Initial

1 files changed, 65 insertions, 0 deletions

diff --git a/strftime.c b/strftime.c
new file mode 100644
index 0000000..70d171b
--- /dev/null
+++ b/strftime.c
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2023 Mitchell Riedstra
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ *
+ * A fairly basic interface to `strftime`, since dates are apparently difficult
+ * to handle with regular command line utilites and the POSIX spec for `date`
+ * is rather lacking.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <errno.h>
+
+
+void
+help()
+{
+	puts("strftime <fmt> [timestamp]");
+	exit(1);
+}
+
+int
+main(int argc, char **argv) {
+	time_t t = time(NULL);
+	char **a = argv+1;
+	struct tm *tm;
+	char *fmt;
+	char out[256] = {0};
+
+	if (!*a) {
+		help();
+	}
+
+	fmt = *a;
+	a++;
+
+	if (*a) {
+		errno = 0;
+		t = strtol(*a, NULL, 10);
+		if (errno != 0) {
+			perror("strtol");
+			exit(1);
+		}
+	}
+
+	tm = localtime(&t);
+
+	if (strftime(out, 256, fmt, tm) == 0) {
+		perror("strftime");
+		exit(1);
+	}
+
+	puts(out);
+}