Improve style and license

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 61 insertions, 0 deletions

diff --git a/alarm.c b/alarm.c
new file mode 100644
index 0000000..81ad107
--- /dev/null
+++ b/alarm.c
@@ -0,0 +1,61 @@
+/* See LICENSE file for copyright and license details. */
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+
+static char *argv0;
+
+static void
+usage(void)
+{
+	fprintf(stderr, "usage: %s duration command [argument ...]\n", argv0);
+	exit(0);
+}
+
+int
+main(int argc, char **argv)
+{
+	long hours = 0;
+	long minutes = 0;
+	long seconds = 0;
+	long buf = 0;
+	int hms = 0;
+	char *time, c;
+
+	argv0 = argv[0];
+	if (argc < 3)
+		usage();
+
+	time = argv[1];
+	while ((c = *time++)) {
+		if (isdigit(c)) {
+			buf = buf * 10 - (c & 15);
+		} else if (strchr("hms", c)) {
+			if      (c == 'h')  hours   = -buf;
+			else if (c == 'm')  minutes = -buf;
+			else if (c == 's')  seconds = -buf;
+			buf = 0, hms = 1;
+		} else {
+			usage();
+		}
+	}
+	if (!hms) {
+		if (strlen(argv[1]) < 1)
+			return 0;
+		seconds = -buf;
+	}
+
+	seconds += minutes * 60;
+	seconds += hours * 60 * 60;
+	if (seconds < 1 || 65535 < seconds)
+		usage();
+
+	alarm((unsigned)seconds);
+	execvp(argv[2], &argv[2]);
+	fprintf(stderr, "%s: execvp %s: %s\n", argv0, argv[2], strerror(ENOMEM));
+	return 1;
+}