commit bash-20100609 snapshot

doc/bash.1

@@ -5,12 +5,12 @@
 .\"	Case Western Reserve University
 .\"	chet@po.cwru.edu
 .\"
-.\"	Last Change: Sun May 30 17:03:08 EDT 2010
+.\"	Last Change: Sat Jun 12 15:34:58 EDT 2010
 .\"
 .\" bash_builtins, strip all but Built-Ins section
 .if \n(zZ=1 .ig zZ
 .if \n(zY=1 .ig zY
-.TH BASH 1 "2010 May 30" "GNU Bash-4.1"
+.TH BASH 1 "2010 June 12" "GNU Bash-4.1"
 .\"
 .\" There's some problem with having a `@'
 .\" in a tagged paragraph with the BSD man macros.
@@ -2343,9 +2343,13 @@ using arbitrary strings.
 An indexed array is created automatically if any variable is assigned to
 using the syntax \fIname\fP[\fIsubscript\fP]=\fIvalue\fP.  The
 .I subscript
-is treated as an arithmetic expression that must evaluate to a number
-greater than or equal to zero.  To explicitly declare an indexed array,
-use
+is treated as an arithmetic expression that must evaluate to a number.
+If
+.I subscript
+evaluates to a number less than zero, it is used as
+an offset from one greater than the array's maximum index (so a subcript
+of -1 refers to the last element of the array).
+To explicitly declare an indexed array, use
 .B declare \-a \fIname\fP
 (see
 .SM
@@ -2724,9 +2728,13 @@ If \fIlength\fP is omitted, expands to the substring of
 .B
 ARITHMETIC EVALUATION
 below).
-\fIlength\fP must evaluate to a number greater than or equal to zero.
 If \fIoffset\fP evaluates to a number less than zero, the value
 is used as an offset from the end of the value of \fIparameter\fP.
+If \fIlength\fP evaluates to a number less than zero, and \fIparameter\fP
+is not \fB@\fP and not an indexed or associative array, it is interpreted
+as an offset from the end of the value of \fIparameter\fP rather than
+a number of characters, and the expansion is the characters between the
+two offsets.
 If \fIparameter\fP is \fB@\fP, the result is \fIlength\fP positional
 parameters beginning at \fIoffset\fP.
 If \fIparameter\fP is an indexed array name subscripted by @ or *,
@@ -8881,6 +8889,16 @@ changes its behavior to that of version 4.0 with respect to locale-specific
 string comparison when using the conditional command's < and > operators
 and the effect of interrupting a command list.
 .TP 8
+.B compat41
+@item compat41
+If set,
+.BR bash ,
+when in posix mode, treats a single quote in a double-quoted
+parameter expansion as a special character.  The single quotes must match
+(an even number) and the characters between the single quotes are considered
+quoted.  This is the behavior of posix mode through version 4.1.
+The default bash behavior remains as in previous versions.
+.TP 8
 .B dirspell
 If set,
 .B bash