Add extremely useful calendar(1) application to FreeBSD

It does extremely useful things like execute sendmail and spew dubiously
accurate factoids.

From the feedback, it seems like it is an essential utility in a modern unix
and not at all a useless bikeshed.  How do those Linux people live without it?
Reverts r358561.

1 files changed, 229 insertions, 0 deletions

diff --git a/usr.bin/calendar/events.c b/usr.bin/calendar/events.c
new file mode 100644
index 000000000000..84f8f2b41a8b
--- /dev/null
+++ b/usr.bin/calendar/events.c
@@ -0,0 +1,229 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 1992-2009 Edwin Groothuis <edwin@FreeBSD.org>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * 
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/time.h>
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#ifdef WITH_ICONV
+#include <iconv.h>
+#include <errno.h>
+#include <langinfo.h>
+
+static iconv_t conv = (iconv_t)-1;
+static char *currentEncoding = NULL;
+
+#endif
+
+#include "pathnames.h"
+#include "calendar.h"
+
+#ifdef WITH_ICONV
+void
+set_new_encoding(void)
+{
+	const char *newenc;
+
+	newenc = nl_langinfo(CODESET);
+	if (currentEncoding == NULL) {
+		currentEncoding = strdup(newenc);
+		if (currentEncoding == NULL)
+			errx(1, "set_new_encoding: cannot allocate memory");
+		return;
+	}
+	if (strcmp(currentEncoding, newenc) == 0)
+		return;
+	free(currentEncoding);
+	currentEncoding = strdup(newenc);
+	if (currentEncoding == NULL)
+		errx(1, "set_new_encoding: cannot allocate memory");
+	if (conv != (iconv_t) -1) {
+		iconv_close(conv);
+		conv = (iconv_t) -1;
+	}
+}
+#endif
+
+static char *
+convert(char *input)
+{
+	char *output;
+#ifdef WITH_ICONV
+	size_t inleft, outleft, converted = 0;
+	char *outbuf, *tmp;
+	char *inbuf;
+	size_t outlen;
+
+	if (currentEncoding == NULL) {
+		output = strdup(input);
+		if (output == NULL)
+			errx(1, "convert: cannot allocate memory");
+		return (output);
+	}
+	if (conv == (iconv_t)-1) {
+		conv = iconv_open(outputEncoding, currentEncoding);
+		if (conv == (iconv_t)-1) {
+			if (errno == EINVAL)
+				errx(1, "Conversion is not supported");
+			else
+				err(1, "Initialization failure");
+		}
+	}
+
+	inleft = strlen(input);
+	inbuf = input;
+
+	outlen = inleft;
+	if ((output = malloc(outlen + 1)) == NULL)
+		errx(1, "convert: cannot allocate memory");
+
+	for (;;) {
+		errno = 0;
+		outbuf = output + converted;
+		outleft = outlen - converted;
+
+		converted = iconv(conv, (char **) &inbuf, &inleft, &outbuf, &outleft);
+		if (converted != (size_t) -1 || errno == EINVAL) {
+			/* finished or invalid multibyte, so truncate and ignore */
+			break;
+		}
+
+		if (errno != E2BIG) {
+			free(output);
+			err(1, "convert");
+		}
+
+		converted = outbuf - output;
+		outlen += inleft * 2;
+
+		if ((tmp = realloc(output, outlen + 1)) == NULL) {
+			free(output);
+			errx(1, "convert: cannot allocate memory");
+		}
+
+		output = tmp;
+		outbuf = output + converted;
+	}
+
+	/* flush the iconv conversion */
+	iconv(conv, NULL, NULL, &outbuf, &outleft);
+
+	/* null terminate the string */
+	*outbuf = '\0';
+#else
+	output = strdup(input);
+	if (output == NULL)
+		errx(1, "convert: cannot allocate memory");
+#endif
+
+	return (output);
+}
+
+struct event *
+event_add(int year, int month, int day, char *date, int var, char *txt,
+    char *extra)
+{
+	struct event *e;
+
+	/*
+	 * Creating a new event:
+	 * - Create a new event
+	 * - Copy the machine readable day and month
+	 * - Copy the human readable and language specific date
+	 * - Copy the text of the event
+	 */
+	e = (struct event *)calloc(1, sizeof(struct event));
+	if (e == NULL)
+		errx(1, "event_add: cannot allocate memory");
+	e->month = month;
+	e->day = day;
+	e->var = var;
+	e->date = convert(date);
+	if (e->date == NULL)
+		errx(1, "event_add: cannot allocate memory");
+	e->text = convert(txt);
+	if (e->text == NULL)
+		errx(1, "event_add: cannot allocate memory");
+	e->extra = NULL;
+	if (extra != NULL && extra[0] != '\0')
+		e->extra = convert(extra);
+	addtodate(e, year, month, day);
+	return (e);
+}
+
+void
+event_continue(struct event *e, char *txt)
+{
+	char *oldtext, *text;
+
+	text = convert(txt);
+	oldtext = e->text;
+	if (oldtext == NULL)
+		errx(1, "event_continue: cannot allocate memory");
+
+	asprintf(&e->text, "%s\n%s", oldtext, text);
+	if (e->text == NULL)
+		errx(1, "event_continue: cannot allocate memory");
+	free(oldtext);
+	free(text);
+
+	return;
+}
+
+void
+event_print_all(FILE *fp)
+{
+	struct event *e;
+
+	while (walkthrough_dates(&e) != 0) {
+#ifdef DEBUG
+		fprintf(stderr, "event_print_allmonth: %d, day: %d\n",
+		    month, day);
+#endif
+
+		/*
+		 * Go through all events and print the text of the matching
+		 * dates
+		 */
+		while (e != NULL) {
+			(void)fprintf(fp, "%s%c%s%s%s%s\n", e->date,
+			    e->var ? '*' : ' ', e->text,
+			    e->extra != NULL ? " (" : "",
+			    e->extra != NULL ? e->extra : "",
+			    e->extra != NULL ? ")" : ""
+			);
+
+			e = e->next;
+		}
+	}
+}