C语言学习

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char *exf_ip = "Let us";
int exf_i = 1;
int exf_i0 = 0;
int exf_ni;
static int exf_si = 2;
static int exf_si0 = 0;
static int exf_sni;
const int exf_c = 10; 
static const int exf_sc = 20; 

int main(int argc, char *argv[])
{
    int inf_i = 3;
    int inf_ni;
    char *inf_ih = malloc(100);
    static char *inf_ip = "learn c language.";
    static int inf_si = 4;
    static int inf_si0 = 0;
    static int inf_sni;

    if (inf_ih) {
        strcpy(inf_ih, exf_ip);
        strcat(inf_ih, " ");
        strcat(inf_ih, inf_ip);
        puts(inf_ih);
        free(inf_ih);
    }   

    exf_ni = 0;
    exf_i++;
    exf_si++;
    exf_si0++;
    exf_sni = 0;

    inf_i++;
    inf_ni = 0; inf_ni++;
    inf_si++;
    inf_si0++;
    inf_sni = 0; inf_sni++;

    return 0;
}