System() for compiling c file

[roy17]

Hi,

I was doing a compilation of c file in wamp server
I use

 if ((move_uploaded_file($_FILES['compiledfile']['tmp_name'], $newname))) {
                $source = 'upload\\' . $_FILES['compiledfile']['name'];
                //echo $source;
                $destination = 'upload\\' . pathinfo($_FILES['compiledfile']['name'], PATHINFO_FILENAME) . '.exe';
                //echo $destination;
                $output = system('"C:\Program Files\CodeBlocks\MinGW\bin\gcc.exe" ' . $source . ' -O3 -o ' . $destination);
                echo $output;

which has been working correctly.

I decided to migrate to an ubuntu server
I have installed all the component from apache, php, mysql, and phpmyadmin.
I also install a codeblock for gcc compiler.
Then I try to correct the path as ubuntu use / not \ like windows.
However, I can't find what is wrong.
Below is my code

if ((move_uploaded_file($_FILES['compiledfile']['tmp_name'], $newname))) {
                $source = 'upload\\' . $_FILES['compiledfile']['name'];
                //echo $source;
                $destination = 'upload\\' . pathinfo($_FILES['compiledfile']['name'], PATHINFO_FILENAME) . '.exe';
                //echo $destination;
                $output = system('"/usr/bin/gcc-4.5.executable" ' . $source . ' -O3 -o ' . $destination);
                echo $output;

I already set the permission from root so I can create and delete the file inside the bin folder (where gcc is installed) and do the same thing for the upload folder inside my webroot.
What am I missing?

I try using $returnvalue after the command string

 $output = system('"/usr/bin/gcc-4.5.executable" ' . $source . ' -O3 -o ' . $destination,$returnvalue);
                echo $output;
echo $returnvalue;

However, the output if I upload a syntax error file is 1 which is not helping me to know what is the problem. How can I output the text error that usually appear under your command in the ubuntu terminal or windows command line in order to know what is wrong with my $output?

Thanks in advance🙂

[anoopmail]

Debug first to find out the problem is with permission or with the command line execution. eg: Try to execute a hard coded command line first. Make sure safe mode is not enabled.

[Ashley_Sheridan]

Is /usr/bin/gcc-4.5.executable reallythe executable? Typically, it is just /usr/bin/gcc. Is this something you installed yourself?

I already set the permission from root so I can create and delete the file inside the bin folder

this isn't particularly safe, you would be better off compiling the stuff in a different location, like a home directory. Also, when you said you set the permissions, what did you actually set? Did you change the user and/or group, or did you just blast it with read/write permissions for everyone?

As anoopmail said, you should first try seeing if the command you're executing actually works on its own. Echo out the string you're attempting to execute, and see if that runs in in your Linux box from the same directory as this script.

[roy17]

@
Thanks for your suggestion. I managed to get it running now.
Below is the working code

$source = '/var/www/upload/' . $_FILES['compiledfile']['name'];
$destination = '/var/www/upload/' . pathinfo($_FILES['compiledfile']['name'], PATHINFO_FILENAME) . '.exe';
$output = system('"/usr/bin/gcc-4.5" ' . $source . ' -O3 -o ' . $destination);

Is /usr/bin/gcc-4.5.executable reallythe executable?

No, that's why I open this thread as before I don't understand how to run the gcc in ubuntu.🙂

I installed codeblocks in ubuntu server and I use the compiler installed to compile the c file.

Also, when you said you set the permissions, what did you actually set?

I use the command

gksudo nautilus

I set the group and user to be able to create and delete files as I am not sure where the problem lies when I try to compile the file.
Is this bad practice? Is it better to use your read/write? If so, how can I do that?

you would be better off compiling the stuff in a different location, like a home directory.

What do you mean by this? The c file and the exe file to be put inside home directory? or the compiler inside home directory? As currently the compiler is inside bin under user while the c file is inside the web root. (var/www folder)

I also need to ask how can I produce an output like you usually see if there is a compilation error? (Those comments that appear below your comment if the command in the command line or terminal is wrong or if there is something wrong with your c file code, the error message will show right)
I try using the return value after the system(), however it only produce 1 or 0 which is not helping me if I want to show the error inside the c file code.
Thanks in advance.

[Ashley_Sheridan]

As you're compiling on an Ubuntu system, it won't create an exe file (not in the true sense) because it is compiling it for the Linux architecture, so it won't run on a Windows machine.

The gcc executable is usually at /usr/bin/gcc, just that, no extension or version number.

Running

gksudo nautilus

won't do anything other than open the Nautilus file browser as the root user. If you've set the user and group permissions, make sure that the files belong to the right user and/or group. By default that directory will be owned by the root user and group, and a PHP script using exec() will be running as the Apache user, which is usualyl something like wwwrun, www2, or apache. You'll need to find that out and set the various settings accordingly. It's not recommended to set 777 permissions, as this is very insecure.

[roy17]

As you're compiling on an Ubuntu system, it won't create an exe file (not in the true sense) because it is compiling it for the Linux architecture, so it won't run on a Windows machine.

Yes, I agree with this. I try to download the file and run it in windows. It can't be run on windows. If I try to run it, it produce some error which I can conclude as a corrupt file.

it's probably best to stick with '/usr/bin/gcc'

Actually, at first, I intended to stick with the gcc. However, in the detail of gcc inside ubuntu. The type is not executable but a link which I don't think will work. Hence right now, I am sticking with gcc-4.5 which can produce the output file which I want.

Sorry, for asking in this thread, all over again. Is it possible to get the error message which is usually produced when your c file has some error?
Meaning those error that say which line is wrong, etc.
I would like to have those error maybe stored inside a variable or inside a text file and produced it to the web page?
Are there any suggestion on how to put that to the variable or text file using system()?
😕
Thanks in advance.