Z-Shell (zsh) FAQ changes this month

[Peter Stephenson <pws@xxxxxxxxxxxxxxxxx>]

This file contains general information on how to find out about zsh,
(the first part of the FAQ up to item 1.1), then any other items which
have changed since last month's posting, then the differences in the
yodl version of the FAQ.  If you would like a complete individual
copy, email me and I will add you to the list.


Changes since issue posted June 1999:

1.6  FTP site changes
3.9  delete bogus claim that ttyctl code may be updated some day;
     add note about possible termcap deinitialization sequences
5.1  80-column display bug.

This document contains a list of frequently-asked (or otherwise
significant) questions concerning the Z-shell, a command interpreter
for many UNIX systems which is freely available to anyone with FTP
access.  Zsh is among the most powerful freely available Bourne-like
shell for interactive use.

If you have never heard of `sh', `csh' or `ksh', then you are
probably better off to start by reading a general introduction to UNIX
rather than this document.

If you just want to know how to get your hands on the latest version,
skip to question 1.6; if you want to know what to do with
insoluble problems, go to 5.2.

Notation: Quotes `like this' are ordinary textual quotation
marks.  Other uses of quotation marks are input to the shell.

Contents:
Chapter 1:  Introducing zsh and how to install it
1.1. Sources of information
1.2. What is it?
1.3. What is it good at?
1.4. On what machines will it run?  (Plus important compilation notes)
1.5. What's the latest version?
1.6. Where do I get it?
1.7. I don't have root access: how do I make zsh my login shell?

Chapter 2:  How does zsh differ from...?
2.1. sh and ksh?
2.2. csh?
2.3. Why do my csh aliases not work?  (Plus other alias pitfalls.)
2.4. tcsh?
2.5. bash?
2.6. Shouldn't zsh be more/less like ksh/(t)csh?

Chapter 3:  How to get various things to work
3.1. Why does `$var' where `var="foo bar"' not do what I expect?
3.2. In which startup file do I put...?
3.3. What is the difference between `export' and the ALL_EXPORT option?
3.4. How do I turn off spelling correction/globbing for a single command?
3.5. How do I get the meta key to work on my xterm?
3.6. How do I automatically display the directory in my xterm title bar?
3.7. How do I make the completion list use eight bit characters?
3.8. Why do the cursor (arrow) keys not work?
3.9. Why does my terminal act funny in some way?
3.10. Why does zsh not work in an Emacs shell mode any more?
3.11. Why do my autoloaded functions not autoload [the first time]?
3.12. How does base arithmetic work?
3.13. How do I get a newline in my prompt?
3.14. Why does `bindkey ^a command-name' or 'stty intr ^-' do something funny?
3.15. Why can't I bind \C-s and \C-q any more?
3.16. How do I execute command `foo' within function `foo'?
3.17. Why do history substitutions with single bangs do something funny?
3.18. Why does zsh kill off all my background jobs when I logout?
3.19. How do I list all my history entries?
3.20. How does the alternative loop syntax, e.g. `while {...} {...}' work?
3.21. Why is my history not being saved?
3.22. How do I get a variable's value to be evaluated as another variable?
3.23. How do I prevent the prompt overwriting output when there is no newline?
3.24. What's wrong with cut and paste on my xterm?

Chapter 4:  The mysteries of completion
4.1. What is completion?
4.2. What sorts of things can be completed?
4.3. How does zsh deal with ambiguous completions?
4.4. How do I complete in the middle of words / just what's before the cursor?
4.5. How do I get started with programmable completion?
4.6. And if programmable completion isn't good enough?

Chapter 5:  The future of zsh
5.1. What bugs are currently known and unfixed? (Plus recent important changes)
5.2. Where do I report bugs, get more info / who's working on zsh?
5.3. What's on the wish-list?
5.4. Will zsh have problems in the year 2000?

