-------------------------------------
CHANGES FROM PREVIOUS VERSIONS OF ZSH
-------------------------------------

New features in zsh version 3.1.6 (beta version)
------------------------------------------------

New completion system via shell functions; massive degree of
programmability and configurability:
 - ready-made function suite to use, see zshcompsys(1)
 - approximate completion and spelling correction via completion
 - control over matching for case-independence, partial word completion, etc.
 - menu selection:  choose a completion by moving the cursor
 - coloured completion lists

Other editing changes:
  - enhancements to function/editing interface:  new parameters, numeric
    arguments, string argument passing, reading keys from widgets.
  - the old history-search-{back,for}ward behaviour and bindings have
    returned (up to minor details).
  - BASH_AUTO_LIST option to show completion list only on second key press.
  - the ZBEEP parameter gives a string to output instead of beeping,
    allowing you to have a visual bell.

History changes: new options HIST_NO_FUNCTIONS, HIST_EXPIRE_DUPS_FIRST,
HIST_FIND_NO_DUPS, HIST_IGNORE_ALL_DUPS, INC_APPEND_HISTORY,
HIST_SAVE_NO_DUPS, SHARE_HISTORY, allow better control of when history is
read and written and how duplicates are handled.

Associative arrays plus enhanced parameter substitutions to retrieve keys
and values.

Globbing changes:
  - Case-insensitive and approximate globbing.
  - Ordering and indexing of globbing matches, e.g. *(om[1]) picks
    most recently modified file.

New loadable modules:
  - zftp, plus associated function suite, for turning your zsh session
    into an FTP session too
  - parameter, for examining and altering shell hash tables via an
    associative array interface.
  - mapfile, for reading and writing external files via an associative
    array interface.

Debugging and prompt enhancements:
  - LINENO is now very much more useful in scripts and functions and has
    corresponding prompt escape %i
  - $PS4 can contain %i as well as %N for script or function names
    (default PS4 changed), also %_ for current shell structure executing; 
  - Prompt truncation %<...< is now more flexible: it applies to a
    whole section of the prompt, not just one escape.  You need to put
    %<< after the truncated escape to get the old behaviour.
  - %20(l.yes.no) in prompts prints yes if at least 20 characters have
    been output, else no (e.g. for outputting extra newlines).

Parameter and expansion changes
  - typeset -t MYPATH mypath creates tied path/PATH-like variables
  - typeset -g allows operations on parameters without making them local
  - New expansions
    - ${(t)param} prints type information for $param
    - ${(P)param} treats value of $param as the name of a param to
      substitute
    - ${foo:q} can quote replaced parameter text from expansion
    - ${foo/old/new} substitution, like bash; also (S) flag for shortest
      match
    - $foo[(b.2.i)bar] starts searching $foo for bar starting at 2nd match
    - more logical behaviour of nested parameters, now properly documented
    - quote only nested expansion, e.g. ${(f)"$(<file)"} reads complete
      `file', then splits lines into array.

Builtin and function changes
  - stat module: `stat -H hash foo' gives you e.g. $hash[mtime]
  - autoload -U autoloads functions without alias expansion.

Other new options:
  - LOCAL_TRAPS allows signal traps to be local to functions (as in ksh).
  - NO_RCS can now be turned on at any point in initialization files.
  - NO_GLOBAL_RCS can force /etc/z* files after /etc/zshenv to be skipped.
    (Please don't use this as an excuse to stuff more into /etc/zshenv!)
  - existing MAGIC_EQUAL_SUBST option is more useful; any argument containing
    ...=~...:~... will perform filename expansion on the ~.

Configuration changes:
  - Large file and 64-bit integers on 32-bit machines supported where
    provided by OS.
  - generation of signal names should be more reliable
  - Customizable installation of shell functions from distribution.


