commit bash-20170331 snapshot

doc/bashref.texi

@@ -508,7 +508,7 @@ double quote
 question mark
 @item \@var{nnn}
 the eight-bit character whose value is the octal value @var{nnn}
-(one to three digits)
+(one to three octal digits)
 @item \x@var{HH}
 the eight-bit character whose value is the hexadecimal value @var{HH}
 (one or two hex digits)
@@ -659,8 +659,13 @@ the time information.
 If the pipeline is not executed asynchronously (@pxref{Lists}), the
 shell waits for all commands in the pipeline to complete.
 
-Each command in a pipeline is executed in its own subshell
-(@pxref{Command Execution Environment}).  The exit
+Each command in a pipeline is executed in its own subshell, which is a
+separate process (@pxref{Command Execution Environment}).
+If the @code{lastpipe} option is enabled using the @code{shopt} builtin
+(@pxref{The Shopt Builtin}),
+the last element of a pipeline may be run by the shell process.
+
+The exit
 status of a pipeline is the exit status of the last command in the
 pipeline, unless the @code{pipefail} option is enabled
 (@pxref{The Set Builtin}).
@@ -714,7 +719,7 @@ An @sc{and} list has the form
 
 @noindent
 @var{command2} is executed if, and only if, @var{command1}
-returns an exit status of zero.
+returns an exit status of zero (success).
 
 An @sc{or} list has the form
 @example
@@ -739,7 +744,7 @@ executed in the list.
 * Command Grouping::		Ways to group commands.
 @end menu
 
-Compound commands are the shell programming constructs.
+Compound commands are the shell programming language constructs.
 Each construct begins with a reserved word or control operator and is
 terminated by a corresponding reserved word or operator.
 Any redirections (@pxref{Redirections}) associated with a compound command
@@ -798,12 +803,14 @@ The syntax of the @code{for} command is:
 for @var{name} [ [in [@var{words} @dots{}] ] ; ] do @var{commands}; done
 @end example
 
-Expand @var{words}, and execute @var{commands} once for each member
+Expand @var{words} (@pxref{Shell Expansions}), and execute @var{commands}
+once for each member
 in the resultant list, with @var{name} bound to the current member.
 If @samp{in @var{words}} is not present, the @code{for} command
 executes the @var{commands} once for each positional parameter that is
 set, as if @samp{in "$@@"} had been specified
 (@pxref{Special Parameters}).
+
 The return status is the exit status of the last command that executes.
 If there are no items in the expansion of @var{words}, no commands are
 executed, and the return status is zero.
@@ -874,6 +881,8 @@ case @var{word} in [ [(] @var{pattern} [| @var{pattern}]@dots{}) @var{command-li
 
 @code{case} will selectively execute the @var{command-list} corresponding to
 the first @var{pattern} that matches @var{word}.
+The match is performed according
+to the rules described below in @ref{Pattern Matching}.
 If the @code{nocasematch} shell option
 (see the description of @code{shopt} in @ref{The Shopt Builtin})
 is enabled, the match is performed without regard to the case
@@ -885,7 +894,9 @@ as a @var{clause}.
 
 Each clause must be terminated with @samp{;;}, @samp{;&}, or @samp{;;&}.
 The @var{word} undergoes tilde expansion, parameter expansion, command
-substitution, arithmetic expansion, and quote removal before matching is
+substitution, arithmetic expansion, and quote removal
+(@pxref{Shell Parameter Expansion})
+before matching is
 attempted.  Each @var{pattern} undergoes tilde expansion, parameter
 expansion, command substitution, and arithmetic expansion.
 
@@ -1045,7 +1056,7 @@ if there is a sequence of characters in the value consisting of
 any number, including zero, of 
 space characters, zero or one instances of @samp{a}, then a @samp{b}:
 @example
-[[ $line =~ [[:space:]]*(a)?b ]]
+[[ $line =~ [[:space:]]*?(a)b ]]
 @end example
 
 @noindent
@@ -1061,7 +1072,7 @@ expressions while paying attention to the shell's quote removal.
 Using a shell variable to store the pattern decreases these problems.
 For example, the following is equivalent to the above:
 @example
-pattern='[[:space:]]*(a)?b'
+pattern='[[:space:]]*?(a)b'
 [[ $line =~ $pattern ]]
 @end example