Count alphabetic characters from standard input.

count-alpha-chars-in-stdin.c

#include <stdio.h>

int main()
{
  int frequency[26];
  int ch;

  for (ch = 0; ch < 26; ch++)
    frequency[ch] = 0;
   
  while (1)
  {
    ch = fgetc(stdin);
    if (ch == EOF) break;
   
    if ('a' <= ch && ch <= 'z')      // lower case
      frequency[ch-'a']++;
    else if ('A' <= ch && ch <= 'Z') // upper case
      frequency[ch-'A']++;
  }
  
  for(ch = 0; ch < 26; ch++)
  {
    //if(frequency[ch] > 0)
    //  printf("%c: %d\n", 'A' + ch, frequency[ch]);
    printf("%d\n", frequency[ch]);
  }
  return 0;
}