I’m just looking for some feed back on the following functions. Pretty straight forward and simple, but if additional information is desired, ask and I will gladly oblige. Comments, suggestions, etc are welcomed.

// remove duplicate characters in array word and return the resulting string  char * removeDuplicates(char * word){   char * result;   int len = strlen(word) + 1;   result = malloc (len);    if (result == NULL){     errorHandler(2);   }    for(int i = 0, j = 0; i < len; i++){     char ch;     ch = word[i];      if(!targetFound(result, i, ch)){       result[j] = ch;       j++;     }     result[j] = '';   }    return result; }  // search the characters in array charArray for character target // return a non-zero integer if found, otherwise, return 0 int targetFound(char * charArray, char target){   int found = 0;    if(strchr(charArray,target))     found = 1;    return found; }  // initialize the encrypt array with appropriate cipher letters according to the given key void initializeEncryptArray(char * key, char * encrypt){   char ch;    for (int i = 0, j = 0, flag = 0; j < 26;){     ch = key[i];      if (ch == '' || flag == 1){       if(flag == 0)         flag = 1;        ch = 'Z' - j;       j++;     }      if (strchr(encrypt,ch) == NULL){       encrypt[i] = toupper(ch);       i++;     }   } }  // initialize the decrypt array with appropriate cipher letters according to the given key void initializeDecryptArray(char * encrypt, char * decrypt){   int i;   for ( i = 0; i < 26; i++){     decrypt[encrypt[i] - 'A'] = i + 'A';   } }  // process data from the input file and write the result to the output file // pass the encrypt array to parameter substitute if encryption is intended // pass the decrypt array to parameter substitute if decryption is intended void processInput(char * substitute, FILE * fin, FILE * fout){   char ch;   while ( fscanf(fin, "%c", &ch) != EOF ){     if(isupper(ch)){       fprintf(fout, "%c", substitute[ch - 'A']);     }     else if(islower(ch)){       fprintf(fout, "%c", tolower(substitute[ch - 'a']));     }     else       fprintf(fout, "%c", ch);     } }