Source files.

src/main.c

@@ -0,0 +1,101 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "main.h"
+
+int main(int argc, char **argv) {
+    arguments_t * args = parse_arguments(argc, argv);
+
+    printf("%.2Lf\n", (args->price * args->wattage) * args->interval);
+
+    free(args);
+    return 0;
+}
+
+arguments_t * parse_arguments(int argc, char **argv) {
+    if (argc == 1) {
+        print_usage();
+        exit(0);
+    }
+
+    arguments_t *args = (arguments_t *)calloc(1, sizeof(arguments_t));
+    int pos_args_pos = 0;
+
+    for (int i = 1; i < argc; ++i) {
+        if (argv[i][0] == '-') {
+            if (argv[i][1] == 'h' || argv[i][2] == 'h') {
+                print_usage();
+                exit(0);
+            } else if (argv[i][1] == 'v' || argv[i][2] == 'v') {
+                print_version();
+                exit(0);
+            }
+        } else if (pos_args_pos == 0) {
+            args->price = to_wattpersecond((price_t)atof(argv[i]));
+            pos_args_pos++;
+        } else if (pos_args_pos == 1) {
+            args->wattage = atof(argv[i]);
+            pos_args_pos++;
+        } else if (pos_args_pos > 1) {
+            args->interval += to_seconds(argv[i]);
+            pos_args_pos++;
+        }
+    }
+
+    printf("%d\n", pos_args_pos);
+
+    if (pos_args_pos < 3) {
+        print_usage();
+        exit(1);
+    }
+
+    return args;
+}
+
+interval_t to_seconds(char *interval) {
+    interval_t intrvl = (interval_t)atol(interval);
+    char unit = interval[strlen(interval) - 1];
+
+    if (!(unit >= '0' && unit <= '9'))
+        switch (unit) {
+            case 'm':
+            case 'M':
+                return intrvl * 60;
+            case 'h':
+            case 'H':
+                return intrvl * 60 * 60;
+            case 'd':
+            case 'D':
+                return intrvl * 60 * 60 * 24;
+        }
+    return intrvl;
+}
+
+inline price_t to_wattpersecond(price_t price) {
+    return price / 1000.f / 3600.f;
+}
+
+void print_version() {
+    printf("kwh-calc Ver. " VERSION "\n"
+           "Copyright (C) 2021 Alexander \"Arav\" Andreev <me@arav.top>. All rights reserved.\n"
+           "The software is provided \"AS IS\", without WARRANTY of ANY KIND, EXPRESS or\n"
+           "IMPLIED, including but not limited to the WARRANTIES of MERCHANTABILITY, fitness\n"
+           "for a PARTICULAR PURPOSE and NONINFRINGEMENT.\n"
+           "See LICENSE file, containing a text of MIT+NIGGER license, that comes with\n"
+           "the source code for a full text.\n");
+}
+
+void print_usage() {
+    printf("Usage: kwh-calc [options] price wattage interval [interval ...]\n"
+           "Options:\n"
+           "  --help, -h    Display this usage information.\n"
+           "  --version, -v Display program version.\n"
+           "Arguments:\n"
+           "  price    Price per KWh.\n"
+           "  wattage  Specify power usage in Watts.\n"
+           "  interval Time interval in seconds total cost to be calculated for.\n"
+           "           You may specify other time units such as:\n"
+           "           m'imute, h'our, d'ay. Example: 5d 3h.\n"
+           "           All given intervals will be summed up.\n");
+}

src/main.h

@@ -0,0 +1,27 @@
+#ifndef _MAIN_H_
+#define _MAIN_H_
+
+#define VERSION "1.0.0"
+
+typedef long double   price_t;
+typedef long double   wattage_t;
+typedef unsigned long interval_t;
+
+typedef struct {
+    price_t    price;
+    wattage_t  wattage;
+    interval_t interval;
+} arguments_t;
+
+arguments_t *parse_arguments(int argc, char **argv);
+
+
+interval_t to_seconds(char *interval);
+inline price_t to_wattpersecond(price_t price);
+
+
+void print_version();
+void print_usage();
+
+
+#endif