How to Assign Random String to 2D Array - c

Question

The program reads a file which includes one word in every line.After reading random word put random word in a pointer and return the pointer .in main function
printf("%s",func("example.txt",str)) it prints different string when the program run.I want to do this in 2d array(20*20) like table,but i could not imagine how to do this.When i print the the function in internal loop,it give me the same word in every loop step.
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
char *word(char *file, char *str);
int main() {
char *str ;
int i, j;
str = (char *)malloc(20);
srand(time(NULL));
char *puzzle[20][20];
for (i = 0; i < 20; i++) {
for (j = 0; j < 20; j++) {
puzzle[i][j] = word("words.txt", str);
}
}
for (i = 0; i < 20; i++) {
for (j = 0; j < 20; j++) {
printf("%s ", puzzle[i][j]);
}
printf("\n");
}
}
char *word(char *file, char *str) {
int end, loop, line;
FILE *fd = fopen(file, "r");
if (fd == NULL) {
printf("Failed to open file\n");
return (NULL);
}
srand(time(NULL));
line = rand() % 100 + 1;
for (end = loop = 0; loop < line; ++loop) {
if (0 == fgets(str, 20, fd)) {
end = 1;
break;
}
}
if (!end)
return (char *)str;
fclose(fd);
free(str);
}

Answer 1

I do not have your words.txt file, so I've created some random strings below.
And a note:
Because your nested loop is in the main, your code opens the file in the sub function and returns w/o closing it; then returns to the sub and reopens, and again, and again... It's always better to read at once and close the file before returning from the sub.
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
char **word(int countString, int maxChars) {
int i;
int j;
int k;
// allocate memory for pointers that are pointing to each string
char **arrStr = malloc(countString * sizeof(char *));
// srand(time(NULL));
for (i = 0; i < countString; i++) {
// create a random string with a length of 'k'
// say, 5 <= k <= maxChars
// that (+ 1) is for the string terminating character '\0'
k = (rand() % (maxChars - 5)) + 5 + 1;
// allocate memory for string
arrStr[i] = malloc(k * sizeof(char));
for (j = 0; j < k - 1; j++) {
*(arrStr[i] + j) = rand() % 26 + 'A';
}
*(arrStr[i] + j) = '\0';
}
return arrStr;
}
int main() {
int countString = 10;
int maxChars = 20;
char **arrStr = NULL;
int i;
arrStr = word(countString, maxChars);
for (i = 0; i < 10; i++) {
printf("%s\n", *(arrStr + i));
}
// do not forget to free the strings
// and then the string pointers (array)
return 0;
}