Scan chars from user linked list of

Question

I'm supposed to write a function that scan input from user till enter and enter it to linked list. I cant scan it into a String and than put it in a list.

I wrote this code and doesn't enter the chars to linked list and doesn't exit from the console till I press Exit.

typedef struct chNode
{
    char data;
    struct chNode *next;
}chNode;


chNode * createCharList(char data)
{
    chNode *temp = (chNode*)malloc(sizeof(chNode));
    temp->data = data;
    temp->next = NULL;
    return temp;
}

chNode * addCharToLast(chNode *head, char data)
{
    chNode *p = head;
    chNode *temp = createCharList(data);
    if (head == NULL)
        return temp;
    while (p->next != NULL)
        p = p->next;
    p->next = temp;
    return head;
}


chNode* insert_Charlist() 
{
    char ch;
    chNode *Head = NULL;
    printf("Enter chars For Linked-List Till 'Enter':\n");
    scanf_s("%c", &ch);
    while (ch != '\n')
    {

        Head = addCharToLast(Head, ch); 
        scanf_s("%c", &ch);
        
    }
    return Head;
}

void main()
{

    chNode *Orignial_list = NULL;
    Orignial_list = insert_Charlist(); // Function that imports a list
    printf("You Entered This linked-list:\n");
    printf_CharList(Orignial_list); //Printing the linked list
    
    getch();

}

Answer 1

For this call of scanf

scanf_s("%c", &ch);

you need to specify one more argument

scanf_s( "%c", &ch, 1 );

Your approach of the implementation of the function insert_Charlist with calls of the function addCharToLast is inefficient because the function addCharToLast will traverse the whole list each time when a new character is added to the list.

I can suggest the following function implementation as it is shown in the demonstrative program below.

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

typedef struct chNode
{
    char data;
    struct chNode *next;
} chNode;

chNode * createNode(char data )
{
    chNode *temp = (chNode*)malloc( sizeof( chNode ) );
    
    if ( temp != NULL )
    {
        temp->data = data;
        temp->next = NULL;
    }
    
    return temp;
}

size_t insert_Charlist( chNode **head ) 
{
    while ( *head ) head = &( *head )->next;
    
    size_t n = 0;
    
    printf( "Enter chars For Linked-List Till 'Enter': " );

    for ( int data; ( data = getchar() ) != EOF && 
                    data != '\n' && 
                    ( *head = createNode( data ) ) != NULL; )
    {
        head = &( *head )->next;
        ++n;
    }
    
    return n;
}

void printf_CharList( const chNode *head )
{
    for ( ; head != NULL; head = head->next )
    {
        printf( "%c -> ", head->data );
    }
    
    puts( "null" );
}

int main(void) 
{
    chNode *head = NULL;
    
    insert_Charlist( &head );
    
    printf_CharList( head );
    
    return 0;
}

The program output might look like

Enter chars For Linked-List Till 'Enter': Hello
H -> e -> l -> l -> o -> null

Pay attention to that according to the C Standard the function main without parameters shall be declared like

int main( void )