Below is the pig latin example from today, fixed so that it works! The bugfix is noted in the code below. However, how could you update this code to avoid a stack buffer overflow?

pig.c

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

// read input
// pig latinify
// - find a vowel
// - reorder and ayify
// write it out

const char *findVowel(const char *word) {
  const char *s = strpbrk(word, "aeiouAEIOU");

  // Avoid returning NULL from strpbrk if no
  // vowel was in the word.
  if (s != NULL) 
    return s;
  return word;
}

void showPig(const char *word) {
  const char *vowel = findVowel(word);

  printf("%s", vowel); // print the "ig"
  fwrite(word, sizeof(char), vowel - word, stdout); // print the "p"
  printf("ay"); // print ay
}

int main (int argc, const char *argv[]) {
  // Stack buffer overflow possibility here!
  // We should be VERY CAREFUL and fix this!
  char buffer[4096]; 

  int index = 0;

  // BUGFIX: In class, we were always reading into
  // the first position in the array.  The post-class
  // bug fix was to update the position into the
  // buffer that the next character should be read.
  // read(0, buffer, 1) --> read(0, &buffer[index], 1)
  while(read(0, &buffer[index], 1)) {
    if(isalpha(buffer[index])) {
      index++; // If letter, collect the word in buffer
    } else {
      // If not a letter, handle the prior word
      char saveme = buffer[index];
      if (index > 0) {
        buffer[index] = '\0';
        showPig(buffer);
      }
      // Write the non-letter out
      fwrite(&saveme, sizeof(char), 1, stdout);
      // Reset the buffer
      index = 0;
    }
  } 
  
  return 0;
}