Initial Commit of sccash

sccash.c

@@ -0,0 +1,197 @@
+/*
+ * sccash - Simple C Cash
+ * A lightweight CLI currency converter for USD, JPY, and EUR
+ * Compile: gcc -o sccash sccash.c
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+#define RATE_USD_JPY 159.67
+#define RATE_USD_EUR 0.866
+#define RATE_EUR_JPY 184.20
+
+typedef enum {
+    CURRENCY_USD,
+    CURRENCY_JPY,
+    CURRENCY_EUR,
+    CURRENCY_INVALID
+} Currency;
+
+const char* currency_names[] = {"USD", "JPY", "EUR"};
+
+Currency parse_currency(const char* input) {
+    char upper[4] = {0};
+    for (int i = 0; i < 3 && input[i]; i++) {
+        upper[i] = toupper(input[i]);
+    }
+    
+    if (strcmp(upper, "USD") == 0) return CURRENCY_USD;
+    if (strcmp(upper, "JPY") == 0) return CURRENCY_JPY;
+    if (strcmp(upper, "EUR") == 0) return CURRENCY_EUR;
+    return CURRENCY_INVALID;
+}
+
+double convert_to_usd(double amount, Currency from) {
+    switch (from) {
+        case CURRENCY_USD: return amount;
+        case CURRENCY_JPY: return amount / RATE_USD_JPY;
+        case CURRENCY_EUR: return amount / RATE_USD_EUR;
+        default: return 0.0;
+    }
+}
+
+double convert_from_usd(double usd_amount, Currency to) {
+    switch (to) {
+        case CURRENCY_USD: return usd_amount;
+        case CURRENCY_JPY: return usd_amount * RATE_USD_JPY;
+        case CURRENCY_EUR: return usd_amount * RATE_USD_EUR;
+        default: return 0.0;
+    }
+}
+
+double convert_currency(double amount, Currency from, Currency to) {
+    if (from == to) return amount;
+    double usd_amount = convert_to_usd(amount, from);
+    return convert_from_usd(usd_amount, to);
+}
+
+void print_table_header(void) {
+    printf("+--------+---------------+--------+----------------+\n");
+    printf("|  FROM  |    AMOUNT     |   TO   |  CONVERTED     |\n");
+    printf("+--------+---------------+--------+----------------+\n");
+}
+
+void print_table_row(const char* from, double amount, const char* to, double converted) {
+    printf("| %-6s | %13.2f | %-6s | %14.2f |\n", from, amount, to, converted);
+}
+
+void print_table_footer(void) {
+    printf("+--------+---------------+--------+----------------+\n");
+}
+
+void print_all_conversions(double amount, Currency from) {
+    printf("\n");
+    print_table_header();
+    
+    for (int i = 0; i < 3; i++) {
+        if (i != from) {
+            Currency to = (Currency)i;
+            double result = convert_currency(amount, from, to);
+            print_table_row(currency_names[from], amount, currency_names[to], result);
+        }
+    }
+    
+    print_table_footer();
+    printf("\nExchange Rates (as of March 26, 2026):\n");
+    printf("  1 USD = %.2f JPY\n", RATE_USD_JPY);
+    printf("  1 USD = %.3f EUR\n", RATE_USD_EUR);
+    printf("  1 EUR = %.2f JPY\n", RATE_EUR_JPY);
+    printf("\n");
+}
+
+void interactive_mode(void) {
+    char from_input[10], to_input[10];
+    double amount;
+    Currency from, to;
+    
+    printf("\n=== sccash - Simple C Cash ===\n\n");
+    printf("Available currencies: USD, JPY, EUR\n\n");
+    
+    printf("Enter amount: ");
+    if (scanf("%lf", &amount) != 1 || amount < 0) {
+        fprintf(stderr, "Error: Invalid amount\n");
+        return;
+    }
+    
+    printf("Convert from (USD/JPY/EUR): ");
+    scanf("%9s", from_input);
+    from = parse_currency(from_input);
+    
+    if (from == CURRENCY_INVALID) {
+        fprintf(stderr, "Error: Invalid currency '%s'\n", from_input);
+        return;
+    }
+    
+    printf("Convert to (USD/JPY/EUR): ");
+    scanf("%9s", to_input);
+    to = parse_currency(to_input);
+    
+    if (to == CURRENCY_INVALID) {
+        fprintf(stderr, "Error: Invalid currency '%s'\n", to_input);
+        return;
+    }
+    
+    if (from == to) {
+        printf("\nResult: %.2f %s (same currency)\n", amount, currency_names[from]);
+        return;
+    }
+    
+    double result = convert_currency(amount, from, to);
+    
+    printf("\n");
+    print_table_header();
+    print_table_row(currency_names[from], amount, currency_names[to], result);
+    print_table_footer();
+    printf("\n");
+    
+    printf("Show all conversions? (y/n): ");
+    char show_all[10];
+    scanf("%9s", show_all);
+    if (show_all[0] == 'y' || show_all[0] == 'Y') {
+        print_all_conversions(amount, from);
+    }
+}
+
+void cli_mode(int argc, char* argv[]) {
+    if (argc < 4) {
+        fprintf(stderr, "Usage: %s <amount> <from> <to>\n", argv[0]);
+        fprintf(stderr, "  amount: numeric value to convert\n");
+        fprintf(stderr, "  from:   source currency (USD, JPY, EUR)\n");
+        fprintf(stderr, "  to:     target currency (USD, JPY, EUR)\n\n");
+        fprintf(stderr, "Example: %s 100 USD JPY\n", argv[0]);
+        fprintf(stderr, "Or run without arguments for interactive mode\n");
+        exit(1);
+    }
+    
+    double amount = atof(argv[1]);
+    if (amount <= 0) {
+        fprintf(stderr, "Error: Invalid amount '%s'\n", argv[1]);
+        exit(1);
+    }
+    
+    Currency from = parse_currency(argv[2]);
+    Currency to = parse_currency(argv[3]);
+    
+    if (from == CURRENCY_INVALID) {
+        fprintf(stderr, "Error: Invalid source currency '%s'\n", argv[2]);
+        fprintf(stderr, "Available: USD, JPY, EUR\n");
+        exit(1);
+    }
+    
+    if (to == CURRENCY_INVALID) {
+        fprintf(stderr, "Error: Invalid target currency '%s'\n", argv[3]);
+        fprintf(stderr, "Available: USD, JPY, EUR\n");
+        exit(1);
+    }
+    
+    double result = convert_currency(amount, from, to);
+    
+    printf("\n");
+    print_table_header();
+    print_table_row(currency_names[from], amount, currency_names[to], result);
+    print_table_footer();
+    printf("\n");
+}
+
+int main(int argc, char* argv[]) {
+    if (argc == 1) {
+        interactive_mode();
+    } else {
+        cli_mode(argc, argv);
+    }
+    
+    return 0;
+}