Delete from file string with digit

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <ctype.h>
#define N 1024

int check_str(uint8_t *str){
    for (int i=0; i<strlen((char*)str); i++){
        if (isdigit(str[i])>0){
            return 1;
        }
    }
    return 0;
}

int main (int argc, char **argv)
{
    if (argc < 3) {
        printf("Wrong count of params. Usage ./command [file_src_name] [file_dest_name]\n");
        exit(1);
    }

    FILE *fp, *fp2;
    if ((fp = fopen (argv[1], "r")) == NULL)
    {
        printf ("Error open file.\n");
        exit (1);
    }

    if ((fp2 = fopen (argv[2], "w")) == NULL)
    {
        printf ("Error open file.\n");
        exit (1);
    }

    uint8_t buffer[N];
    while(!feof(fp)) {
        memset(buffer, '\0',N);
        if(fgets((char*)buffer, N, fp))
        {
            if (0 == check_str(buffer))
            {
                fputs((char*)buffer, fp2);
                printf("%s", buffer);
            }
        }
    }
    fclose (fp2);
    fclose (fp);
    return 0;
}