Learning C: Building an Inventory Management System 🚀

Hello, world! 🌍

As a student diving into the world of programming with C, I recently challenged myself with an exciting project: creating an Inventory Management System! 🛠️ This program is a practical way to manage products, categories, quantities, and prices, all while learning key programming concepts.

Let me walk you through what I built, and maybe it will inspire you to try something similar! 🤓

Features of My Inventory Management System 🗂️

1. Add Products 🛒

You can add items to your inventory by specifying their category, name, quantity, and price. These details are stored in a file named Inventory.txt. Here's how the data is saved:

//Category: INFORMATICS
Product: Mouse  Quantity: 20    Price: 15.99€

2. View Inventory 📜

Want to see what you have in stock? The program can display the entire inventory in a neat format. No need to manually search through files—just run the program and select the View Inventory option!

3. Modify Quantities ✏️

If stock levels change, you can update the quantity of any product. This feature reads the file, modifies the necessary line, and saves the updates seamlessly.

4. Split by Category 🗃️

Organize your inventory further by splitting items into separate files based on their categories. For instance, all INFORMATICS products go into Informatics.txt, and ELECTRONICS items go into Electronics.txt.

The Code 🖥️

Here's a snippet of the core functionality:

// Function to add an item to the inventory
void addItem(char category[], char name[], int quantity, float price) {
    FILE *pFile;
    pFile = fopen("Inventory.txt", "a");
    fprintf(pFile, "//Category: %s\nProduct: %s\tQuantity: %d\tPrice: %.2f€\n", category, name, quantity, price);
    fclose(pFile);
}

I implemented several functions to handle specific tasks, like adding items, viewing the inventory, and even splitting it by category. These functions helped me learn how to work with file I/O, string manipulation, and conditional logic in C.

Lessons Learned 📚

File Handling: Managing inventory required reading, writing, and modifying files. This was a fantastic introduction to file handling in C!
String Operations: I practiced working with strings to format data and convert categories to uppercase.
Problem-Solving: Debugging and refining my code taught me to think like a programmer.

Try It Out! 💻

Here’s the full code if you want to experiment:

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

// Function to add an item to the inventory
void addItem(char category[], char name[], int quantity, float price) {
    FILE *pFile;
    // Open file in append mode to add data
    pFile = fopen("Inventory.txt", "a");
    // Write the item details in the file
    fprintf(pFile, "//Category: %s\nProduct: %s\tQuantity: %d\tPrice: %.2f€\n", category, name, quantity, price);
    fclose(pFile); // Close the file
}

// Function to display the inventory
void viewInventory() {
    char line[200];
    FILE *pFile;
    // Open the inventory file in read mode
    pFile = fopen("Inventory.txt", "r");

    // Read and print each line until EOF
    while (fgets(line, sizeof(line), pFile)) {
        printf("%s", line);
    }
    fclose(pFile); // Close the file
}

// Function to modify the quantity of an item
void modifyQuantity(char name[], int newQuantity) {
    char line[200], updatedLine[200], itemName[30];
    int itemQuantity;
    float itemPrice;
    FILE *pFile, *pTmp;

    // Open the original file in read mode and a temporary file in write mode
    pFile = fopen("Inventory.txt", "r");
    pTmp = fopen("Temporary.txt", "w");

    // Read each line and process
    while (fgets(line, sizeof(line), pFile)) {
        sscanf(line, "Product: %s\tQuantity: %d\tPrice:%f€", itemName, &itemQuantity, &itemPrice);

        // If the product matches, update its quantity
        if (strcmp(name, itemName) == 0) {
            sprintf(updatedLine, "Product: %s\tQuantity: %d\tPrice: %.2f€\n", itemName, newQuantity, itemPrice);
            fputs(updatedLine, pTmp);
        } else {
            // Otherwise, copy the original line
            fputs(line, pTmp);
        }
    }
    fclose(pFile);
    fclose(pTmp);

    // Replace the original file with the updated file
    remove("Inventory.txt");
    rename("Temporary.txt", "Inventory.txt");
}

// Function to split inventory items into separate files by category
void splitByCategory() {
    char line[200], categoryName[30], name[30];
    int quantity;
    float price;
    FILE *pFile, *pInf, *pElec;

    // Open the inventory file and category files
    pFile = fopen("Inventory.txt", "r");
    pInf = fopen("Informatics.txt", "w");
    pElec = fopen("Electronics.txt", "w");

    // Process each line
    while (fgets(line, sizeof(line), pFile)) {
        sscanf(line, "//Category: %s\nProduct: %s\tQuantity: %d\tPrice:%f€", categoryName, name, &quantity, &price);

        // Write items into the respective category file
        if (strcmp(categoryName, "INFORMATICS") == 0) {
            fputs(line, pInf);
        } else if (strcmp(categoryName, "ELECTRONICS") == 0) {
            fputs(line, pElec);
        }
    }
    fclose(pFile);
    fclose(pInf);
    fclose(pElec);
}

int main() {
    int choice;
    char name[30], category[30];
    int quantity, newQuantity;
    float price;

    printf("-- Welcome to the Inventory Management System --");

    do {
        // Display menu options
        printf("\nWhat would you like to do?\n");
        printf("1. Add Product\t 2. View Inventory\t 3. Modify Quantity\t 4. Split by Category\t 5. Exit\n");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                // Add a product
                while (1) {
                    printf("Enter the product category (Informatics/Electronics):\n");
                    scanf("%s", category);

                    // Convert category to uppercase
                    for (int i = 0; i < strlen(category); i++) {
                        category[i] = toupper(category[i]);
                    }

                    // Validate category
                    if (strcmp(category, "INFORMATICS") == 0 || strcmp(category, "ELECTRONICS") == 0) {
                        break;
                    } else {
                        printf("Unsupported category. Please try again.\n");
                    }
                }
                printf("Enter the product name:\n");
                scanf("%s", name);
                printf("Enter the quantity of %s in stock:\n", name);
                scanf("%d", &quantity);
                printf("Enter the price per unit:\n");
                scanf("%f", &price);
                addItem(category, name, quantity, price);
                break;

            case 2:
                // View inventory
                printf("Here is your inventory:\n");
                viewInventory();
                break;

            case 3:
                // Modify product quantity
                printf("Enter the product name:\n");
                scanf("%s", name);
                printf("Enter the new quantity:\n");
                scanf("%d", &newQuantity);
                modifyQuantity(name, newQuantity);
                break;

            case 4:
                // Split inventory by category
                splitByCategory();
                break;

            case 5:
                // Exit
                printf("Exiting the program.\n");
                break;

            default:
                printf("Invalid choice. Please try again.\n");
        }
    } while (choice != 5);

    return 0;
}

Feel free to share your feedback or suggest improvements! Let’s learn and grow together. 🚀

Have you built something similar or have ideas to enhance this project? Drop your thoughts in the comments! 💬

Happy coding! 👨‍💻👩‍💻

Davide @sbre