unalf: actually use timestamps from the alf header (and add -T option to not use them).

1 files changed, 33 insertions, 1 deletions

diff --git a/src/extract.c b/src/extract.c
index 305cd4a..6d940a2 100644
--- a/src/extract.c
+++ b/src/extract.c
@@ -1,5 +1,7 @@
 #include "unalf.h"
 #include "addrs.h"
+#include <time.h>
+#include <utime.h>
 
 int bad_checksum, bad_checksum_count = 0;
 int new_file = 0;
@@ -101,6 +103,32 @@ void fix_filename(void) {
 	}
 }
 
+void set_datetime() {
+	u16 t, d;
+	struct tm tm;
+	time_t time;
+	struct utimbuf utb;
+
+	t = dpeek(alf_hdr_time0);
+	d = dpeek(alf_hdr_date0);
+
+	tm.tm_sec = (t & 0x1f) << 1;
+	tm.tm_hour = t >> 11;
+	if(tm.tm_hour == 24) tm.tm_hour = 0;
+	tm.tm_min = (t >> 5) & 0x3f;
+
+	tm.tm_year = (d >> 9) + 1980 - 1900;
+	tm.tm_mon = ((d >> 5) & 0x0f) - 1;
+	tm.tm_mday = (d & 0x1f);
+
+	time = mktime(&tm);
+
+	if(time != (time_t) -1) {
+		utb.actime = utb.modtime = time;
+		utime(out_filename, &utb); /* ignore errors */
+	}
+}
+
 void make_backup(void) {
 	/* up to 12-char FILENAME.EXT, plus a ~, plus null terminator = 14 */
 	char backup[14];
@@ -162,7 +190,11 @@ void extract_alf(void) {
 			fprintf(stderr, "%s: %s should be %u bytes, but extracted to %u.\n",
 					self, out_filename, getquad(alf_hdr_origsize0), bytes_written);
 
-		if(!opts.extract_to_stdout) fclose(out_file);
+		if(!opts.extract_to_stdout) {
+			fclose(out_file);
+			if(!opts.ignore_datetime)
+				set_datetime();
+		}
 		out_filename = 0;
 	}