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bash-5.0-beta2 release
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@@ -1,9 +1,9 @@
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<!-- This text is a brief description of the features that are present in
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the Bash shell (version 5.0, 7 August 2018).
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the Bash shell (version 5.0, 9 November 2018).
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This is Edition 5.0, last updated 7 August 2018,
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This is Edition 5.0, last updated 9 November 2018,
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of The GNU Bash Reference Manual,
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for Bash, Version 5.0.
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@@ -284,10 +284,10 @@ Next: <a href="#Introduction" accesskey="n" rel="next">Introduction</a>, Previou
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<h1 class="top">Bash Features</h1>
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<p>This text is a brief description of the features that are present in
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the Bash shell (version 5.0, 7 August 2018).
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the Bash shell (version 5.0, 9 November 2018).
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The Bash home page is <a href="http://www.gnu.org/software/bash/">http://www.gnu.org/software/bash/</a>.
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</p>
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<p>This is Edition 5.0, last updated 7 August 2018,
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<p>This is Edition 5.0, last updated 9 November 2018,
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of <cite>The GNU Bash Reference Manual</cite>,
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for <code>Bash</code>, Version 5.0.
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</p>
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@@ -2222,8 +2222,8 @@ to the filename used to invoke Bash, as given by argument zero.
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At shell startup, set to the absolute pathname used to invoke the
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shell or shell script being executed as passed in the environment
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or argument list.
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Subsequently, expands to the last argument to the previous command,
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after expansion.
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Subsequently, expands to the last argument to the previous simple
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command executed in the foreground, after expansion.
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Also set to the full pathname used to invoke each command executed
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and placed in the environment exported to that command.
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When checking mail, this parameter holds the name of the mail file.
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@@ -4455,19 +4455,22 @@ false.
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</dd>
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<dt>3 arguments</dt>
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<dd><p>The following conditions are applied in the order listed.
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If the second argument is one of the binary conditional
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</p>
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<ol>
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<li> If the second argument is one of the binary conditional
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operators (see <a href="#Bash-Conditional-Expressions">Bash Conditional Expressions</a>), the
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result of the expression is the result of the binary test using the
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first and third arguments as operands.
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The ‘<samp>-a</samp>’ and ‘<samp>-o</samp>’ operators are considered binary operators
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when there are three arguments.
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If the first argument is ‘<samp>!</samp>’, the value is the negation of
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</li><li> If the first argument is ‘<samp>!</samp>’, the value is the negation of
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the two-argument test using the second and third arguments.
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If the first argument is exactly ‘<samp>(</samp>’ and the third argument is
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</li><li> If the first argument is exactly ‘<samp>(</samp>’ and the third argument is
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exactly ‘<samp>)</samp>’, the result is the one-argument test of the second
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argument.
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Otherwise, the expression is false.
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</p>
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</li><li> Otherwise, the expression is false.
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</li></ol>
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</dd>
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<dt>4 arguments</dt>
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<dd><p>If the first argument is ‘<samp>!</samp>’, the result is the negation of
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@@ -5300,7 +5303,7 @@ The prompt is displayed only if input is coming from a terminal.
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<dt><code>-r</code></dt>
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<dd><p>If this option is given, backslash does not act as an escape character.
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The backslash is considered to be part of the line.
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In particular, a backslash-newline pair may not be used as a line
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In particular, a backslash-newline pair may not then be used as a line
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continuation.
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</p>
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</dd>
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@@ -6024,6 +6027,7 @@ The shell always postpones exiting if any jobs are stopped.
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<dd><p>If set, Bash checks the window size after each external (non-builtin)
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command and, if necessary, updates the values of
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<code>LINES</code> and <code>COLUMNS</code>.
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This option is enabled by default.
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</p>
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</dd>
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<dt><code>cmdhist</code></dt>
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@@ -6289,6 +6293,13 @@ the same name that exists at a previous scope before any new value is
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assigned. The <var>nameref</var> attribute is not inherited.
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</p>
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</dd>
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<dt><code>localvar_unset</code></dt>
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<dd><p>If set, calling <code>unset</code> on local variables in previous function scopes
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marks them so subsequent lookups find them unset until that function
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returns. This is identical to the behavior of unsetting local variables
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at the current function scope.
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</p>
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</dd>
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<dt><code>login_shell</code></dt>
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<dd><p>The shell sets this option if it is started as a login shell
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(see <a href="#Invoking-Bash">Invoking Bash</a>).
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@@ -6331,6 +6342,13 @@ files to expand to a null string, rather than themselves.
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This option is enabled by default.
