problem with program execution (g++)

[kavent]

Hi everyone, I am new to PHP and trying to do something as the following:
Allow users to enter their c++ code in text area, which will be saved in main.cpp.
Then I tried to run g++ (from /usr/bin/g++) to compile this main.cpp, but nothing happened. It seems that I can't run other programs in /usr/bin/ either.

<?php
$cmd = "less main.cpp; g++ main.cpp -o test.out;";
echo shell_exec($cmd);
?>

shows main.cpp with no problem, but it doesn't compile. g++ has permission of 755, safe_mode is off, and I don't have root on the server.

Any help would be appreciated. Thanks!

[btherl]

Try

[code=php:0]$cmd = "less main.cpp; g++ main.cpp -o test.out &> /tmp/g++.out;";[/code]


And see what you get in /tmp/g++.out

It might help to give the full path too, [code=php:0]/usr/bin/g++ main.cpp[/code]

[kavent]

It does work, thanks!
However, I don't quite understand the syntax "&> /tmp/g++.out;". Actually, what I tried to do is to use a application called dot, which is similar to g++, to compile DOT file. The commend looks like this:

$cmd = "dot test.dot -Tsvg -o test.svg;";

Would you help me with this one as well? Thank you!