2 files changed, 44 insertions, 2 deletions

diff --git a/lib/libc/stdtime/strptime.3 b/lib/libc/stdtime/strptime.3
index 8e74a1327bd3..99568c95f2b7 100644
--- a/lib/libc/stdtime/strptime.3
+++ b/lib/libc/stdtime/strptime.3
@@ -23,7 +23,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $Id: strptime.3,v 1.3 1999/04/25 01:42:18 wes Exp $
+.\" $Id: strptime.3,v 1.4 1999/04/25 07:28:39 wes Exp $
 .\" "
 .Dd May 8, 1997
 .Dt STRPTIME 3
@@ -44,6 +44,7 @@ according to the string pointed to by
 .Fa format ,
 and fills in the elements of the structure pointed to by
 .Fa timeptr .
+The resulting values will be relative to the local time zone.
 Thus, it can be considered the reverse operation of
 .Xr strftime 3 .
 .Pp
@@ -91,3 +92,13 @@ The
 .Fn strptime
 function appeared in
 .Fx 3.0 .
+.Pp
+.Sh BUGS
+The
+.Fa %Z
+format specifier only accepts time zone abbreviations of the local time zone,
+or the value "GMT".
+This limitation is because of ambiguity due to of the over loading of time
+zone abbreviations.  One such example is
+.Fa EST
+which is both Eastern Standard Time and Eastern Australia Summer Time.
diff --git a/lib/libc/stdtime/strptime.c b/lib/libc/stdtime/strptime.c
index 27437fe31f2f..34da06e713bd 100644
--- a/lib/libc/stdtime/strptime.c
+++ b/lib/libc/stdtime/strptime.c
@@ -53,7 +53,7 @@
 
 #ifdef LIBC_RCS
 static const char rcsid[] =
-	"$Id: strptime.c,v 1.5 1999/04/25 01:42:18 wes Exp $";
+	"$Id: strptime.c,v 1.6 1999/04/25 07:28:39 wes Exp $";
 #endif
 
 #ifndef lint
@@ -71,6 +71,8 @@ static char sccsid[] = "@(#)strptime.c	0.1 (Powerdog) 94/03/27";
 
 #define asizeof(a)	(sizeof (a) / sizeof ((a)[0]))
 
+static int got_GMT = 0;
+
 char *
 strptime(const char *buf, const char *fmt, struct tm *tm)
 {
@@ -344,8 +346,37 @@ strptime(const char *buf, const char *fmt, struct tm *tm)
 				while (*ptr != 0 && !isspace((unsigned char)*ptr))
 					ptr++;
 			break;
+
+		case 'Z':
+			{
+			const char *cp;
+			char *zonestr;
+
+			for (cp = buf; *cp && isupper(*cp); ++cp) {/*empty*/}
+			if (cp - buf) {
+				zonestr = alloca(cp - buf + 1);
+				strncpy(zonestr, buf, cp - buf);
+				zonestr[cp - buf] = '\0';
+				tzset();
+				if (0 == strcmp(zonestr, "GMT")) {
+					got_GMT = 1;
+				} else if (0 == strcmp(zonestr, tzname[0])) {
+					tm->tm_isdst = 0;
+				} else if (0 == strcmp(zonestr, tzname[1])) {
+					tm->tm_isdst = 1;
+				} else {
+					return 0;
+				}
+				buf += cp - buf;
+			}
+			}
+			break;
 		}
 	}
 
+	if (got_GMT) {
+		time_t t = timegm(tm);
+		localtime_r(&t, tm);
+	}
 	return (char *)buf;
 }