A stronger C/C++ Preprocesser
Ever felt you needed some preprocessing to generate some C/C++ code for you, but the C preprocesssor is too lacking? Say for example you wanted to include part of another file, or include output from an application. Perhaps the compile should be based on some data found on a remote server? Well, there are stronger preprocessors which work for C/C++, such as PHP.
Here's an example:
Here's a more interesting example:
/tmp> php test.cpp.php | g++ -x c++ -Wall -o test -
/tmp> ./test
Hello 0
Hello 1
Hello 2
Hello 3
Hello 4
/tmp> cat test.cpp.php
#include <iostream>
int main()
{
<?php for ($i = 0; $i < 5; ++$i) { echo 'std::cout << "Hello ', $i, '" << std::endl;'; } ?>
return(0);
}
/tmp>
/tmp> php weather_example.c.php | gcc -x c -Wall -o weather_example -
/tmp> ./weather_example
Hi, when I was compiled, the weather here in New York City was 57F
/tmp> cat weather_example.c.php
<?php
$w = file_get_contents('http://www.google.com/ig/api?weather=New+York+City');
$f = '<temp_f data="';
echo '#define __WEATHER__ ', (int)substr($w, strpos($w, $f)+strlen($f)), 'U', "\n";
?>
#include <stdio.h>
int main()
{
printf("Hi, when I was compiled, the weather here in New York City was %uF\n", __WEATHER__);
return(0);
}
/tmp>
0 comments:
Post a Comment