shell_exec("/home/technoworld/Videos/LinSocket/Modular/x '$temp'");
echo $output;
?>
Which gives output for small content only. Output I get is
most : 1 in : 1 investors : 1 component : 1 2013The : 1 biggest : 1 August : 1 Dynamics : 1 Herd : 1 Investor : 1 Maximum Occurrences Investor Herd Dynamics August 2013The biggest component in most investors
While actually it show gives count for each word.
Manually when I execute my program in command line:
./x "string"
It works and gives correct result for first paragraph of "http://www.paulgraham.com/herd.html"
. But it does not pass second and next para content in argument. It just write it on command line.
How can I pass such a content in argument? For small content it gives correct output.
getconf ARG_MAX
Argument list allowed for my system is : 2097152

Answer 1

I've changed your PHP program to use escapeshellarg as follows. I didn't test it, but my guess is that it will work
<?php
//sent has value "http://www.paulgraham.com/herd.html"
$url=$_POST['sent'];
$text = file_get_contents($url);
$temp=escapeshellarg(strip_tags($text));
$output=shell_exec("/home/technoworld/Videos/LinSocket/Modular/x " . $temp);
echo $output;
?>

Answer 2

You might modify the C++ and PHP sources and build a pipe.
C++
int main () {
std::ostringstream txt;
txt << std::cin.rdbuf();
std::cout << "Input: \n" << txt.str() << std::endl;
return 0;
}
PHP
<?php
$pipe = popen('Debug/Test', 'w');
if( ! $pipe) {
// Error
}
else {
$txt = 'Hello World';
fwrite($pipe, $txt, strlen($txt));
pclose($pipe);
}
?>