File testing

#include <stdio.h> //for input, output, files
#include <string.h> //for string functions

char text[1000]; //text string of size 1000
char words[100][20]; //string array for 100 strings with max of 20-1=19 size
int words_freq[100]; //array for max of 100 word frequency's (they can be less)
int letters_freq[26]; //array with the frequency's of the letters of the alphabet in the text

int word_count = 0; //word counter
char *p; //pointer for char functions

void read_text_from_file(); //function to read the text from the file
void letter_frequency(); //find letter frequencies
void separate_words(); //find the words from the text, without repeat and with frequency's
void sort_words(); //sorts the words array alphabetically
void print_words_to_file(); //print words to file with first and last letter being caps

int main(){
    int i;
    int count;
    char letter; //letter to search for

    read_text_from_file();
    printf("Text:\n%s", text); //print text
    letter_frequency();

    separate_words();
    sort_words();
    //print words
    printf("\nWords:\n");
    for(i = 0; i < word_count; i++){
        printf("words[%d] = %s (freq = %d)\n", i, words[i], words_freq[i]);
    }
    print_words_to_file();

    printf("\nSearch for words starting with: ");
    scanf("%c", &letter);
    fflush(stdin);
    if(letter <= 'Z'){ //if they give big one
        letter = letter + 32;
    }
    count = 0;
    for(i = 0; i < word_count; i++){ //search all words
        if( words[i][0] == letter ){ //check first letter
            printf("%s starts with %c\n", words[i], letter);
            count++;
        }
    }
    if(count == 0){ //if nothing found
        printf("No word starts with %c!\n", letter);
    }else{
        printf("%d words start with %c!\n", count, letter);
    }

    printf("\nSearch for words ending with: ");
    scanf("%c", &letter);
    fflush(stdin);
    if(letter <= 'Z'){ //if they give big one
        letter = letter + 32;
    }
    count = 0;
    for(i = 0; i < word_count; i++){ //search all words
        if( words[i][strlen(words[i])-1] == letter ){ //check last letter
            printf("%s starts with %c\n", words[i], letter);
            count++;
        }
    }
    if(count == 0){ //if nothing found
        printf("No word ends with %c!\n", letter);
    }else{
        printf("%d words end with %c!\n", count, letter);
    }




}

void read_text_from_file(){
    char buf[80]; //buffer for reading line by line
    FILE *fp; //file pointer

    fp = fopen("text.txt", "r"); //open the text for reading
    if(fp == NULL){ //error checking
        printf("File not found!\n");
    }

    fgets(buf, 80, fp); //read from the file
    strcpy(text, buf); //set the text to the first buffer
    while( fgets(buf, 100, fp) != NULL){ //read until end of file
        strcat(text, buf); //add buffer at the end of the string, concatenating them
    }
    fclose(fp); //close the file
}

void letter_frequency(){
    int i, j;
    char letter = 'a';

    for(i = 0; i < 26; i++){ //for every letter in the alphabet
        letters_freq[i] = 0;
        for(j = 0; j < strlen(text); j++){
            if(text[j] == letter || text[j] == letter - 32){ //if it is the small or cap letter
                letters_freq[i]++;
            }
        }
        letter++; //go to next letter
    }
    letter = 'a';
    printf("\nFrequency of Letters:\n");
    for(i = 0; i < 26; i++){
        printf("%c: %d\n", letter, letters_freq[i]);
        letter++;
    }
}

void separate_words(){
    int i;
    int number, min_length, same; //flags for words

    p = strtok(text," \"\n\t\r,.-;!"); //p will point at the next address that is not one of the tokens (second parameter)
    while (p != NULL){ //while not at the end of the text
        number = 0; //no number in "word"
        min_length = 1; //length must be at least 2 to be a word

        if(strlen(p) > 1); //if enough do nothing
        else min_length = 0; //too small length

        for(i = 0; i < strlen(p); i++){ //search whole "word" for numbers
            if(p[i] >= '0' && p[i] <= '9'){ //numbers are in character form and because of ASCII one after another
                number = 1; //there is a number inside
            }
        }

        //make all capital letters small letters
        if( p[0] <= 'Z'){ //in ASCII all characters are in alphabetic order
                p[0] = p[0] + 32; //small ones are 32 "higher" then capital ones
        }

        if(number == 0 && min_length == 1){  //if it is doesn't have numbers and is at least of length two
            same = 0; //words is not inserted yet
            //search for the word in all the inserted words
            for(i = 0; i <word_count; i++){
                if( strcmp(p, words[i]) == 0 ){ //if p and words[i] are equal it will return 0
                    same = 1; //word already inserted
                    words_freq[i]++; //increment the frequency of the word
                    break; //break the for loop, cause you can't find it another time
                }
            }
            if(same == 0){ //if it was not inserted
                strcpy(words[word_count], p); //insert word into array
                words_freq[word_count] = 1; //set frequency to 1
                word_count++; //update word counter
            }
        }
        p = strtok(NULL," \"\n\t\r,.-;!"); //continue from where you stopped at the text searching for words

    }
}

void sort_words(){
    int i, j;
    char word[20]; //temporary word for swapping

    for(i = 0; i < word_count; i++){
        for(j = i; j < word_count; j++){
            if( strcmp(words[i], words[j]) > 0 ){ //when it returns > 0 it means first one is higher alphabetically
                //swap using temporary variable
                strcpy(word, words[i]);
                strcpy(words[i], words[j]);
                strcpy(words[j], word);
            }
        }
    }
}

void print_words_to_file(){
    FILE *fp; //file pointer
    int i;
    char word[20]; //temporary word for editing

    fp = fopen("words.txt", "w"); //open file for writing

    for(i = 0; i < word_count; i++){
        strcpy(word, words[i]);
        if(words[i][0] >= 'a') word[0] = word[0] - 32; //if first letter small then make it cap with -32
        if(words[i][ strlen(words[i])-1 ] >= 'a') word[strlen(words[i])-1] = word[strlen(words[i])-1] - 32; //if last one is small do the same
        fprintf(fp, "%s\n", word); //write word to file
    }

    fclose(fp); //close file
}