From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19645 invoked from network); 24 Apr 2002 21:50:32 -0000 Received: from sunsite.dk (130.225.247.90) by ns1.primenet.com.au with SMTP; 24 Apr 2002 21:50:32 -0000 Received: (qmail 10520 invoked by alias); 24 Apr 2002 21:50:11 -0000 Mailing-List: contact zsh-users-help@sunsite.dk; run by ezmlm Precedence: bulk X-No-Archive: yes X-Seq: 4858 Received: (qmail 10504 invoked from network); 24 Apr 2002 21:50:09 -0000 To: zsh-users@sunsite.auc.dk Subject: Z-Shell (zsh) FAQ changes this month Date: Wed, 24 Apr 2002 21:55:34 +0100 From: Peter Stephenson Message-Id: <20020424205539.821001C0A2@pwstephenson.fsnet.co.uk> 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. Archive-Name: unix-faq/shell/zsh Last-Modified: 2002/04/24 Submitted-By: pws@pwstephenson.fsnet.co.uk (Peter Stephenson) Posting-Frequency: Monthly Copyright: (C) P.W. Stephenson, 1995--2001 (see end of document) Changes since last issue posted: passim Be more explicit about how to set options. 1.7 More care about infinite loops exec'ing zsh. 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? 3.25. How do I get coloured prompts on my colour xterm? 3.26. Why is my output duplicated with `foo 2>&1 >foo.out | bar'? 3.27. Why am I prompted to correct commands which are in my path? 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. Did 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://zsh.sunsite.dk/ . The server provides this FAQ and much else and is now maintained by Karsten Thygesen and others (mail zsh@sunsite.dk with any related messages). The FAQ is at http://zsh.sunsite.dk/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://zsh.sunsite.dk/FAQ/zshfaq.yo and the plain text version can be found at http://zsh.sunsite.dk/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@rtfm.mit.edu 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. I have been putting together a user guide to complement the manual by explaining the most useful features of zsh in a more easy to read way. This is now more than half complete and includes a discussion of the new form for command line completion, not described in the FAQ. You can find it in various formats at: http://zsh.sunsite.dk/Guide/ (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 --- Minor changes of phrasing, spelling, etc. are not included. 1.7: I don't have root access: how do I make zsh my login shell? Unfortunately, on many machines you can't use `chsh' to change your shell unless the name of the shell is contained in /etc/shells, so if you have your own copy of zsh you need some sleight-of-hand to use it when you log on. (Simply typing `zsh' is not really a solution since you still have your original login shell waiting for when you exit.) The basic idea is to use `exec ' to replace the current shell with zsh. Often you can do this in a login file such as .profile (if your shell is sh or ksh) or .login (if it's csh). Make sure you have some way of altering the file (e.g. via FTP) before you try this as `exec' is often rather unforgiving. If you have zsh in a subdirectory `bin' of your home directory, put this in .profile: [ x$ZSH_VERSION = x -a -f $HOME/bin/zsh ] && exec $HOME/bin/zsh -l --- the first test is a safeguard to avoid an infinite loop in case your zsh is set up to source your .profile, which is quite a common trick as you can save a lot of duplication that way. If your login shell is csh or tcsh, put this in .login: if ( -f ~/bin/zsh ) exec ~/bin/zsh -l (in each case the `-l' tells zsh it is a login shell). If you want to check this works before committing yourself to it, you can make the login shell ask whether to exec zsh. The following work for Bourne-like shells: [ -f $HOME/bin/zsh ] && { echo "Type Y to run zsh: \c" read line [ "$line" = Y ] && exec $HOME/bin/zsh -l } and for C-shell-like shells: if ( -f ~/bin/zsh ) then echo -n "Type Y to run zsh: " if ( "$<" == Y ) exec ~/bin/zsh -l endif It's not a good idea to put this (even without the -l) into .cshrc, at least without some tests on what the csh is supposed to be doing, as that will cause _every_ instance of csh to turn into a zsh and will cause csh scripts (yes, unfortunately some people write these) which do not call `csh -f' to fail. If you want to tell xterm to run zsh, change the SHELL environment variable to the full path of zsh at the same time as you exec zsh (in fact, this is sensible for consistency even if you aren't