Zsh

1
Zsh

• - Larry P. Schrof

2
Purpose

• Spark your interest in zsh
• To learn more about zshs capabilities
• Expand your productivity

3
Topics Covered

• Configuration Files
• Prompt Tricks
• Monitoring Logins
• Aliases
• The Directory Stack
• Brace Expansion
• History Using fc
• History Expansion
• Parameters Arrays and Subscripting

• Parameters Subscript Flags
• Parameters Expansion
• Filename Generation
• Filename Generation Qualifiers
• Programmable Completion
• Completion Items
• Restricted Mode
• ZLE (Zsh Command Line Editor)
• Where to get more information.

4
Configuration Files

• Order
• /etc/zshenv, then /.zshenv
• /etc/zprofile, then /.zprofile (L)
• /etc/zshrc, then /.zshrc (I)
• /etc/zlogin, then /.zlogin (L)
• /etc/zlogout then/.zlogout (logout)
• (I) Only if interactive. (L) Only if login

5
Prompt Tricks

• Arithmetic, command, and parameter expansion
  available.
• Escape sequences start with a (Over 40)
• Conditional Expressions
• (X.true-text.false-text)
• RPROMPT for right-hand side prompt
• Formatting and truncating available

6
Monitoring Logins

• Event format username_at_hostline
• rootconsole
• schrof_at_procmail.org
• Put events in watch parameter
• watch(event1 event2 eventN)
• Set the LOGCHECK parameter
• Formatting available

7
Aliases

• namevalue syntax
• Global aliases! Define with alias -g
• Functions are usually preferred

8
The Directory Stack

• Used for managing large lists of directories
• dirs -v to examine stack
• popd removes a directory from stack, and cds to
  that directory
• pushd cds to a new directory, and places OLDPWD
  on top of the stack
• Can use expansion to reference stack entries

9
Brace Expansion

• Alows you to quickly generate lists in two ways
• ls -l array5d,MYd,BIG
• touch logfile.990801..31.tmp
• zsh is smart about zero padding

10
History Using fc

• fc loads past commands into editor, then executes
  them
• fc -l lists previous commands
• fc -e EDITOR OPTIONS oldnew first
  last
• Options n l d D r t E i m
• fc is not as direct as history expansion, but a
  bit easier to use

11
History Expansion

• Allows you to reference complete or partial past
  commands
• All expansions start with
• Use UP/DOWN arrows in emacs mode
• CTRL-R in emacs mode is your friend.
• oldnew trick
• designatorwordmod1mod2...

12
Parameters Arrays and Subscripting

• Assign name(value1 valueN)
• Subscripts nameexpr
• negative expr counts from end
• Range nameexpr1,expr2
• Replacement nameexprvalue
• value can be an array
• Subscripts work on strings, too!

13
Parameters Subscript Flags

• name(X)expr,(Y)expr2
• w splits by words
• s splits on specified characters
• f splits on a per-line basis
• r treats expr as a pattern returns first item
  matching expr
• i returns index of first match
• R and I just like r and i, but return last match
• n used with r, R, i, or I. Returns nth match.

14
Parameters Expansion

• Standard ksh expansions
• var var-word varword var?
• Adds more expansions
• namepattern namepattern namepattern
• Any of above can be preceded by a for length of
  result.

15
Filename Generation

• Set EXTENDED_GLOB variable
• Operators include , ?, , !, , , lt-gt, ,
  , xy
• / does recursive search
• print -l /usr/local/src//.cho

16
Filename Generation Qualifiers

• Surpasses most other shells
• Limits wildcard matches
• After wildcard, enclose list in ()s
• Over 40 qualifiers available, including negation

17
Programmable Completion

• Set with compctl command
• Fully programmable. If zsh doesnt do what you
  want, you can write it yourself.
• Customizable. (menu? Cycle through list?
  Auto-insert?)
• zsh can complete ANYTHING!

18
Completion Items

• Filenames
• Built-in commands
• External commands
• aliases
• global aliases
• functions
• Shell variables
• Environment variables
• reserved words
• Zsh options
• key bindings

• Named directories
• usernames (files, NIS, etc)
• hosts
• running jobs
• suspended jobs
• Anything else you can imagine.

19
Restricted Mode

• Serves well for a guest account
• http//www.acm.uiuc.edu/workshops/zsh/restricted.h
  tml

20
Command-line editor

• Emacs, vi-insert, and vi-command modes provided
• Build your own keymaps from scratch
• 160 pre-defined widgets
• Write your own widgets
• Rebind any or all portions of keymaps
• bindkey used to select and modify keymaps
• man zshmodules for details

21
More Information

• Workshop
• http//www.acm.uiuc.edu/workshops/zsh
• Homepage
• http//www.zsh.org
• FAQ
• http//sunsite.auc.dk/zsh/FAQ/