How to copy a string to a 2D array in c - arrays

Question

I want to create a c program that when the user enters some words like this: "some,words, in, c, proramming." the program save words in the string "str", then it creates Dynamically a 2D array and copies the words into the 2D array:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <math.h>
#include <conio.h>
void freeMememory(int**array, int row){
for(int i=0;i<row;i++)
free(array[i]);
free(array);
}
int lettersCount(char *arr){
int space=0, letters=0;
do{
if(*arr !=' '&& *arr!='\t' && *arr!=','&& *arr!='.'){
letters =letters+1;
}
++arr;
}while(*arr);
return letters;
}
int wordCount(char *arr){
int space=0, words=0;
for(int i=0; arr[i]!='\0'; i++){
if(arr[i] ==' '|| arr[i]=='\t'|| arr[i]=='\n'||arr[i]==','||arr[i]=='.'){
space++;
}
if(space>0){
words++;
space=0;
}
}
return words;
}
int main (){
char arr[100];
int i, j, row, column;
scanf("%[^\n]s", &arr);
int *words = wordCount(arr);
int *letters = lettersCount(arr);
row=words;
column=letters;
int **ptr = (int **)malloc(row*column*sizeof(int));
for(i=0;i<row;i++){ptr[i]=(int*)malloc(column*sizeof(int));}
/*
//how should I write here to copy only words from arr to ptr?
like this:
arr = "some words, two,three,four."
ptr = {
"some", "words", "two", "", "three", "four",
}
*/
freeMememory(ptr, row);
return 0;}
So any ideas how to copy only the words from the string into the 2D array without copying (periods, spaces, cammas)?

Answer 1

What you might be looking for is strtok from <string.h>. I will also replace row with rows and column with columns in the following code snippet, as suggested by tadman in the comments.
/* no need to cast `malloc` */
char *ptr[rows];
for (int i = 0; i < rows; ++i) {
ptr[i] = malloc(columns);
if (!token) {
fprintf(stderr, "Error: memory allocation failed\n");
exit(EXIT_FAILURE);
}
}
const char *delims = " \t\n,.";
/* second argument are delimiters */
strcpy(ptr[0], strtok(arr, delims));
for (int i = 1; i < rows; ++i)
strcpy(ptr[i], strtok(NULL, delims));
I would also suggest simplifying your functions. For example your wordCount function could probably be simplified to this:
int count_words(char *str, const char *delims)
{
words = 1;
for (int i = 0; str[i] != '\0'; ++i)
if (strchr(delims, str[i]))
++words;
return words;
}
The function count_words could then be called like this:
const char *delims = " \t\n,.";
int words = count_words(arr, delims);

Answer 2

First notice that your code isn't using a 2D array. It's using an array of char-pointers that each point to a char-array. It's a different thing but it can be used in much the same way.
Below is an implementation that uses strtok to split the input string. Further, it uses realloc to make the array of char-pointers grow when a new word is found. Finally it uses a sentinel (i.e. NULL) to indicate end-of-words.
The code is pretty simple but the performance is poor.
Example:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
char** split(const char* str)
{
if (str == NULL) exit(1);
// Copy input string as strtok changes its input
char* str_cpy = malloc(strlen(str) + 1);
if (str_cpy == NULL) exit(1);
strcpy(str_cpy, str);
unsigned num_rows = 0;
char** arr = NULL;
// Get first token
const char *delims = " \t\n,.";
char* ptr = strtok(str_cpy, delims);
while (ptr)
{
// Allocate one more row
arr = realloc(arr, (num_rows + 1) * sizeof *arr);
if (arr == NULL) exit(1);
// Allocate memory for one more word
arr[num_rows] = malloc(strlen(ptr) + 1);
if (arr[num_rows] == NULL) exit(1);
strcpy(arr[num_rows], ptr);
++num_rows;
// Get next token
ptr = strtok(NULL, delims);
}
// Add a sentinel to indicate end-of-words
arr = realloc(arr, (num_rows + 1) * sizeof *arr);
if (arr == NULL) exit(1);
arr[num_rows] = NULL;
free(str_cpy);
return arr;
}
int main(void)
{
char* str = "some,words, in, c, programming.";
char** arr = split(str);
printf("Original string: %s\n", str);
for (int i=0; arr[i] != NULL; ++i)
{
printf("Word[%d]: %s\n", i, arr[i]);
}
// Free array
for (int i=0; arr[i] != NULL; ++i)
{
free(arr[i]);
}
free(arr);
return 0;
}
Output:
Original string: some,words, in, c, programming.
Word[0]: some
Word[1]: words
Word[2]: in
Word[3]: c
Word[4]: programming