Acknowledgments

Copyright
--- End of Contents ---

Chapter 1: Introducing zsh and how to install it

1.1: Sources of information

  Information on zsh is available via the World Wide Web.  The URL
  is http://sunsite.auc.dk/zsh/ (note the change of address from the
  end of April 1998).  The server provides this FAQ and much else and is
  now maintained by Karsten Thygesen and others (mail zsh@xxxxxxxxxxxxxx
  with any related messages).  The FAQ is at http://sunsite.auc.dk/zsh/FAQ/ .
  The site also contains some contributed zsh scripts and functions;
  we are delighted to add more, or simply links to your own collection.

  This document was originally written in YODL, allowing it to be converted
  easily into various other formats.  The master source file lives at
  http://sunsite.auc.dk/zsh/FAQ/zshfaq.yo and the plain text version
  can be found at http://sunsite.auc.dk/zsh/FAQ/zshfaq.txt .

  Another useful source of information is the collection of FAQ articles
  posted frequently to the Usenet news groups comp.unix.questions,
  comp.unix.shells and comp.answers with answers to general questions
  about UNIX.  The fifth of the seven articles deals with shells,
  including zsh, with a brief description of differences.  There is
  also a separate FAQ on shell differences and how to change your
  shell.  Usenet FAQs are available via FTP from rtfm.mit.edu and
  mirrors and also on the World Wide Web; see

    USA         http://www.cis.ohio-state.edu/hypertext/faq/usenet/top.html
    UK          http://www.lib.ox.ac.uk/internet/news/faq/comp.unix.shell.html
    Netherlands http://www.cs.uu.nl/wais/html/na-dir/unix-faq/shell/.html

  You can also get it via email by emailing mail-server@xxxxxxxxxxxx
  with, in the body of the message, `send faqs/unix-faq/shell/zsh'.

  The latest version of this FAQ is also available directly from any
  of the zsh archive sites listed in question 1.6.

  There is now a preliminary version of a reference card for
  zsh 3.0, which you can find (while it's being developed) at
    http://www.ifh.de/~pws/computing/refcard.ps
  This is optimised for A4 paper. The LaTeX source is in the
  same place with the extension .tex.  It is not a good place
  from which to learn zsh for the first time.

  (As a method of reading the following in Emacs, you can type \M-2
  \C-x $ to make all the indented text vanish, then \M-0 \C-x $
  when you are on the title you want.)

  For any more eclectic information, you should contact the mailing
  list:  see question 5.2.

--- End of general information, changed items follow in full ---

1.6: Where do I get it?

  The coordinator of development is currently me; the alias
  coordinator@xxxxxxx can be used to contact whoever is in the hot
  seat.  The following are known mirrors (kept frequently up to date); the
  first is the official archive site, currently in Australia.  All are
  available by anonymous FTP.  The major sites keep test versions in the
  `testing' subdirectory: such up-to-the-minute development versions should
  only be retrieved if you actually plan to help test the latest version of
  the shell.  The following list also appears on the WWW at
  http://www.zsh.org .

    Home site ftp://ftp.zsh.org
              http://www.zsh.org/pub/zsh/
    Australia ftp://ftp.ips.gov.au/mirror/zsh/
    Denmark   ftp://sunsite.auc.dk/pub/unix/shells/zsh
    Finland   ftp://ftp.funet.fi/pub/unix/shells/zsh/
    France    ftp://ftp.cenatls.cena.dgac.fr/pub/shells/zsh/
    Germany   ftp://ftp.fu-berlin.de/pub/unix/shells/zsh/
              ftp://ftp.gmd.de/packages/zsh/
              ftp://ftp.uni-trier.de/pub/unix/shell/zsh/
    Hungary   ftp://ftp.cs.elte.hu/pub/zsh/
              (also http://www.cs.elte.hu/pub/zsh/ )
              ftp://ftp.kfki.hu/pub/packages/zsh/
    Israel    ftp://ftp.math.technion.ac.il/mirror/ftp.zsh.org/pub/zsh/
              http://www.math.technion.ac.il/mirror/ftp.zsh.org/pub/zsh/
    Italy     ftp://ftp.unina.it/pub/Unix/pkgs/shell/zsh/
    Japan     ftp://ftp.tohoku.ac.jp/mirror/zsh/
              ftp://ftp.nisiq.net/pub/shells/zsh/
              ftp://ftp.win.ne.jp/pub/shell/zsh/
    Norway    ftp://ftp.uit.no/pub/unix/shells/zsh/
    Romania   ftp://ftp.roedu.net/pub/mirrors/ftp.zsh.org/pub/zsh/
    Slovenia  ftp://ftp.siol.net/pub/unix/shells/zsh/
    Sweden    ftp://ftp.lysator.liu.se/pub/unix/zsh/
    UK        ftp://ftp.net.lut.ac.uk/zsh/
              (also by FSP at port 21)
              ftp://sunsite.org.uk/packages/zsh/
    USA       ftp://ftp.math.gatech.edu/pub/zsh/
              ftp://uiarchive.uiuc.edu/pub/packages/shells/zsh/
              ftp://ftp.rge.com/pub/shells/zsh/
              ftp://foad.org/pub/zsh/
              http://foad.org/zsh/