using xterm). If you have to exec zsh from your .cshrc, a minimum safety check is `if ($?prompt) exec zsh'. If you like your login shell to appear in the process list as `-zsh', you can link `zsh' to `-zsh' (e.g. by `ln -s ~/bin/zsh ~/bin/-zsh') and change the exec to `exec -zsh'. (Make sure `-zsh' is in your path.) This has the same effect as the `-l' option. There was a thread on this topic on the zsh-workers mailing list, starting from item 15747. You can find this at http://www.zsh.org/mla/. Footnote: if you DO have root access, make sure zsh goes in /etc/shells on all appropriate machines, including NIS clients, or you may have problems with FTP to that machine. 2.1: Differences from sh and ksh (The following refers to shell options extensively. To turn an option on in zsh you use `setopt var(optionname)', and to turn it off you use `unsetopt var(optionname)'. The option name is case insensitive and underscores are ignored. If you are used to ksh, that syntax works too.) Most features of ksh (and hence also of sh) are implemented in zsh; problems can arise because the implementation is slightly different. Note also that not all ksh's are the same either. I have based this on the 11/16/88f version of ksh; differences from ksh93 will be more substantial. As a summary of the status: 1) because of all the options it is not safe to assume a general zsh run by a user will behave as if sh or ksh compatible; 2) invoking zsh as sh or ksh (or if either is a symbolic link to zsh) sets appropriate options and improves compatibility (from within zsh itself, calling `ARGV0=sh zsh' will also work); 3) from version 3.0 onward the degree of compatibility with sh under these circumstances is very high: zsh can now be used with GNU configure or perl's Configure, for example; 4) the degree of compatibility with ksh is also high, but a few things are missing: for example the more sophisticated pattern-matching expressions are different for versions before 3.1.3 --- see the detailed list below; 5) also from 3.0, the command `emulate' is available: `emulate ksh' and `emulate sh' set various options as well as changing the effect of single-letter option flags as if the shell had been invoked with the appropriate name. Including the command `emulate sh; setopt localoptions' in a shell function will turn on sh emulation for that function only. In 4.0 (and in 3.0.6 through 8), this can be abbreviated as `emulate -L sh'. The classic difference is word splitting, discussed in question 3.1; this catches out very many beginning zsh users. As explained there, this is actually a bug in every other shell. The answer is to set SH_WORD_SPLIT for backward compatibility. The next most classic difference is that unmatched glob patterns cause the command to abort; set NO_NOMATCH for those. Here is a list of various options which will increase ksh compatibility, though maybe decrease zsh's abilities: see the manual entries for GLOB_SUBST, IGNORE_BRACES (though brace expansion occurs in some versions of ksh), KSH_ARRAYS, KSH_GLOB, KSH_OPTION_PRINT, LOCAL_OPTIONS, NO_BAD_PATTERN, NO_BANG_HIST, NO_EQUALS, NO_HUP, NO_NOMATCH, NO_RCS, NO_SHORT_LOOPS, PROMPT_SUBST, RM_STAR_SILENT, POSIX_BUILTINS, SH_FILE_EXPANSION, SH_GLOB, SH_OPTION_LETTERS, SH_WORD_SPLIT (see question 3.1) and SINGLE_LINE_ZLE. Note that you can also disable any built-in commands which get in your way. If invoked as `ksh', the shell will try to set suitable options. Here are some differences from ksh which might prove significant for ksh programmers, some of which may be interpreted as bugs; there must be more. Note that this list is deliberately rather full and that most of the items are fairly minor. Those marked `*' perform in a ksh-like manner if the shell is invoked with the name `ksh', or if `emulate ksh' is in effect. Capitalised words with underlines refer to shell options. o Syntax: o * Shell word splitting: see question 3.1. o * Arrays are (by default) more csh-like than ksh-like: subscripts start at 1, not 0; array[0] refers to array[1]; `$array' refers to the whole array, not $array[0]; braces are unnecessary: $a[1] == ${a[1]}, etc. Set the KSH_ARRAYS option for compatibility. o Coprocesses are established by `coproc'; `|&' behaves like csh. Handling of coprocess file descriptors is also different. o In `cmd1 && cmd2 &', only `cmd2' instead of the whole expression is run in the background in zsh. The manual implies this is a bug. Use `{ cmd1 && cmd2 } &' as a workaround. o Command line substitutions, globbing etc.: o * Failure to match a globbing pattern causes an error (use NO_NOMATCH). o * The results of parameter substitutions are treated as plain text: `foo="*"; print $foo' prints all files in ksh but `*' in zsh (uset GLOB_SUBST). o * $PSn do not do parameter substitution by default (use PROMPT_SUBST). o * Standard globbing does not allow ksh-style `pattern-lists'. Equivalents: ---------------------------------------------------------------------- ksh zsh Meaning ------ ------ --------- !