recursive-count.c

#include <stdio.h>

void countNewLine(char, int *);

int main(void)
{
    int count = 0;

    countNewLine(getchar(), &count);

    printf("Your input has %d newline%c\n", count, (count > 1) ? 's' : ' ');
    
    return 1;
}

void countNewLine(char c, int *count)
{
    if (c == EOF)
        return;

    if (c == '\n')
        ++(*count);

    countNewLine(getchar(), count);
}