HugePageSize.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <errno.h>
static inline uint64_t
rte_str_to_size(const char *str)
{
	char *endptr;
	unsigned long long size;

	while (isspace((int)*str))
		str++;
	if (*str == '-')
		return 0;

	errno = 0;
	size = strtoull(str, &endptr, 0);
	if (errno)
		return 0;

	if (*endptr == ' ')
		endptr++; /* allow 1 space gap */

	switch (*endptr){
	case 'G': case 'g': size *= 1024; /* fall-through */
	case 'M': case 'm': size *= 1024; /* fall-through */
	case 'K': case 'k': size *= 1024; /* fall-through */
	default:
		break;
	}
	return size;
}

    static uint64_t
get_default_hp_size(void)
{
	const char proc_meminfo[] = "/proc/meminfo";
	const char str_hugepagesz[] = "Hugepagesize:";
	unsigned hugepagesz_len = sizeof(str_hugepagesz) - 1;
	char buffer[256];
	unsigned long long size = 0;

	FILE *fd = fopen(proc_meminfo, "r");
	if (fd == NULL)
		printf("Cannot open %s\n", proc_meminfo);
	while(fgets(buffer, sizeof(buffer), fd)){
		if (strncmp(buffer, str_hugepagesz, hugepagesz_len) == 0){
			size = rte_str_to_size(&buffer[hugepagesz_len]);
			break;
		}
	}
	fclose(fd);
	if (size == 0)
		printf("Cannot get default hugepage size from %s\n", proc_meminfo);
	return size;
}

int main(){
	size_t hsize = get_default_hp_size();
	printf("hsize:%ld\n", hsize);
	return 0;
}