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</p>
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</dd>
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<dt><code>progcomp_alias</code></dt>
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<dd><p>If set, and programmable completion is enabled, Bash treats a command
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name that doesn’t have any completions as a possible alias and attempts
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alias expansion. If it has an alias, Bash attempts programmable
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completion using the command word resulting from the expanded alias.
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</p>
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</dd>
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<dt><code>promptvars</code></dt>
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<dd><p>If set, prompt strings undergo
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parameter expansion, command substitution, arithmetic
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@@ -8108,9 +8126,13 @@ Next: <a href="#Shell-Arithmetic" accesskey="n" rel="next">Shell Arithmetic</a>,
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<a name="index-expressions_002c-conditional"></a>
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<p>Conditional expressions are used by the <code>[[</code> compound command
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and the <code>test</code> and <code>[</code> builtin commands.
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and the <code>test</code> and <code>[</code> builtin commands. The <code>test</code>
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and <code>[</code> commands determine their behavior based on the number
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of arguments; see the descriptions of those commands for any other
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command-specific actions.
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</p>
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<p>Expressions may be unary or binary.
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<p>Expressions may be unary or binary,
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and are formed from the following primaries.
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Unary expressions are often used to examine the status of a file.
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There are string operators and numeric comparison operators as well.
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Bash handles several filenames specially when they are used in
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@@ -8464,10 +8486,11 @@ unless the <code>expand_aliases</code> shell option is set using
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<code>shopt</code> (see <a href="#The-Shopt-Builtin">The Shopt Builtin</a>).
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</p>
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<p>The rules concerning the definition and use of aliases are
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somewhat confusing. Bash
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always reads at least one complete line
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of input before executing any
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of the commands on that line. Aliases are expanded when a
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somewhat confusing. Bash
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always reads at least one complete line of input,
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and all lines that make up a compound command,
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before executing any of the commands on that line or the compound command.
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Aliases are expanded when a
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command is read, not when it is executed. Therefore, an
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alias definition appearing on the same line as another
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command does not take effect until the next line of input is read.
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@@ -9113,6 +9136,11 @@ the <samp>-e</samp> option from the parent shell.
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When the <code>inherit_errexit</code> option is not enabled,
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Bash clears the <samp>-e</samp> option in such subshells.
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</li><li> Enabling <small>POSIX</small> mode has the effect of setting the
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<code>shift_verbose</code> option, so numeric arguments to <code>shift</code>
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that exceed the number of positional parameters will result in an
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error message.
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</li><li> When the <code>alias</code> builtin displays alias definitions, it does not
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display them with a leading ‘<samp>alias </samp>’ unless the <samp>-p</samp> option
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is supplied.
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@@ -9129,6 +9157,12 @@ constructed from <code>$PWD</code> and the directory name supplied as an argumen
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does not refer to an existing directory, <code>cd</code> will fail instead of
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falling back to <var>physical</var> mode.
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</li><li> When the <code>cd</code> builtin cannot change a directory because the
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length of the pathname
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constructed from <code>$PWD</code> and the directory name supplied as an argument
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exceeds <var>PATH_MAX</var> when all symbolic links are expanded, <code>cd</code> will
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fail instead of attempting to use only the supplied directory name.
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</li><li> The <code>pwd</code> builtin verifies that the value it prints is the same as the
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current directory, even if it is not asked to check the file system with the
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<samp>-P</samp> option.
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@@ -10195,7 +10229,7 @@ If this variable has not been given a value, the characters <tt class="key">ESC<
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<dt><code>keymap</code></dt>
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<dd><a name="index-keymap"></a>
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<p>Sets Readline’s idea of the current keymap for key binding commands.
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Acceptable <code>keymap</code> names are
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Built-in <code>keymap</code> names are
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<code>emacs</code>,
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<code>emacs-standard</code>,
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<code>emacs-meta</code>,
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@@ -10206,6 +10240,7 @@ Acceptable <code>keymap</code> names are
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<code>vi-insert</code>.
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<code>vi</code> is equivalent to <code>vi-command</code> (<code>vi-move</code> is also a
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synonym); <code>emacs</code> is equivalent to <code>emacs-standard</code>.
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Applications may add additional names.
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The default value is <code>emacs</code>.
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The value of the <code>editing-mode</code> variable also affects the
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default keymap.
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@@ -11840,6 +11875,9 @@ If no compspec is found for the full pathname, an attempt is made to
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find a compspec for the portion following the final slash.
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If those searches do not result in a compspec, any compspec defined with
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the <samp>-D</samp> option to <code>complete</code> is used as the default.
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If there is no default compspec, Bash attempts alias expansion
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on the command word as a final resort, and attempts to find a compspec
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for the command word from any successful expansion
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</p>
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<p>Once a compspec has been found, it is used to generate the list of
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matching words.
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