read a line in C

main.c

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

int fgetline(FILE *fp, char s[], int lim)
{
    char *t;
    int c, len=lim;

    t = s;
    while (--lim>1 && (c=getc(fp)) != EOF && c != '\n')
    {
        *s++ = c;
        if (c == '\n')
            *s++ = c;
        else if (lim == 1)
        {
            *s++ = '\n';
            fprintf(stderr, "WARNING. fgetline: Line too long, splitted.\n");
        }
    }
    *s = '\0';
    return s - t;
}

main()
{
   FILE *fp;
   char buff[255];

   fp = fopen("input.txt", "r");
   fgetline(fp, buff, 20);
   printf("%s\r\n", buff);
}