From owner-svn-src-stable@FreeBSD.ORG  Sun Sep 19 21:38:12 2010
Return-Path: <owner-svn-src-stable@FreeBSD.ORG>
Delivered-To: svn-src-stable@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id E498E106564A;
	Sun, 19 Sep 2010 21:38:12 +0000 (UTC)
	(envelope-from jilles@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c])
	by mx1.freebsd.org (Postfix) with ESMTP id B88AC8FC12;
	Sun, 19 Sep 2010 21:38:12 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id o8JLcCvb017474;
	Sun, 19 Sep 2010 21:38:12 GMT (envelope-from jilles@svn.freebsd.org)
Received: (from jilles@localhost)
	by svn.freebsd.org (8.14.3/8.14.3/Submit) id o8JLcCpC017472;
	Sun, 19 Sep 2010 21:38:12 GMT (envelope-from jilles@svn.freebsd.org)
Message-Id: <201009192138.o8JLcCpC017472@svn.freebsd.org>
From: Jilles Tjoelker <jilles@FreeBSD.org>
Date: Sun, 19 Sep 2010 21:38:12 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
	svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org
X-SVN-Group: stable-8
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Cc: 
Subject: svn commit: r212884 - stable/8/bin/sh
X-BeenThere: svn-src-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: SVN commit messages for all the -stable branches of the src tree
	<svn-src-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-stable>, 
	<mailto:svn-src-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-stable>
List-Post: <mailto:svn-src-stable@freebsd.org>
List-Help: <mailto:svn-src-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-stable>,
	<mailto:svn-src-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 19 Sep 2010 21:38:13 -0000

Author: jilles
Date: Sun Sep 19 21:38:12 2010
New Revision: 212884
URL: http://svn.freebsd.org/changeset/base/212884

Log:
  MFC r211621: sh(1): Add a brief summary of arithmetic expressions.

Modified:
  stable/8/bin/sh/sh.1
Directory Properties:
  stable/8/bin/sh/   (props changed)

Modified: stable/8/bin/sh/sh.1
==============================================================================
--- stable/8/bin/sh/sh.1	Sun Sep 19 20:38:34 2010	(r212883)
+++ stable/8/bin/sh/sh.1	Sun Sep 19 21:38:12 2010	(r212884)
@@ -1148,7 +1148,7 @@ Quote Removal.
 The
 .Ql $
 character is used to introduce parameter expansion, command
-substitution, or arithmetic evaluation.
+substitution, or arithmetic expansion.
 .Ss Tilde Expansion (substituting a user's home directory)
 A word beginning with an unquoted tilde character
 .Pq Ql ~
@@ -1363,10 +1363,41 @@ The
 shell expands all tokens in the
 .Ar expression
 for parameter expansion,
-command substitution, and quote removal.
+command substitution,
+arithmetic expansion
+and quote removal.
+.Pp
+The allowed expressions are a subset of C expressions,
+summarized below.
+.Bl -tag -width "Variables" -offset indent
+.It Values
+All values are of type
+.Ft intmax_t .
+.It Constants
+Decimal, octal (starting with
+.Li 0 )
+and hexadecimal (starting with 
+.Li 0x )
+integer constants.
+.It Variables
+Shell variables can be read and written
+and contain integer constants.
+.It Unary operators
+.Li "! ~ + -"
+.It Binary operators
+.Li "* / % + - << >> < <= > >= == != & ^ | && ||"
+.It Assignment operators
+.Li "= += -= *= /= %= <<= >>= &= ^= |="
+.It Short-circuit evaluation
+The
+.Li &&
+and
+.Li ||
+operators always evaluate both sides.
+This is a bug.
+.El
 .Pp
-Next, the shell treats this as an arithmetic expression and
-substitutes the value of the expression.
+The result of the expression is substituted in decimal.
 .Ss White Space Splitting (Field Splitting)
 After parameter expansion, command substitution, and
 arithmetic expansion the shell scans the results of