There are equivalents for '+' and '?' in BRE.
OK?
martijn@
Index: re_format.7
===================================================================
RCS file: /cvs/src/lib/libc/regex/re_format.7,v
retrieving revision 1.22
diff -u -p -r1.22 re_format.7
--- re_format.7 14 Sep 2015 20:06:58 -0000 1.22
+++ re_format.7 6 Jul 2021 08:59:28 -0000
@@ -524,13 +524,6 @@ or
Basic regular expressions differ in several respects:
.Bl -bullet -offset 3n
.It
-.Sq | ,
-.Sq + ,
-and
-.Sq ?\&
-are ordinary characters and there is no equivalent
-for their functionality.
-.It
The delimiters for bounds are
.Sq \e{
and
@@ -540,6 +533,20 @@ with
and
.Sq }
by themselves ordinary characters.
+.It
+.Sq | ,
+.Sq + ,
+and
+.Sq ?\&
+are ordinary characters.
+.Sq \e{1,\e}
+is equivalent to
+.Sq + .
+.Sq \e{0,1\e}
+is equivalent to
+.Sq ?\& .
+There is no equivalent for
+.Sq | .
.It
The parentheses for nested subexpressions are
.Sq \e(
