lib9: add ctime

ctime differs across Unix vs Plan 9 so add to portability library

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5363043

include/libc.h

@@ -95,6 +95,7 @@ extern	void	perror(const char*);
 extern	int	postnote(int, int, char *);
 extern	double	p9pow10(int);
 extern	char*	searchpath(char*);
+extern	char*	p9ctime(long);
 #define p9setjmp(b)	sigsetjmp((void*)(b), 1)
 
 extern	void	sysfatal(char*, ...);
@@ -115,6 +116,7 @@ extern	void	sysfatal(char*, ...);
 #undef  strtod
 #define strtod		fmtstrtod
 #define charstod	fmtcharstod
+#define ctime	p9ctime
 #endif
 
 /*

src/cmd/gopack/ar.c

@@ -1420,15 +1420,12 @@ void
 longt(Armember *bp)
 {
 	char *cp;
-	time_t date;
 
 	pmode(strtoul(bp->hdr.mode, 0, 8));
 	Bprint(&bout, "%3ld/%1ld", strtol(bp->hdr.uid, 0, 0), strtol(bp->hdr.gid, 0, 0));
 	Bprint(&bout, "%7ld", bp->size);
-	date = bp->date;
-	cp = ctime(&date);
-	/* using unix ctime, not plan 9 time, so cp+20 for year, not cp+24 */
-	Bprint(&bout, " %-12.12s %-4.4s ", cp+4, cp+20);
+	cp = ctime(bp->date);
+	Bprint(&bout, " %-12.12s %-4.4s ", cp+4, cp+24);
 }
 
 int	m1[] = { 1, ROWN, 'r', '-' };

src/lib9/Makefile

@@ -57,6 +57,7 @@ LIB9OFILES=\
 	atoi.$O\
 	cleanname.$O\
 	create.$O\
+	ctime.$O\
 	dirfstat.$O\
 	dirfwstat.$O\
 	dirstat.$O\

src/lib9/ctime.c

+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#define NOPLAN9DEFINES
+#include <u.h>
+#include <libc.h>
+
+char*
+p9ctime(long t)
+{
+	static char buf[100];
+	time_t tt;
+	struct tm *tm;
+	
+	tt = t;
+	tm = localtime(&tt);
+	snprint(buf, sizeof buf, "%3.3s %3.3s %02d %02d:%02d:%02d %3.3s %d\n",
+		"SunMonTueWedThuFriSat"+(tm->tm_wday*3),
+		"JanFebMarAprMayJunJulAugSepOctNovDec"+(tm->tm_mon*3),
+		tm->tm_mday,
+		tm->tm_hour,
+		tm->tm_min,
+		tm->tm_sec,
+		tm->tm_zone,
+		tm->tm_year + 1900);
+	return buf;
+}