如何为我的char指针分配内存？

Question

My assignment is to allow the user to enter any input and print the occurrences of letters and words, we also have to print out how many one letter, two, three, etc.. letter words are in the string. I have gotten the letter part of my code to work and have revised my word function several times, but still can't get the word finding function to even begin to work. The compiler says the char pointer word is undeclared when it clearly is. Do I have to allocate memory to it and the array of characters?

#include <stdio.h>
#include <stdlib.h>
#include <string.h>


void findLetters(char *ptr);
void findWords(char *point);


int main()
{
    char textStream[100]; //up to 98 characters and '\n\ and '\0'

    printf("enter some text\n");
    if (fgets(textStream, sizeof (textStream), stdin)) //input up to 99 characters
    {
        findLetters(textStream);
        findWords(textStream);
    }
    else
    {
        printf("fgets failed\n");
    }

    return 0;
}

void findLetters(char *ptr) //find occurences of all letters
{
    int upLetters[26];
    int loLetters[26];
    int i;
    int index;

    for (i = 0; i < 26; i++) // set array to all zero
    {
        upLetters[i] = 0;
        loLetters[i] = 0;
    }
    i = 0;
    while (ptr[i] != '\0') // loop until prt[i] is '\0'
    {
        if (ptr[i] >= 'A' && ptr[i] <= 'Z') //stores occurrences of uppercase letters
        {
            index = ptr[i] - 'A';// subtract 'A' to get index 0-25
            upLetters[index]++;//add one
        }

        if (ptr[i] >= 'a' && ptr[i] <= 'z') //stores occurrences of lowercase letters
        {
            index = ptr[i] - 'a';//subtract 'a' to get index 0-25
            loLetters[index]++;//add one
        }
        i++;//next character in ptr
    }
    printf("Number of Occurrences of Uppercase letters\n\n");
    for (i = 0; i < 26; i++)//loop through 0 to 25
    {
        if (upLetters[i] > 0)
        {
            printf("%c : \t%d\n", (char)(i + 'A'), upLetters[i]);
            // add 'A' to go from an index back to a character
        }
    }
    printf("\n");
    printf("Number of Occurrences of Lowercase letters\n\n");
    for (i = 0; i < 26; i++)
    {
        if (loLetters[i] > 0)
        {
            printf("%c : \t%d\n", (char)(i + 'a'), loLetters[i]);
            // add 'a' to go back from an index to a character
        }
    }
    printf("\n");
}

void findWords(char *point)
{
    int i = 0;
    int k = 0;
    int count = 0;
    int j = 0;
    int space = 0;
    int c = 0;
    char *word[50];
    char word1[50][100];
    char* delim = "{ } . , ( ) ";

    for (i = 0; i< sizeof(point); i++) //counts # of spaces between words
    {
        if ((point[i] == ' ') || (point[i] == ',') || (point[i] == '.'))
        {
            space++;
        }
    }
    char *words = strtok(point, delim);
    for(;k <= space; k++)
    {
        word[k] = malloc((words+1) * sizeof(*words));
    }

        while (words != NULL)
        {
            printf("%s\n",words);
            strcpy(words, word[j++]);
            words = strtok(NULL, delim);
        }

    free(words);
}

Answer 1

This is because you are trying to multiply the pointer position+1 by the size of pointer. Change line 100 to:

    word[k] = malloc(strlen(words)+1);

This will solve your compilation problem, but you still have other problems.

Answer 2

Your calculation of the pointer position+1 is wrong. If you want the compilation problem will go away change line 100 to:

word[k] = malloc( 1 + strlen(words));

Answer 3

You've got a couple of problems in function findWords :

1. Here,

    for (i = 0; i< sizeof(point); i++) 

   sizeof(point) is the same as sizeof(char*) as point in a char* in the function fincdWords . This is not what you want. Use

    for (i = 0; i < strlen(point); i++) 

   instead. But this might be slow as strlen will be called in every iteration. So I suggest

    int len = strlen(point); for (i = 0; i < len; i++) 

2. The same problem lies here too:

    word[k] = malloc((words+1) * sizeof(*words)); 

   It doesn't makes sense what you are trying with (words+1) . I think you want

    word[k] = malloc( strlen(words) + 1 ); //+1 for the NUL-terminator 

3. You got the arguments all mixed up:

    strcpy(words, word[j++]); 

   You actually wanted

    strcpy(word[j++], words); 

   which copies the contents of words to word[j++] .

4. Here:

    free(words); 

   words was never allocated memory. Since you free a pointer that has not been returned by malloc / calloc / realloc , the code exhibits Undefined Behavior. So, remove that. You allocated memory for each element of word . So free it using

    for(k = 0; k <= space; k++) { free(word[k]); }