First commit

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

1 files changed, 58 insertions, 0 deletions

diff --git a/libpatch_create_timestamp.c b/libpatch_create_timestamp.c
new file mode 100644
index 0000000..54b6d91
--- /dev/null
+++ b/libpatch_create_timestamp.c
@@ -0,0 +1,58 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+size_t
+libpatch_create_timestamp(char *buf, size_t bufsize, const struct tm *tm,
+                          uintmax_t subseconds, unsigned subseconds_decimals, 
+                          unsigned frac, int zone, enum libpatch_style style)
+{
+	size_t guess, len, r;
+	const char *fmt;
+
+	frac = MIN(frac, subseconds_decimals);
+
+	if (style == LIBPATCH_STYLE_COPIED) {
+		fmt = "%a %b %e %T %Y";
+		guess = sizeof("aaa bbb 00 00:00:00 0000");
+	} else if (style == LIBPATCH_STYLE_UNIFIED) {
+		fmt = "%Y-%m-%d %H:%M:%S";
+		zone = 1;
+		guess = sizeof("0000-00-00 00:00:00");
+	} else {
+		errno = EINVAL;
+		return 0;
+	}
+
+	if (zone)
+		guess += sizeof(" +0000");
+	guess += (size_t)frac + (size_t)(frac > 0);
+
+	if (!bufsize)
+		return guess;
+
+	while (subseconds_decimals != frac) {
+		subseconds /= 10;
+		subseconds_decimals -= 1;
+	}
+
+	len = strftime(buf, bufsize, fmt, tm);
+	if (!len)
+		return bufsize < guess ? guess : bufsize + 16U;
+
+	if (frac) {
+		if (len < bufsize)
+			snprintf(&buf[len], bufsize - len, ".%0*ju", (int)frac, subseconds);
+		len += (size_t)frac + (size_t)(frac > 0);
+	}
+
+	if (zone) {
+		if (len < bufsize)
+			return bufsize < len + 7U ? len + 7U : bufsize + 16U;
+		len += r = strftime(&buf[len], bufsize - len, " %z", tm);
+		if (!r)
+			return bufsize < len + 7U ? len + 7U : bufsize + 16U;
+	}
+
+	return len + 1;
+}