regex(3): Add support for \< and \> word delimiters

Solaris and other OSs have support for \< and \> as word
delimiters in utilities like sed(1). These are useful to
have for general compatiblity with Solaris but should be
avoided for portability with other systems, including the
traditional BSDs.

Bump __FreeBSD_version as this is likely to affect some
userland utilities.

Reference:
https://www.illumos.org/issues/516

PR:		bin/153257
Obtained from:	Illumos
MFC after:	1 month

2 files changed, 25 insertions, 2 deletions

diff --git a/lib/libc/regex/re_format.7 b/lib/libc/regex/re_format.7
index a2a527d..05b1494 100644
--- a/lib/libc/regex/re_format.7
+++ b/lib/libc/regex/re_format.7
@@ -36,7 +36,7 @@
 .\"	@(#)re_format.7	8.3 (Berkeley) 3/20/94
 .\" $FreeBSD$
 .\"
-.Dd March 20, 1994
+.Dd June 30, 2014
 .Dt RE_FORMAT 7
 .Os
 .Sh NAME
@@ -314,6 +314,13 @@ compatible with but not specified by
 .St -p1003.2 ,
 and should be used with
 caution in software intended to be portable to other systems.
+The additional word delimiters  
+.Ql \e<
+and
+.Ql \e> 
+are provided to ease compatibility with traditional
+.Xr svr4 4
+systems but are not portable and should be avoided.
 .Pp
 In the event that an RE could match more than one substring of a given
 string,
diff --git a/lib/libc/regex/regcomp.c b/lib/libc/regex/regcomp.c
index 55f9c04..a01bb95 100644
--- a/lib/libc/regex/regcomp.c
+++ b/lib/libc/regex/regcomp.c
@@ -412,7 +412,17 @@ p_ere_exp(struct parse *p)
 	case '\\':
 		(void)REQUIRE(MORE(), REG_EESCAPE);
 		wc = WGETNEXT();
-		ordinary(p, wc);
+		switch (wc) {
+		case '<':
+			EMIT(OBOW, 0);
+			break;
+		case '>':
+			EMIT(OEOW, 0);
+			break;
+		default:
+			ordinary(p, wc);
+			break;
+		}
 		break;
 	case '{':		/* okay as ordinary except if digit follows */
 		(void)REQUIRE(!MORE() || !isdigit((uch)PEEK()), REG_BADRPT);
@@ -569,6 +579,12 @@ p_simp_re(struct parse *p,
 	case '[':
 		p_bracket(p);
 		break;
+	case BACKSL|'<':
+		EMIT(OBOW, 0);
+		break;
+	case BACKSL|'>':
+		EMIT(OEOW, 0);
+		break;
 	case BACKSL|'{':
 		SETERROR(REG_BADRPT);
 		break;