New features in zsh version 3.1 (beta version)
----------------------------------------------

On most operating systems zsh can load binary modules dynamically at
run-time.  ZLE and the compctl builtin are now reside in a separate
module which is loaded automatically on demand.

for ((expr; expr; expr)) do ... done loop syntax from AT&T ksh93 is
now supported.

POSIX globbing character classes ([:alnum:] etc.) are now supported.

ksh's case fall-through feature (;&) is supported.

ksh93's $'' quoting syntax is supported.

Restricted mode is now supported.  This is controlled by the new option
RESTRICTED (-r).

New options BARE_GLOB_QUAL, HIST_NO_FUNCTIONS (alias NO_LOG), KSH_GLOB,
PRINT_EIGHT_BIT, PROMPT_BANG, PROMPT_PERCENT, RM_STAR_WAIT.

Options ALWAYS_LAST_PROMPT, APPEND_HISTORY, AUTO_LIST, AUTO_MENU,
AUTO_PARAM_KEYS, AUTO_PARAM_SLASH, AUTO_REMOVE_SLASH, LIST_AMBIGUOUS
and LIST_TYPES are now on by default.

In ZLE, arbitrarily many keymaps can be defined.  Multi-character
keybindings now work.

Completion can be performed within a brace expansion.

EMACS-like universal-argument function.


New features in zsh version 3.0
-------------------------------

Trailing "/" in a glob pattern now works like in other shell thus it
can no longer be used as a sorthand for "(/)".

Much improved sh/ksh emulation.  When zsh is invoked as sh it mostly
conforms to POSIX 1003.2.

Enhanced parameter expansion features: new flags: A, @, e, W, p, f, F.
Expansions can be nested.  For example,
"${${(M)${(f@)$(<builtin.pro)}:#char*}[2][(w)3]}" expands to the third
word of the second line of builtin.pro which begins with char.  See
zshexpn(1) for the details.

***/foo glob does recursive directory search following symbolic links.

Traps defined by the trap builtin are now executed in the current shell
environment and not as a shell function.  This means that $1 is not set
to the signal number.  Of course the TRAPxxx functions continue working
as before.

Traps defined by the trap builtin are reset to their default values in
subshells.

Option names can be prefixed by `no' to unset an option.
setopt no_option_name is the same as unsetopt option_name.
This change affects the output of the setopt and unsetopt
builtins when these are invoked without arguments.  See
the zshoptions manual page for more explanation.

!, {, } and [[ are now reserved words.  Things like [[-z $foo]] or {foo}
should not be used.  {foo} still works if the IGNORE_BRACES option is not
set but this feature may be removed in the future.  [[ -z $foo ]] and
{ foo } should be used instead.

HOSTTYPE special parameter is removed.  The new OSTYPE, MACHTYPE and
VENDOR parameters should be used instead.

VERSION parameter is renamed to ZSH_VERSION

exec now saves the history in interactive shells.  If you do not like this
behaviour you can alias exec to 'unset HISTFILE ; exec'.

${~spec}, ${=spec} and ${^spec} used to toggle the effect of
globsubst/shwordsplit/rcexpandparam.  Now these force the corresponding
option on. ~, = or ^ can be doubled to force the relevant option off for
the substitution.

Explicitly requested word splitting like ${=spec} or ${(s:delim:)spec}
will be executed even if the substitution is double quoted.

The right-hand side of assignments are no longer globbed by default hence
assignment foo=* will assign '*' as a value of foo.  Use the foo=( * )
array assignment syntax to get the old behaviour.  Alternatively the
GLOB_ASSIGN can be set to emulate the old behaviour but the usage of this
option is strongly discouraged and this option may be completely removed in
the future.

foo=$bar no longer creates an array even if bar is an array.  Use
foo=( $bar ) or even better, foo=( "$bar[@]" ) instead.

When foo is an array parameter ${#foo} will always return the length of the
array even if the substitution is double quoted.  ${(c)#foo} should be used
to get back the old behaviour.

