Get CPU frequency (Linux platforms - /proc/cpuinfo)

cpu_freq

#include <iostream>
#include <fstream>
#include <string>
#include <stdint.h>
#include <pcre.h>

using namespace std;

uint32_t cpufreq()
{
    uint32_t cpuFreq = 0;

    // CPU frequency is stored in /proc/cpuinfo in lines beginning with "cpu MHz"
    string pattern = "^cpu MHz\\s*:\\s*(\\d+)";
    const char* pcreErrorStr = NULL;
    int pcreErrorOffset = 0;

    pcre* reCompiled = pcre_compile(pattern.c_str(), PCRE_ANCHORED, &pcreErrorStr,
                                    &pcreErrorOffset, NULL);
    if(reCompiled == NULL)
    {
	return 0;
    }

    ifstream ifs("/proc/cpuinfo");
    if(ifs.is_open())
    {	
	string line;
	int results[10];

	while(ifs.good())
	{
	    getline(ifs, line);
	    int rc = pcre_exec(reCompiled, 0, line.c_str(), line.length(), 
                               0, 0, results, 10);
	    if(rc < 0)
		continue;

	    // Match found - extract frequency
	    const char* matchStr = NULL;
	    pcre_get_substring(line.c_str(), results, rc, 1, &(matchStr));
	    cpuFreq = atol(matchStr);
	    pcre_free_substring(matchStr);
	    break;
	}
    }
    
    ifs.close();
    pcre_free(reCompiled);

    return cpuFreq;
}


int main()
{
    cout << "CPU Frequency = " << cpufreq() << " MHz" << endl;
    return 0;
}