Spliting a string - c

Question

I'm trying to make a program that should split a string in half but so far the program is printing out random letters when I want it to read what the user writes and use the string to split it in half. Another thing is that I'm not sure of is how to write the splitting into two (I have written that part as str/2).
int main() {
int x;
printf("Pick the program that should be executed:\n");
printf(" 1. Split text\n Enter an option:\n");
scanf("%d", &x);
if (x == 1) {
// testing example
printf("Write the text you want to use:\n");
char str[100];
fgets(str, 100, stdin);
printf("Input was: %s\n", str);
char test[] = str;
char *left;
char *right;
// first make a copy
left = strcpy(test);
// second locate the desired text and split in half
right = strstr(left, (str/2));
// third split the string
*(right - 1) = '\0';
// print the results
printf("Original : %s\nLeft side: %s\nRight side: %s\n\n", test, left, right);
// clean up
free(left);
}
return main();
}

Answer 1

This is a possible solution for your problem, and the problem was at Point 1 where either you use case A or case B. The problem here is that you were using both scanf and fgets functions and since scanf doesn't consume the \n and fgets does you would always get an "empty" string (just a \n) in the str variable. So in case A you just use another scanf or in case B you need to consume that last \n and then read the string you want.
Besides that, for the spliting part I'm just using a simple memcpy function and spliting the string in half with the help of strlen to calculate the string's length.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main() {
int x;
printf("Pick the program that should be executed:\n");
printf(" 1. Split text\n Enter an option:\n");
scanf("%d", &x);
if (x == 1) {
printf("Write the text you want to use:\n");
char str[100];
// -- Point 1 --
// A
//scanf("%s", str);
// B
getchar();
fgets(str, 100, stdin);
// -------------
printf("Input was: %s\n", str);
int len = strlen(str);
char *left, *right;
left = malloc(len/2 + 1);
right = malloc(len/2 + 1);
memcpy(left, str, len/2);
left[len/2] = 0;
memcpy(right, str + len/2, len/2);
right[len/2] = 0;
// print the results
printf("Original : %s\nLeft side: %s\nRight side: %s\n\n", str, left, right);
// clean up
free(left);
free(right);
}
return 0;
}