When the prompt_subst option is set prompts are fully expanded using
parameter expansion, command substitution and arithmetic expansion.
In 2.5 backquote substitution was not performed in the prompts so this
change might cause problems in some startup scripts if ` is used literally
in prompts.

History substitution is now not performed if the history escape character
appears in a single-quoted string.  This may break some interactive shell
functions which use \! in single-quoted strings.

The UID, EUID, GID, EGID parameters can be assigned now. The assignment
executes the setuid(), seteuid(), setgid(), setegid() respectively.  On
systems where setuid and seteuid is not supported these functions are
emulated using setreuid or setresuid which may result in a different
behaviour.

Assigning the USERNAME parameter will call setuid(uid) where uid is the
user id of the specified user.

The privileged (-p) option is automatically set on invocation if euid != uid
or egid != gid.  If this option is set no user startup files are sourced.
The shell will drop privileges when this option is unset by resetting its
euid to uid and its egid to gid.

The =number substitution for accessing the directory stack is changed to
~number to allow =command substitution when a command name begins with a 
digit.

<> is a redirection operator which opens the standard input for both
reading and writing.  To match a number use <->.

Option letters -1 and -C for PRINT_EXIT_VALUE and NO_CLOBBER are swapped:
`set -C' sets NO_CLOBBER and `set -1' sets PRINT_EXIT_VALUE.

AUTO_PUSHD behaviour is changed.  Now cd without arguments will always go
to the $HOME directory even if AUTO_PUSHD is set and PUSHD_TO_HOME is not
set.  If you preferred the old behaviour you can alias cd to pushd.

IFS word splitting with SH_WORD_SPLIT and the splitting of the input in the
read builtin has changed in cases when IFS contains characters other than
<space>, <tab>, <newline>.  See the description of IFS in the zshparam
manual page for more details.


New features in zsh version 2.5
-------------------------------

Greatly expanded completion possibilities.  Programmable completion
allows detailed control over what arguments of what commands can be
completed to what.  See dots/zcomp in the distribution for examples.

Expand filenames with ~ and = on the right hand side of parameter
assignments.  New option MAGIC_EQUAL_SUBST to do it in all
identifier=expression arguments.

${+name} becomes 1 or 0 if name is set or unset.  ${~spec} toggles
GLOB_SUBST in substitution.  Parameter substitution takes lots
of flags in the format ${(flags)name}.

New glob qualifiers for block/character special files, times in glob
qualifiers can be in months, weeks, days, hours, minutes.  Qualifiers can
work on links or on what they point to.  Qualifiers separated by commas
are or-ed.

New parameter substitution modifiers (fFwW) to repeat actions.  New
option CSH_JUNKIE_HISTORY.

New line editor functions history-beginning-search-backward,
history-beginning-search-forward, expand-or-complete-prefix, push-input,
push-line-or-edit.

Assign to part of a string, use qualifiers on string subscription with
$foo[(qual)2,5]

New parameters: EGID, EUID, KEYTIMEOUT

New prompt escape sequence %_ to get constructs like for and while in
the secondary prompt.  %E in prompt clears to end of screen.

Conditional expressions in PROMPT and WATCHFMT.

New options ALWAYS_LAST_PROMPT, ALWAYS_TO_END, AUTO_PARAM_KEYS,
COMPLETE_ALIASES, COMPLETE_IN_WORD, CSH_JUNKIE_HISTORY, GLOB_SUBST,
LIST_AMBIGUOUS, MAGIC_EQUAL_SUBST, NO_FLOW_CONTROL, PROMPT_SUBST

New option -m to many builtins makes arguments subject to pattern
matching.

Bindkey can now bind both key sequences and prefixes of those.  You can
for example bind ESC and function keys sending ESC sequences.

Additional options to read builtin to use in functions called by
completion.

New options to print to sort arguments and print them in columns.

Some additional resource limits can be specified.

Some editor functions now work in the minibuffer.