1 files changed, 178 insertions, 0 deletions
diff --git a/caln/caln.c b/caln/caln.c
new file mode 100644
index 0000000..5c36db9
--- /dev/null
+++ b/caln/caln.c
@@ -0,0 +1,178 @@
+#include <time.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define DATEFMT "%a %d %b %Y"
+#define SEP " ~> "
+
+typedef struct event {
+	char *name;
+	time_t time;
+} event;
+
+static bool cal = true;
+
+static const char *days[] = {
+	"Su",
+	"Mo",
+	"Tu",
+	"We",
+	"Th",
+	"Fr",
+	"Sa"
+};
+
+static const char *months[] = {
+	"Jan",
+	"Feb",
+	"Mar",
+	"Apr",
+	"May",
+	"Jun",
+	"Jul",
+	"Aug",
+	"Sep",
+	"Oct",
+	"Nov",
+	"Dec"
+};
+
+static const int daysinmonth[] = {
+	31, 28, 31, 30,	31, 30, 31, 31, 30, 31, 30, 31
+};
+
+static bool
+isleap(int year) {
+	if ((year % 4) == 0 && (year % 100) != 0) 
+		return true;
+	else if ((year % 400) == 0)
+		return true;
+	return false;
+}
+
+static void
+print_month(struct tm *t) {
+	printf("      %s %d\n", months[t->tm_mon], t->tm_year + 1900);
+}
+
+static void 
+print_days() {
+	for (int i = 0; i < 7; i++)
+		printf("%s ", days[i]);
+	putchar('\n');
+}
+
+static void 
+print_padded(int n, int l) {
+	int i = 1;
+loop:
+	if ((n / i) > 0) {
+		i *= 10;
+		l--;
+		goto loop;
+	}
+
+	if (l != 0)
+		printf("%*s", l, " ");
+	if (l < 0)
+		return;
+
+	printf("%d", n);
+}
+
+static void 
+print_month_grid(struct tm *t) {
+	int day = 1;
+	int total = daysinmonth[t->tm_mon];
+	if (t->tm_mon == 1 && isleap(t->tm_year + 1900))
+		total += 1;
+
+	int offset = (t->tm_yday % 7) - 1;
+	for (int i = 0; i < offset; i++)
+		printf("   ");
+
+	for (; day < total + 1; day++) {
+		if (day == t->tm_mday) {
+			printf("\e[4;34m");	
+			print_padded(day, 2);
+			printf("\e[0m");	
+		} else
+			print_padded(day, 2);
+		putchar(' ');
+		if (((day + offset) % 7) == 0)
+			putchar('\n');
+	}
+	putchar('\n');
+}
+
+static void 
+print_cal(struct tm *t) {
+	print_month(t);
+	print_days();
+	print_month_grid(t);
+}
+
+static event *
+read_event(FILE *f) {
+	event *e = malloc(sizeof(event));
+	char buf[256] = {0};
+	if (!fgets(buf, 256, f)) {
+		free(e);
+		return NULL;
+	}
+	char *time = buf;
+	char *name = strchr(buf, '|');
+	if (!name) {
+		fprintf(stderr, "invalid event! %s\n", buf);
+		exit(1);
+	}
+	*name = 0;
+	name++;
+
+	e->name = strdup(name);	
+	e->time = atoll(time);
+	return e;
+}
+
+static void 
+print_event(event *e) {
+	struct tm *t = localtime(&e->time);
+	char buf[256];
+	strftime(buf, 256, DATEFMT, t);
+	printf("%s" SEP "%s", buf, e->name);
+}
+
+static void
+free_event(event *e) {
+	free(e->name);
+	free(e);
+}
+
+int 
+main(int argc, char **argv) {
+	if (argc > 1)
+		if (strcmp(argv[1], "-h") == 0)
+			cal = false;
+
+	time_t ulocal = time(NULL);
+	struct tm *local = localtime(&ulocal);
+
+	if (cal)
+		print_cal(local);
+
+	bool dirty = false;
+	event *e;
+	while (e = read_event(stdin)) {
+		if (ulocal + (86400 * 30) > e->time) {
+			print_event(e);
+			dirty = true;
+		}
+		free_event(e);
+	}
+	if (!dirty)
+		printf("You have nothing upcoming\n");
+
+	return 0;
+}