(foo) ^foo Anything but foo. or foo1~foo2 Anything matching foo1 but foo2[1]. @(foo1|foo2|...) (foo1|foo2|...) One of foo1 or foo2 or ... ?(foo) (foo|) Zero or one occurrences of foo. *(foo) (foo)# Zero or more occurrences of foo. +(foo) (foo)## One or more occurrences of foo. ---------------------------------------------------------------------- The `^', `~' and `#' (but not `|')forms require EXTENDED_GLOB. From version 3.1.3, the ksh forms are fully supported when the option KSH_GLOB is in effect; for previous versions you must use the table above. [1] Note that `~' is the only globbing operator to have a lower precedence than `/'. For example, `**/foo~*bar*' matches any file in a subdirectory called `foo', except where `bar' occurred somewhere in the path (e.g. `users/barstaff/foo' will be excluded by the `~' operator). As the `**' operator cannot be grouped (inside parentheses it is treated as `*'), this is the way to exclude some subdirectories from matching a `**'. o Unquoted assignments do file expansion after `:'s (intended for PATHs). o `integer' does not allow `-i'. o `typeset' and `integer' have special behaviour for assignments in ksh, but not in zsh. For example, this doesn't work in zsh: integer k=$(wc -l ~/.zshrc) because the return value from wc includes leading whitespace which causes wordsplitting. Ksh handles the assignment specially as a single word. o Command execution: o * There is no $ENV variable (use /etc/zshrc, ~/.zshrc; note also $ZDOTDIR). o $PATH is not searched for commands specified at invocation without -c. o Aliases and functions: o The order in which aliases and functions are defined is significant: function definitions with () expand aliases -- see question 2.3. o Aliases and functions cannot be exported. o There are no tracked aliases: command hashing replaces these. o The use of aliases for key bindings is replaced by `bindkey'. o * Options are not local to functions (use LOCAL_OPTIONS; note this may always be unset locally to propagate options settings from a function to the calling level). o Functions defined with `function funcname { body }' behave the same way as those defined with `funcname () { body }'. In ksh, the former behave as if the body were read from a file with `.', and only the latter behave as true functions. o Traps and signals: o * Traps are not local to functions. The option LOCAL_TRAPS is available from 3.1.6. o TRAPERR has become TRAPZERR (this was forced by UNICOS which has SIGERR). o Editing: o The options emacs, gmacs, viraw are not supported. Use bindkey to change the editing behaviour: `set -o {emacs,vi}' becomes `bindkey -{e,v}'; for gmacs, go to emacs mode and use `bindkey \^t gosmacs-transpose-characters'. o The `keyword' option does not exist and `-k' is instead interactivecomments. (`keyword' will not be in the next ksh release either.) o * Management of histories in multiple shells is different: the history list is not saved and restored after each command. The option SHARE_HISTORY appeared in 3.1.6 and is set in ksh compatibility mode to remedy this. o `\' does not escape editing chars (use `^V'). o Not all ksh bindings are set (e.g. `#'; try `q'). o * `#' in an interactive shell is not treated as a comment by default. o Built-in commands: o Some built-ins (r, autoload, history, integer ...) were aliases in ksh. o There is no built-in command newgrp: use e.g. `alias newgrp="exec newgrp"' o `jobs' has no `-n' flag. o `read' has no `-s' flag. o Other idiosyncrasies: o `select' always redisplays the list of selections on each loop. --- End of changed items, diff from previous version follows --- Index: zshfaq.yo =================================================================== RCS file: /pack/anoncvs/zsh/www/FAQ/zshfaq.yo,v retrieving revision 1.78 retrieving revision 1.79 diff -u -r1.78 -r1.79 --- zshfaq.yo 2002/03/24 19:23:57 1.78 +++ zshfaq.yo 2002/04/24 