ts: new applet

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

miscutils/ts.c

@@ -0,0 +1,88 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Copyright (C) 2006  Michael Opdenacker <michael@free-electrons.com>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+//config:config TS
+//config:	bool "ts (450 bytes)"
+//config:	default y
+
+//applet:IF_TS(APPLET(ts, BB_DIR_USR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_TS) += ts.o
+
+//usage:#define ts_trivial_usage
+//usage:       "[-is] [STRFTIME]"
+//usage:#define ts_full_usage ""
+
+#include "libbb.h"
+#include "common_bufsiz.h"
+# include <sys/syscall.h>
+
+int ts_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int ts_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
+{
+	struct timespec base;
+	unsigned opt;
+	char *frac;
+	char *fmt_dt2str;
+	char *line;
+
+	opt = getopt32(argv, "^" "is" "\0" "?1" /*max one arg*/);
+	if (opt) {
+		putenv((char*)"TZ=UTC0");
+		tzset();
+	}
+	/*argc -= optind;*/
+	argv += optind;
+	fmt_dt2str = argv[0] ? argv[0]
+		: (char*)(opt ? "%b %d %H:%M:%S"+6 : "%b %d %H:%M:%S");
+	frac = is_suffixed_with(fmt_dt2str, "%.S");
+	if (!frac)
+		frac = is_suffixed_with(fmt_dt2str, "%.s");
+	if (frac) {
+		frac++;
+		strcpy(frac, frac + 1);
+	}
+
+#define date_buf bb_common_bufsiz1
+	setup_common_bufsiz();
+	syscall(__NR_clock_gettime, CLOCK_REALTIME, &base);
+
+	while ((line = xmalloc_fgets(stdin)) != NULL) {
+		struct timespec ts;
+		struct tm tm_time;
+
+		/* libc has incredibly messy way of doing this,
+		 * typically requiring -lrt. We just skip all this mess
+		 */
+		syscall(__NR_clock_gettime, CLOCK_REALTIME, &ts);
+		if (opt) {
+			/* -i and/or -s */
+			struct timespec ts1 = ts1;
+			if (opt & 1) /* -i */
+				ts1 = ts;
+//printf("%d %d\n", ts.tv_sec, base.tv_sec);
+			ts.tv_sec -= base.tv_sec;
+//printf("%d %d\n", ts.tv_sec, base.tv_sec);
+			ts.tv_nsec -= base.tv_nsec;
+			if ((int32_t)(ts.tv_nsec) < 0) {
+				ts.tv_sec--;
+				ts.tv_nsec += 1000*1000*1000;
+			}
+			if (opt & 1) /* -i */
+				base = ts1;
+			localtime_r(&ts.tv_sec, &tm_time);
+		}
+		strftime(date_buf, COMMON_BUFSIZE, fmt_dt2str, &tm_time);
+		if (!frac) {
+			printf("%s %s", date_buf, line);
+		} else {
+			printf("%s.%06u %s", date_buf, (unsigned)ts.tv_nsec / 1000u, line);
+		}
+		free(line);
+	}
+
+	return EXIT_SUCCESS;
+}