Scan dictionary for words that have letters adding up to 100

letterati.c

#define _GNU_SOURCE // F U RMS... won't compile without this!
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* Inspired by a silly meme that tries to connect the alphabet and corresponding
 * letters with numbers (A=1, B=2, ... Z=26) such that "HARDWORK" and "KNOWLEDGE"
 * are insufficient, and only "ATTITUDE" = 100%.
 */

int sum(char*);

int main()
{
  char* word = (char *)malloc(sizeof(char) * 255); // 255 is plenty for dictionary words
  size_t len = 0;                                  // not actually used
  ssize_t read;
  FILE* fp = fopen("/usr/share/dict/words", "r");

  if(fp == NULL)
    exit(EXIT_FAILURE);

  while((read = getline(&word, &len, fp)) != -1)
    if(sum(word) == 100)
      printf("%s", word);
}

/*
 * return the sum of the letters
 */
int sum(char* str)
{
  int ret = 0;

  for(int i = 0; i <=strlen(str); i++ )
  {
    if(str[i] >=65 && str[i] <= 90)
      ret += (str[i] - 64);
    else if(str[i] >= 97 && str[i] <= 122)
      ret += (str[i] - 96);
  }

  return ret;
}