There is no way of escaping literal $ signs in auto_master(5), which

makes for difficulty with hidden Samba shares; shares with $ at the end
of their name.  This enables the use of ${DOLLAR} to work around this.

Reviewed by:		bcr (man page)
Approved by:		trasz
Differential Revision:	https://reviews.freebsd.org/D7048

usr.sbin/autofs/auto_master.5

@@ -27,7 +27,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 13, 2015
+.Dd December 28, 2018
 .Dt AUTO_MASTER 5
 .Os
 .Sh NAME
@@ -187,6 +187,8 @@ Expands to the output of
 .Li "uname -p" .
 .It Li CPU
 Same as ARCH.
+.It Li DOLLAR
+A literal $ sign.
 .It Li HOST
 Expands to the output of
 .Li "uname -n" .

usr.sbin/autofs/defined.c

@@ -266,6 +266,7 @@ defined_init(void)
 
 	defined_add("ARCH", name.machine);
 	defined_add("CPU", name.machine);
+	defined_add("DOLLAR", "$");
 	defined_add("HOST", name.nodename);
 	defined_add("OSNAME", name.sysname);
 	defined_add("OSREL", name.release);