21:09:46 1.79 @@ -43,11 +43,11 @@ whenman(report(ARG1)(ARG2)(ARG3))\ whenms(report(ARG1)(ARG2)(ARG3))\ whensgml(report(ARG1)(ARG2)(ARG3))) -myreport(Z-Shell Frequently-Asked Questions)(Peter Stephenson)(2002/03/24) +myreport(Z-Shell Frequently-Asked Questions)(Peter Stephenson)(2002/04/24) COMMENT(-- the following are for Usenet and must appear first)\ description(\ mydit(Archive-Name:) unix-faq/shell/zsh -mydit(Last-Modified:) 2002/03/24 +mydit(Last-Modified:) 2002/04/24 mydit(Submitted-By:) email(pws@pwstephenson.fsnet.co.uk (Peter Stephenson)) mydit(Posting-Frequency:) Monthly mydit(Copyright:) (C) P.W. Stephenson, 1995--2001 (see end of document) @@ -55,7 +55,8 @@ bf(Changes since last issue posted:) description( - mydit(2.3) More description about alias pitfalls. + mydit(passim) Be more explicit about how to set options. + mydit(1.7) More care about infinite loops exec'ing zsh. ) This document contains a list of frequently-asked (or otherwise @@ -448,9 +449,12 @@ If you have zsh in a subdirectory mytt(bin) of your home directory, put this in .profile: verb( - [ -f $HOME/bin/zsh ] && exec $HOME/bin/zsh -l + [ x$ZSH_VERSION = x -a -f $HOME/bin/zsh ] && exec $HOME/bin/zsh -l ) - or if your login shell is csh or tcsh, put this in .login: + --- the first test is a safeguard to avoid an infinite loop in case + your zsh is set up to source your tt(.profile), which is quite a common + trick as you can save a lot of duplication that way. If your login + shell is csh or tcsh, put this in .login: verb( if ( -f ~/bin/zsh ) exec ~/bin/zsh -l ) @@ -510,6 +514,12 @@ sect(Differences from sh and ksh) label(21) + (The following refers to shell options extensively. To turn an + option on in zsh you use `tt(setopt) var(optionname)', and to turn + it off you use `tt(unsetopt) var(optionname)'. The option name is + case insensitive and underscores are ignored. If you are used to ksh, + that syntax works too.) + Most features of ksh (and hence also of sh) are implemented in zsh; problems can arise because the implementation is slightly different. Note also that not all ksh's are the same either. I have based this @@ -1496,14 +1506,14 @@ substitution then sets a default to which later history substitutions with single unqualified bangs refer, so that !$ becomes equivalent to tt(!-2:$). The option tt(CSH_JUNKIE_HISTORY) makes all single bangs refer - to the last command. + to the last command (`tt(setopt cshjunkiehistory)' to turn it on). sect(Why does zsh kill off all my background jobs when I logout?) Simple answer: you haven't asked it not to. Zsh (unlike [t]csh) gives - you the option of having background jobs killed or not: the mytt(nohup) - option exists if you don't want them killed. Note that you can always + you the option of having background jobs killed or not: `tt(setopt nohup)' + if you don't want them killed. Note that you can always run programs with mytt(nohup) in front of the pipeline whether or not the option is set, which will prevent that job from being killed on logout. (mytt(nohup) is actually an external command.) @@ -1746,7 +1756,7 @@ to both files when the redirector appears twice. What's going on in the first example is exactly the same, however the second redirector is disguised as a pipe. So if you want to turn this effect off, you need - to unset the option mytt(MULTIOS). + to `tt(unsetopt multios)'. sect(Why am I prompted to correct commands which are in my path?) @@ -1874,7 +1884,8 @@ Often there will be more than one possible completion: two files start with the same characters, for example. Zsh has a lot of - flexibility for what it does here via its options. The default is + flexibility for what it does here via its options (use `tt(setopt) + var(optioname)' to turn an option on). The default is for it to beep and completion to stop until you type another character. You can type tt(\C-D) to see all the possible completions. (That's assuming you're at the end of the line, otherwise tt(\C-D) will @@ -1915,7 +1926,7 @@ in zsh, it will simply go to the end of the word and try to complete there. However, there are two ways of changing this. - First, there is the option COMPLETE_IN_WORD. This tries to fill in + First, you can `tt(setopt complete_in_word)'. This tries to fill in the word at the point of the cursor. For example, if the current directory contains mytt(foobar), then with the option set, you can complete mytt(fbar) to mytt(foobar) by moving the cursor to the