  The Windows port mentioned above is maintained separately by Amol
  Deshpande <amold@xxxxxxxxxxxxx>; please mail Amol directly about any
  Windows-specific problems.  This is quite new, so don't expect it to
  be perfect.  You can get it from:

            ftp://ftp.blarg.net/users/amol/zsh  

  Likewise the OS/2 port is available from TAMURA Kent
  <kent@xxxxxxxxxxxxxx> at

            http://cgi.din.or.jp/~tkent/tmp/zsh-3.0.0-os2-a01.zip

  Starting from mid-October 1997, there is an archive of patches sent
  to the maintainers' mailing list.  Note that these may not all be
  added to the shell, and some may already have been; you simply have
  to search for something you might want which is not in the version
  you have.  Also, there may be some prerequisites earlier in the
  archive.  It can be found on the zsh WWW pages (as described in
  1.1) at:

            http://sunsite.auc.dk/zsh/Patches/

3.9: Why does my terminal act funny in some way?

  If you are using an OpenWindows cmdtool as your terminal, any
  escape sequences (such as those produced by cursor keys) will be
  swallowed up and never reach zsh.  Either use shelltool or avoid
  commands with escape sequences.  You can also disable scrolling from
  the cmdtool pane menu (which effectively turns it into a shelltool).
  If you still want scrolling, try using an xterm with the scrollbar
  activated.

  If that's not the problem, and you are using stty to change some tty
  settings, make sure you haven't asked zsh to freeze the tty settings:
  type

    ttyctl -u

  before any stty commands you use.

  On the other hand, if you aren't using stty and have problems you may
  need the opposite:  `ttyctl -f' freezes the terminal to protect it
  from hiccups introduced by other programmes (kermit has been known to
  do this).

  A problem I have experienced myself (on an AIX 3.2 workstation with
  xterm) is that termcap deinitialization sequences sent by `less'
  were causing automargins to be turned off --- not actually a shell
  problem, but you might have thought it was.  The fix is to put `X'
  into the environment variable LESS to stop the sequences being sent.
  Other programs (though not zsh) may also send that sequence.

  If _that_'s not the problem, and you are having difficulties with
  external commands (not part of zsh), and you think some terminal
  setting is wrong (e.g. ^V is getting interpreted as `literal next
  character' when you don't want it to be), try

    ttyctl -u
    STTY='lnext "^-"' commandname

  (in this example), or just export STTY for all commands to see.  Note
  that zsh doesn't reset the terminal completely afterwards: just the
  modes it uses itself and a number of special processing characters
  (see the stty(1) manual page).

