Structure-based file-like record handling (in memory) Dry Run in C

Structure-based file-like record handling (in memory) is an interactive C dry run visualizer from the Struct Functions Pointers programs section. Study the source code, then use the execution controls to follow each step, variable update, highlighted line, and console output.

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Structure-based file-like record handling (in memory) Program Code

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

struct Record {
    int id;
    char data[100];
    struct Record *next;
};

// File-like operations in memory
struct Record* createRecord(int id, char data[]) {
    struct Record *newRec = (struct Record*)malloc(sizeof(struct Record));
    newRec->id = id;
    strcpy(newRec->data, data);
    newRec->next = NULL;
    return newRec;
}

void insertRecord(struct Record **head, struct Record *rec) {
    rec->next = *head;
    *head = rec;
}

struct Record* searchRecord(struct Record *head, int id) {
    struct Record *current = head;
    while(current != NULL) {
        if(current->id == id)
            return current;
        current = current->next;
    }
    return NULL;
}

int deleteRecord(struct Record **head, int id) {
    struct Record *current = *head;
    struct Record *prev = NULL;
    
    while(current != NULL) {
        if(current->id == id) {
            if(prev == NULL) {
                *head = current->next;
            } else {
                prev->next = current->next;
            }
            free(current);
            return 1;
        }
        prev = current;
        current = current->next;
    }
    return 0;
}

void updateRecord(struct Record *head, int id, char newData[]) {
    struct Record *rec = searchRecord(head, id);
    if(rec != NULL) {
        strcpy(rec->data, newData);
        printf("Record %d updated\n", id);
    } else {
        printf("Record %d not found\n", id);
    }
}

void displayAll(struct Record *head) {
    struct Record *current = head;
    printf("\n--- All Records ---\n");
    while(current != NULL) {
        printf("ID: %d -> %s\n", current->id, current->data);
        current = current->next;
    }
}

void freeAll(struct Record *head) {
    struct Record *current = head;
    while(current != NULL) {
        struct Record *temp = current;
        current = current->next;
        free(temp);
    }
}

int main() {
    struct Record *database = NULL;
    
    // Simulate file operations
    insertRecord(&database, createRecord(1, "First record - User data"));
    insertRecord(&database, createRecord(2, "Second record - Configuration"));
    insertRecord(&database, createRecord(3, "Third record - Log entry"));
    
    displayAll(database);
    
    struct Record *found = searchRecord(database, 2);
    if(found) printf("\nFound: ID %d -> %s\n", found->id, found->data);
    
    updateRecord(database, 2, "Updated second record - New data");
    
    displayAll(database);
    
    deleteRecord(&database, 1);
    printf("\nAfter deleting ID 1:\n");
    displayAll(database);
    
    freeAll(database);
    
    return 0;
}

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