How to Identify if an input string is an int, float or char in C

Question

I'm working on a code where I use linked list to accept a string data and put it into a main list and specific list where the data belongs. I'm having trouble on how do I do it as I've tried but output is different of what is expected. There are no errors, however. If anyone would try to look and help me I would gladly apprectiate it. Thank you....

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

struct data
{
    char info[10];
    struct data *prev;
    struct data *next;
};

typedef struct data* nodePtr;

nodePtr CreateData(char info[])
{
    nodePtr newData = (nodePtr)malloc(sizeof(struct data));
    strcpy(newData->info, info);
    newData->next = newData->prev = NULL;
    return newData;
}

void AddData(nodePtr *head, nodePtr *tail, nodePtr *headInt, nodePtr *tailInt, nodePtr *headFloat, nodePtr *tailFloat, nodePtr *headChar, nodePtr *tailChar, char info[])
{
    int flag = 0;
    int loopVar;
    nodePtr newData = CreateData(info);
    
    if(*head == NULL)
    {
        *head = *tail = newData;
        (*head)->prev = NULL;
        (*tail)->next = NULL;
    }
    
    else
    {
        (*tail)->next = newData;
        newData->prev = *tail;
        *tail = newData;
        (*tail)->next = NULL;
    }
    
    loopVar = 0;
    while(info[loopVar++] != '\0')
    {
        if(info[loopVar] == '.')
        {
            flag = 1;
            break;
        }
    }
    
    if(flag == 1 && atof(info) != 0)
    {
        if(*headFloat == NULL)
        {
            *headFloat = *tailFloat = newData;
            (*headFloat)->prev = NULL;
            (*tailFloat)->next = NULL;
        }
    
        else
        {
            (*tailFloat)->next = newData;
            newData->prev = *tailFloat;
            *tailFloat = newData;
            (*tailFloat)->next = NULL;
        }
    }
    
    else if(flag == 0 && atoi(info) != 0)
    {
        if(*headInt == NULL)
        {
            *headInt = *tailInt = newData;
            (*headInt)->prev = NULL;
            (*tailInt)->next = NULL;
        }
    
        else
        {
            (*tailInt)->next = newData;
            newData->prev = *tailInt;
            *tailInt = newData;
            (*tailInt)->next = NULL;
        }
    }
    
    else if(atoi(info) == 0 && atof(info))
    {
        if(*headChar == NULL)
        {
            *headChar = *tailChar = newData;
            (*headChar)->prev = NULL;
            (*tailChar)->next = NULL;
        }
    
        else
        {
            (*tailChar)->next = newData;
            newData->prev = *tailChar;
            *tailChar = newData;
            (*tailChar)->next = NULL;
        }
    }
} 

void DisplayData(nodePtr head)
{
    nodePtr current = head;
    
    while(current != NULL)
    {
        printf("%s ", current->info);
        current = current->next;
    }
    
    printf("\n");
}

void main()
{
    nodePtr head = NULL;
    nodePtr tail = NULL;
    nodePtr tailInt = NULL;
    nodePtr headInt = NULL;
    nodePtr tailFloat = NULL;
    nodePtr headFloat = NULL;
    nodePtr tailChar = NULL;
    nodePtr headChar = NULL;
    AddData(&head, &tail, &headInt, &tailInt, &headFloat, &tailFloat, &headChar, &tailChar, "1.2");
    AddData(&head, &tail, &headInt, &tailInt, &headFloat, &tailFloat, &headChar, &tailChar, "1.1");
    AddData(&head, &tail, &headInt, &tailInt, &headFloat, &tailFloat, &headChar, &tailChar, "123");
    AddData(&head, &tail, &headInt, &tailInt, &headFloat, &tailFloat, &headChar, &tailChar, "2");   
    AddData(&head, &tail, &headInt, &tailInt, &headFloat, &tailFloat, &headChar, &tailChar, "A");
    DisplayData(head);
    DisplayData(headFloat);
    DisplayData(headInt);
    DisplayData(headChar);
}

Answer 1

You said:

but output is different of what is expected

Well, I am not sure what the "expected" here is exactly defined, but you code seems to try to insert different types of string into different list and display them. I notice you also display the main list(i.e. DisplayData(head)). If you want each node to appear on two lists: the main list and its type list, you need at least two pairs of pointer. For example:

struct data
{
    char info[10];
    struct data *prev;
    struct data *next;
    struct data *main_prev;
    struct data *main_next;
};

The extra main_* pointer pair will serve to make each node appear on the main list.