5.1: What bugs are currently known and unfixed? (Plus recent important changes)

  Here are some of the more well-known ones, very roughly in
  decreasing order of significance.  Many of these can also be counted
  against differences from ksh in question 2.1; note that this applies
  to the latest beta version and that simple bugs are often fixed
  quite quickly.  There is a file Etc/BUGS in the source distribution
  with more detail.

  o  `time' is ignored with builtins and can't be used with `{...}'.
  o  When showing completion lists with exactly 80 columns, some
       terminals print an extra newline which messes up zsh's logic.  
  o  `set -x' (`setopt xtrace') still has a few glitches; these
     are mostly fixed in 3.1.6.
  o  Zsh's notion of the current line number (via $LINENO) is
     sometimes not well handled, particularly when using functions and traps.
     This should also work reliably from 3.1.6.
  o  In vi mode, `u' can go past the original modification point.
  o  The singlelinezle option has problems with prompts containing escapes.
  o  The `r' command does not work inside `$(...)' or ``...`'
     expansions.   This is fixed in 3.1.
  o  `typeset' handling is non-optimal, particularly with regard to
     flags, and is ksh-incompatible in unpredictable ways.  3.1.6 has
     been overhauled, but remaining glitches are to be expected.
  o  Nested closures in extended globbing and pattern matching, such as

      [[ fofo = (fo#)# ]]

     were not correctly handled, and there were problems with
     complicated exclusions using `^' or `~'.  These
     are fixed in version 3.1.3.

  Note that a few recent changes introduce incompatibilities (these
  are not bugs):

  Changes after zsh 3.0 (3.1.x is still currently in beta):

  o  The options ALWAYS_LAST_PROMPT (return to the line you were
     editing after displaying completion lists) and LIST_AMBIGUOUS
     (don't do AUTO_LIST if there was an unambiguous prefix that could be
     inserted, i.e. only list if it is ambiguous what to insert next) are
     now set by default.  This is in response to complaints that too many
     zsh features are never noticed by many users.  To turn them off,
     just put `unsetopt alwayslastprompt listambiguous' in your
     .zshrc file.
  o  In 3.1.5, history-search-{forward,backward} only find previous
     lines where the first word is the same as the current one.  For
     example, 

      comp<ESC>p

     will find lines in the history like `comp -edit emacs', but not
     `compress file' any more.  For this reason, `\M-n' and
     `\M-p' use history-beginning-search-{forward,backward} which
     search for a line with the same prefix up to the cursor position.
     From 3.1.6, there will be a different implementation which
     makes this closer (though not identical) to the old behaviour.
     The story for the {up,down}-line-or-search commands is similar.
  o  In vi insert mode, the cursor keys no longer work.  The following
     will bind them:

       bindkey -M viins '^[[D' vi-backward-char '^[[C' vi-forward-char \ 
                      '^[[A' up-line-or-history '^[[B' down-line-or-history

     (unless your terminal requires `^[O' instead of `^[[').  The
     rationale is that the insert mode and command mode keymaps for
     keys with prefixes are now separate.

  Changes since zsh 2.5:

  o  The left hand of an assignment is no longer substituted.  Thus,
     `$1=$2' will not work.  You can use something like `eval
     "$1=\$2"', which should have the identical effect.
  o  Signal traps established with the `trap' builtin are now called with
     the environment of the caller, as in ksh, instead of as a new
     function level.  Traps established as functions (e.g. `TRAPINT()
     {...}') work as before.
  o  The NO_CLOBBER option is now -C and PRINT_EXIT_VALUE -1; they
     used to be the other way around.  (Use of names rather than letters is
     generally recommended.)
  o  `[[' is a reserved word, hence must be separated from
     other characters by whitespace; `{' and `}' are also reserved
     words if the IGNORE_BRACES option is set.
  o  The option CSH_JUNKIE_PAREN has been removed:  csh-like code now
     always does what it looks like it does, so `if ( ... ) ...'
     executes the code in parentheses in a subshell.  To make this
     useful, the syntax expected after an `if', etc., is less strict
     than in other shells.
  o  `foo=*' does not perform globbing immediately on the right
     hand side of the assignment; the old behaviour now requires the
     option GLOB_ASSIGN.  (`foo=(*)' is and has always been the
     consistent way of doing this.)
  o  <> performs redirection of input and output to the specified file.
     For numeric globs, you now need <->.
  o  The command line qualifiers exec, noglob, command, - are now
     treated more like builtin commands:  previously they were
     syntactically special.  This should make it easier to perform
     tricks with them (disabling, hiding in parameters, etc.).
  o  The pushd builtin has been rewritten for compatibility with other
     shells.  The old behavour can be achieved with a shell function.
  o  The current version now uses ~'s for directory stack substitution
     instead of ='s.  This is for consistency:  all other directory
     substitution (~user, ~name, ~+, ...) used a tilde, while
     =<number> caused problems with =program substitution.
  o  The HISTLIT option was broken in various ways and has been removed:
     the rewritten history mechanism doesn't alter history lines, making
     the option unnecessary.
  o  History expansion is disabled in single-quoted strings, like other
     forms of expansion -- hence exclamation marks there should not be
     backslashed.
  o  The `$HISTCHARS' variable is now `$histchars'.  Currently both
     are tied together for compatibility.
  o  The PROMPT_SUBST option now performs backquote expansion -- hence
     you should quote these in prompts.  (SPROMPT has changed as a result.)
  o  Quoting in prompts has changed: close parentheses inside ternary
     expressions should be quoted with a %; history is now %!, not
     !.  Backslashes are no longer special.

