charとint

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

int main(int argc, char* argv[])
{
    FILE *fp;
    char c[5] = { '1', '2', '3', '4', '5' };

    if ( (fp = fopen("/tmp/foo", "w")) == NULL ) {
        exit(EXIT_FAILURE);
    }

    fwrite(c, sizeof(char), 5, fp);
    fclose(fp);

    exit(EXIT_SUCCESS);
}

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

int main(int argc, char* argv[])
{
    FILE *fp;
    int  i[5] = {   1,  2 ,  3 ,  4 ,  5  };

    if ( (fp = fopen("/tmp/foo", "w")) == NULL ) {
        exit(EXIT_FAILURE);
    }

    fwrite(i, sizeof(int), 5, fp);
    fclose(fp);

    exit(EXIT_SUCCESS);
}

ふむ。