Question

I am using PHP on Windows machin. I also use Dev C++. I can perfectly compile .cpp file on CMD using this command:

g++ hello.cpp -O3 -o hello.exe

Now what I am trying to do is running the same command using php system() function, so it looks like this:

system(“g++ c:\wamp\www\grader\hello.cpp -O3 -o C:\wamp\www\grader\hello.exe”);

but it doesn’t compile. I am lost, please tell me what am I missing?

I also looked up at this question and thats exactly what I need, but I couldnt find a usefull solution for my case there:

Php script to compile c++ file and run the executable file with input file

Answer 1

Two things:

1. You are using double quotes and are not escaping the \ inside the path.
2. You are not using a full path to g++.

The first one is important as \ followed by something has a special meaning in such a string (you might know \n as new line), the second one is relevant since the PHP environment might have a different search path.

A solution might be

system("c:\\path\\to\\g++ c:\\wamp\\www\\grader\\hello.cpp -O3 -o C:\\wamp\\www\\grader\\hello.exe");

Alternatively you can use single quotes, intead of double quotes, they use diffeent,less strict escaping rules

system('c:\path\to\g++ c:\wamp\www\grader\hello.cpp -O3 -o C:\wamp\www\grader\hello.exe');

or use / instead of \, which is supported by windows, too.

system("c:/path/to/g++ c:/wamp/www/grader/hello.cpp -O3 -o C:/wamp/www/grader/hello.exe");

What you do is your choice, while many might consider the first one as ugly, and the last one as bad style on Windows 😉