[PATCH] stat: print nanoseconds immediately after seconds

[Dmitry Savelyev]

* util.c: Implement a new sprinttime_nsec function for printing time_t
and nanoseconds at once.
* defs.h: Prototype for the above.
* statx.c: Use it.
* print_struct_stat.c: Likewise.
* tests/print_time.c: Separate time_t printing functions with and
without nanoseconds.
* tests/tests.h: Prototype for the non-nanosecond function.
* tests/utime.c: Use the non-nanosecond function.
---
 defs.h              |  1 +
 print_struct_stat.c |  4 +---
 statx.c             |  4 +---
 tests/print_time.c  | 23 +++++++++++++++++++++--
 tests/tests.h       |  3 +++
 tests/utime.c       |  4 ++--
 util.c              | 24 ++++++++++++++++++++++++
 7 files changed, 53 insertions(+), 10 deletions(-)

diff --git a/defs.h b/defs.h
index b2be75b9..28a82020 100644
--- a/defs.h
+++ b/defs.h
@@ -546,6 +546,7 @@ extern void addflags(const struct xlat *, uint64_t);
 extern int printflags64(const struct xlat *, uint64_t, const char *);
 extern const char *sprintflags(const char *, const struct xlat *, uint64_t);
 extern const char *sprinttime(time_t);
+extern const char *sprinttime_nsec(time_t, unsigned long long);
 extern void print_symbolic_mode_t(unsigned int);
 extern void print_numeric_umode_t(unsigned short);
 extern void print_numeric_long_umask(unsigned long);
diff --git a/print_struct_stat.c b/print_struct_stat.c
index b5e0167e..7317328c 100644
--- a/print_struct_stat.c
+++ b/print_struct_stat.c
@@ -67,9 +67,7 @@ print_struct_stat(struct tcb *tcp, const struct strace_stat *const st)
 	if (!abbrev(tcp)) {
 #define PRINT_ST_TIME(field)				\
 	tprints(", st_" #field "=");			\
-	tprints(sprinttime(st->field));			\
-	if (st->field ## _nsec)				\
-		tprintf(".%09llu", st->field ## _nsec)
+	tprints(sprinttime_nsec(st->field, st->field ## _nsec));
 
 		PRINT_ST_TIME(atime);
 		PRINT_ST_TIME(mtime);
diff --git a/statx.c b/statx.c
index 7c647fa3..9a9751f0 100644
--- a/statx.c
+++ b/statx.c
@@ -60,9 +60,7 @@ SYS_FUNC(statx)
 #define PRINT_FIELD_TIME(field)						\
 	do {								\
 		tprints(", " #field "=");				\
-		tprints(sprinttime(stx.field.sec));			\
-		if (stx.field.nsec)					\
-			tprintf(".%09" PRId32, stx.field.nsec);		\
+		tprints(sprinttime_nsec(stx.field.sec, stx.field.nsec)); \
 	} while (0)
 
 		struct_statx stx;
diff --git a/tests/print_time.c b/tests/print_time.c
index 3d5b5545..561fc031 100644
--- a/tests/print_time.c
+++ b/tests/print_time.c
@@ -32,7 +32,7 @@
 #include <time.h>
 
 void
-print_time_t_nsec(const time_t t, const unsigned long long nsec)
+print_time_t(const time_t t)
 {
 	if (t) {
 		const struct tm *const p = localtime(&t);
@@ -47,8 +47,27 @@ print_time_t_nsec(const time_t t, const unsigned long long nsec)
 	} else {
 		putchar('0');
 	}
+}
+
+void
+print_time_t_nsec(const time_t t, const unsigned long long nsec)
+{
+	if (t) {
+		const struct tm *const p = localtime(&t);
+		char buf[256];
+
+		if(!p) {
+			perror_msg_and_fail("localtime");
+		}
+
+		strftime(buf, sizeof(buf), "%FT%T", p);
+		fputs(buf, stdout);
 
-	if (nsec) {
 		printf(".%09llu", nsec);
+
+		strftime(buf, sizeof(buf), "%z", p);
+		fputs(buf, stdout);
+	} else {
+		putchar('0');
 	}
 }
diff --git a/tests/tests.h b/tests/tests.h
index d077c5c8..6f94b692 100644
--- a/tests/tests.h
+++ b/tests/tests.h
@@ -119,6 +119,9 @@ void print_quoted_string(const char *);
 /* Print memory in a quoted form. */
 void print_quoted_memory(const char *, size_t);
 
+/* Print time_t in symbolic format. */
+void print_time_t(time_t);
+
 /* Print time_t and nanoseconds in symbolic format. */
 void print_time_t_nsec(time_t, unsigned long long);
 
diff --git a/tests/utime.c b/tests/utime.c
index ba8ae326..7c9b6087 100644
--- a/tests/utime.c
+++ b/tests/utime.c
@@ -69,9 +69,9 @@ main(void)
 	rc = k_utime("utime\nfilename", tail_u);
 	const char *errstr = sprintrc(rc);
 	printf("utime(\"utime\\nfilename\", {actime=");
-	print_time_t_nsec(t, 0);
+	print_time_t(t);
 	printf(", modtime=");
-	print_time_t_nsec(t, 0);
+	print_time_t(t);
 	printf("}) = %s\n", errstr);
 
 	puts("+++ exited with 0 +++");
diff --git a/util.c b/util.c
index 9144efb6..bb7c7883 100644
--- a/util.c
+++ b/util.c
@@ -563,6 +563,30 @@ sprinttime(time_t t)
 	return buf;
 }
 
+const char *
+sprinttime_nsec(time_t t, unsigned long long nsec)
+{
+	struct tm *tmp;
+	static char buf[sizeof(int) * 3 * 6 + sizeof(unsigned long long) * 3 +
+	                sizeof("+0000")];
+
+	if(t == 0 && nsec == 0) {
+		strcpy(buf, "0");
+		return buf;
+	}
+	tmp = localtime(&t);
+	if(tmp) {
+		size_t len = strftime(buf, sizeof(buf), "%FT%T", tmp);
+		len += snprintf(buf + len, sizeof(buf) - len, ".%09llu",
+		                nsec);
+		strftime(buf + len, sizeof(buf) - len, "%z", tmp);
+	} else
+		snprintf(buf, sizeof(buf), "%lu.%09llu", (unsigned long) t,
+		         nsec);
+
+	return buf;
+}
+
 enum sock_proto
 getfdproto(struct tcb *tcp, int fd)
 {
-- 
2.12.1