Tiny reverse
#include <stdio.h>
#include <unistd.h>
int main() {
char *b = NULL;
size_t bsize = 0;
for (ssize_t read = getline(&b, &bsize, stdin); read > 0; read = getline(&b, &bsize, stdin))
for (; read >= 0; read--)
write(STDOUT_FILENO, &b[read], 1);
}