--- End of changed items, diff from previous version follows ---
Index: zshfaq.yo
===================================================================
RCS file: /pack/anoncvs/zsh/www/FAQ/zshfaq.yo,v
retrieving revision 1.43
retrieving revision 1.44
diff -u -r1.43 -r1.44
--- zshfaq.yo	1999/06/24 12:57:34	1.43
+++ zshfaq.yo	1999/07/24 12:43:15	1.44
@@ -13,7 +13,7 @@
   whenhtml(bf(ARG1))\
   whenlatex(bf(ARG1))\
   whenms(bf(ARG1))\
-  whensgml(bf(ARG1)))
+  whensgml(bf(ARG1)))\
 def(myem)(1)(\
   whentxt(_ARG1_)\
   whenhtml(em(ARG1))\
@@ -45,28 +45,21 @@
 whensgml(report(ARG1)(ARG2)(ARG3)))
 myreport(Z-Shell Frequently-Asked Questions)(Peter Stephenson)(1999/05/24)
 COMMENT(-- the following are for Usenet and must appear first)\
-description(
+description(\
 mydit(Archive-Name:) unix-faq/shell/zsh
-mydit(Last-Modified:) 1999/05/24
+mydit(Last-Modified:) 1999/07/24
 mydit(Submitted-By:) email(pws@xxxxxxxxxxxxxxxxx (Peter Stephenson))
-mydit(Version:) $Id: zshfaq.yo,v 1.43 1999/06/24 12:57:34 pws Exp $
+mydit(Version:) $Id: zshfaq.yo,v 1.44 1999/07/24 12:43:15 pws Exp $
 mydit(Posting-Frequency:) Monthly
 mydit(Copyright:) (C) P.W. Stephenson, 1995--1999 (see end of document)
 )
 
-bf(Changes since issue posted May 1999:)
+bf(Changes since issue posted June 1999:)
 description(
-mydit(1.5)  3.1.6 may appear
-mydit(1.6)  updated list of archive sites; coordinator@xxxxxxx alias;
-     new coordinator, alas.
-mydit(2.1)  mention tt(SHARE_HISTORY); deleted item on
-     tt($(echo '\$x')) difference (can't find this any more); function
-     definitions aren't local to functions in ksh either, only traps.
-mydit(3.7)  tt(PRINT_EIGHT_BIT) will be in 3.0.6
-mydit(3.24) new: cut-and-paste problems
-mydit(5.1)  xtrace and LINENO will work better in 3.1.6
-mydit(5.2)  no mailing list archive at ftp.sterling.com
-mydit(5.3)  New completion command menu-select for 3.1.6
+mydit(1.6)  FTP site changes
+mydit(3.9)  delete bogus claim that ttyctl code may be updated some day;
+     add note about possible termcap deinitialization sequences
+mydit(5.1)  80-column display bug.
 )
 
