Reading integers

john.c

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

int main(int argc, char *argv[])
{
    char pattern[] = "/tmp/*.txt";
    glob_t globbuf;
    FILE *file;
    int i, num, n = 0, max = 10;
    int *numbers = malloc(sizeof(int) * max);

    glob(pattern, 0, NULL, &globbuf);
    char buf[80];
    for (i = 0; i < globbuf.gl_pathc; i++)
    {
        if ((file = fopen(globbuf.gl_pathv[i], "r")) != NULL)
        {
            while (fscanf(file, "%s\n", buf) == 1)
            {
                char *p = buf;
                errno = 0;
                num = (int) strtoul(buf, &p, 10);
                if((errno != 0) || (p == buf) || (*p != 0)) {
                    continue;
                }

                numbers[n] = num;
                n++;

                if (n >= max)
                {
                    max = max * 2;
                    numbers = realloc(numbers, sizeof(int) * max);
                }
            }
            fclose(file);
        }
    }

    globfree(&globbuf);

    printf("Collected numbers:\n");

    for (i = 0; i < n; i++)
    {
        printf("%d\n", numbers[i]);
    }

    free(numbers);

    return 0;
}