 This document contains a list of frequently-asked (or otherwise
@@ -371,6 +364,8 @@
     mydit()          \
 url(http://www.math.technion.ac.il/mirror/ftp.zsh.org/pub/zsh/)
 (http://www.math.technion.ac.il/mirror/ftp.zsh.org/pub/zsh/)
+    mydit(Italy)     url(ftp://ftp.unina.it/pub/Unix/pkgs/shell/zsh/)
+(ftp://ftp.unina.it/pub/Unix/pkgs/shell/zsh/)
     mydit(Japan)     url(ftp://ftp.tohoku.ac.jp/mirror/zsh/)
 (ftp://ftp.tohoku.ac.jp/mirror/zsh/)
     mydit()          url(ftp://ftp.nisiq.net/pub/shells/zsh/)
@@ -394,8 +389,6 @@
 (ftp://ftp.math.gatech.edu/pub/zsh/)
     mydit()          url(ftp://uiarchive.uiuc.edu/pub/packages/shells/zsh/)
 (ftp://uiarchive.uiuc.edu/pub/packages/shells/zsh/)
-    mydit()          url(ftp://ftp.sterling.com/zsh/)
-(ftp://ftp.sterling.com/zsh/)
     mydit()          url(ftp://ftp.rge.com/pub/shells/zsh/)
 (ftp://ftp.rge.com/pub/shells/zsh/)
     mydit()          url(ftp://foad.org/pub/zsh/)
@@ -1225,6 +1218,13 @@
   from hiccups introduced by other programmes (kermit has been known to
   do this).
 
+  A problem I have experienced myself (on an AIX 3.2 workstation with
+  xterm) is that termcap deinitialization sequences sent by `less'
+  were causing automargins to be turned off --- not actually a shell
+  problem, but you might have thought it was.  The fix is to put `tt(X)'
+  into the environment variable tt(LESS) to stop the sequences being sent.
+  Other programs (though not zsh) may also send that sequence.
+
   If myem(that)'s not the problem, and you are having difficulties with
   external commands (not part of zsh), and you think some terminal
   setting is wrong (e.g. tt(^V) is getting interpreted as `literal next
@@ -1238,12 +1238,6 @@
   modes it uses itself and a number of special processing characters
   (see the tt(stty(1)) manual page).
 
-  At some point there may be an overhaul which allows the terminal
-  modes used by the shell to be modified separately from those seen by
-  external programmes.  This is partially implemented already: from 2.5,
-  the shell is less susceptible to mode changes inherited from
-  programmes than it used to be.
-
 
 sect(Why does zsh not work in an Emacs shell mode any more?)
 
@@ -1932,6 +1926,8 @@
 
   itemize(
   it() mytt(time) is ignored with builtins and can't be used with mytt({...}).
+  it() When showing completion lists with exactly 80 columns, some
+       terminals print an extra newline which messes up zsh's logic.  
   it() mytt(set -x) (mytt(setopt xtrace)) still has a few glitches; these
      are mostly fixed in 3.1.6.
   it() Zsh's notion of the current line number (via tt($LINENO)) is
@@ -1942,7 +1938,8 @@
   it() The mytt(r) command does not work inside mytt($(...)) or mytt(`...`)
      expansions.   This is fixed in 3.1.
   it() mytt(typeset) handling is non-optimal, particularly with regard to
-     flags, and is ksh-incompatible in unpredictable ways. 
+     flags, and is ksh-incompatible in unpredictable ways.  3.1.6 has
+     been overhauled, but remaining glitches are to be expected.
   it() Nested closures in extended globbing and pattern matching, such as
   verb(
       [[ fofo = (fo#)# ]]
@@ -1975,7 +1972,7 @@
      mytt(compress file) any more.  For this reason, mytt(\M-n) and
      mytt(\M-p) use tt(history-beginning-search-{forward,backward}) which
      search for a line with the same prefix up to the cursor position.
-     From 3.1.6, there is likely to be a different implementation which
+     From 3.1.6, there will be a different implementation which
      makes this closer (though not identical) to the old behaviour.
      The story for the tt({up,down}-line-or-search) commands is similar.
   it() In vi insert mode, the cursor keys no longer work.  The following