zsh学习笔记

Configure

Starts up files

/etc/zshenv
~/.zshenv
IF the shell is a login shell, /etc/zprofile and ~/.zprofile
IF the shell is interactive, /etc/zshrc and ~/.zshrc
IF the shell is a login shell, /etc/zlogin and ~/.zlogin

Logging out

/etc/zlogout is read, and then ZDOTDIR/.zlogout

Two terms

A login shell is generally one that is spawned at login time. (IE, by either /bin/login or some other daemon that handles incoming connections). If you telnet, rlogin, rsh, or ssh to a host, chances are you have a login shell. An interactive shell is one in which prompts are displayed and the user types in commands to the shell. (IE, a tty is associated with the shell)

For example, if I run the command

ssh SOME_HOST some_command

I will be running (presumably) a non-interactive program called some_command. This means that zsh will not be an interactive shell, and ignore the corresponding files. Zsh should, however, be a login shell, and read the appropriate files.

Zsh options

Over 100 options.
case-insensitive.
underscores are ignored. SOME_OPTION == SOMEOPTION

setopt OPTION_NAME <— Turn an option on
unsetopt OPTION_NAME <— Turn an option off
setopt NO_OPTION_NAME <— Turen an option off too!

Zsh Prompts (提示符)

primary: contained in the shell variable PROMPT, also known as PS1
IF PROMPT_SUBST is on: the prompts are first subjected to parameter expansion, command substitution, and arithmetic expansion, before actually displays them.

Customize

Over 40 special escape sequences to control information
current time, date, host info, current directory, etc…

Watching for other users

Events

The user who logged in/out: use their username
The host where the user was connected from: use @ followed by the remote hostname
The line(tty) that the user was connected on: use % followed by the line name(ie, pts/186)

Telling zsh to look for events

watch=all
watch=$USERNAME
watch=(event1 event2 ... eventN)

Obtaining the report

Setting LOGCHECK to interger n will cause zsh to report monitored events every n seconds.(default 60)

Then run log at any time.

Conveniences

Aliases

Every token in the input is checked to see if there is an alias defined for it. If there is, the token will be replaced by the alias value IF:

The token is in command position OR
The alias is global (See below) OR
The previous word on the line was an alias whose value ended in a space.

Using

The formal syntax of the zsh alias builtin is:

alias [ -gmrL ] [ name[=value] ... ]

The -r argument tells the alias command to operate on regular aliases.
The -g argument tells the alias command to operate on global aliases.
Without either the r or g flags, alias operates on both types.

For each name with no value, zsh will print the name and what it is aliased to.

With no arguments at all, alias prints the values of ALL defined aliases

With the -L argument, the output from alias is suitable to cut-and-paste into your startup scripts.

To define one or more aliases, simply enter

alias name1=value1 name2=value2 ... nameX=valueX

For each name with a corresponding value, zsh defines an alias with that value.

Global aliases

zsh lets you use aliases even if they are not the first word on the command line. These kinds of aliases are called global aliases.

alias -g

List aliases that match pattern

alias -m

Disable or delete aliases

delete: unalias foo
temporarily disable: disable -a foo
enable back: enable -a foo

Use the origin command

=ftp or \ftp.

Command `cd`

cd == chdir

First form

cd: cd ${HOME}
cd NEW_DIR: Place you in the directory called NEW_DIR
cd -: cd ${OLDPWD}

zsh adds some usefull functionality:

First, if zsh doesn’t find NEW_DIR in the current directory (and NEW_DIR isn’t an absolute path), zsh looks at the shell variable cdpath. It looks for a subdirectory NEW_DIR in each directory of cdpath. If zsh sees NEW_DIR, it goes there.

Furthermore, you can store the FULL pathname of directory in a shell variable.

XDIR=/usr/lib/X11
cd XDIR # without the "$"

XDIR is a named directory

Second form

cd OLD NEW

and zsh replaced any occurance of OLD in the current directory with NEW, and then cd’s into it.

Third form

Pull an entry from the direcotry stack.

cd +n
cd -n

dirs -v to see the direcotry stack.

Arguments

All forms of the cd builtin can take a few arguments:

cd -s DIR Don’t cd into DIR if DIR’s path contains symlinks
cd -P DIR Resolve all symlinks to their true values before changing to DIR
cd -L DIR Symlinks are followed, ignoring the CHASE_LINKS option)

Note: Turning on the shell option CHASE_LINKS is the same as the -P argument to cd.

Directory stack

Zsh has an internal directory stack. This is a facility that can help you manage working in many different direcotries throughout your zsh login session.

pushd: place onto the direcotry stack
popd: get and remove one from the stack top

Command `dirs`

dirs -v  # view the contents of the stack
dirs dir1 dir2 ... dirN  # rebuild the stack, staring with the rightmost dirN, and push $PWD on the top

`popd`, `pushd`

TODO

Filename Expansion and the Directory Stack

Zsh offers a nice way to reference the directory stack quickly in your daily work. The description below is taken directly from the man page:

A ~ followed by a number is replaced by the directory at that position in the directory stack.
~0 is equivalent to ~+, and ~1 is the top of the stack.
~+ followed by a number is replaced by the directory at that position in the directory stack.
~+0 is equivalent to ~+, and ~+1 is the top of the stack.
~- followed by a number is replaced by the directory that many positions from the bottom of the stack.
~-0 is the bottom of the stack.
The PUSHD_MINUS option exchanges the effects of ~+ and ~- where they are followed by a number.

Brace Expansion

Brace expansion is a convenient feature that allows you to generate lists of items quickly on the command line.

echo str{xx,yy,zz}
echo logfile.1610{01..31}.log

Programing Zsh

Parameters

names: can be any sequence of alpha-numeric characters and underscores. (There are a few special cases, namely * , @ , # , ? , - , $ , and !)
values: the pieces of information that variables store.
Values in zsh can be one of three types: strings, integers, or arrays.

Assigning values

name=value
name=(value1 value2 ... valueN) # array parameter
unset PARAMETER_NAME # delete parameter

Scope

Shell functions delimit scope for shell parameters.
If you assign a value to a variable that doesn’t exist, the variable gets created in the outermost scope.
If a variable X goes out of scope, it gets deleted. (Just like in C).

Positional parameters

start with the number 0
can go past 9. So $11 is the 11th argument.
contain all the positional parameters: &, *, argv

Array Parameters

array_name=(value1 value2 ... valueN)
set -A array_name value1 value2 .. valueN

Single element subscripts

subscripts are used to select one of more individual items from an array. zsh’s mechanism for subscripting into arrays is so powerful, it can be considered superior to many programming languages.

The index are start from 1.

some_array[expr]
ARGV[-2]

Obtaining Multiple Consecutive Elements

some_array[expr1,expr2]

This returns elements (in some_array) starting from expr1, up to and including expr2.

Again, the expressions are evaluated to integers before being used, and negative numbers are used in the same way as descibed above.

Subscripts can be included with variable names inside curly braces…

${friends[2,5]}

Replacing Portions of Arrays

> veg=(lettuce carrot celery tomato onion)
> echo $veg
lettuce carrot celery tomato onion
> veg[4]=(pepper radish)
> echo $veg
lettuce carrot celery pepper radish onion

Subscripting Strings

This item is not quite related to arrays, but it’s too useful to pass up.

Sbscript flags

TODO

Parameter expansion

TODO

Filename generation

TODO

Modifiers

TODO

Filename qualifiers

TODO

Programmable completion

Before proceeding, keep the zshcompctl man page in mind.

Completion refers to zsh’s ability to finish your command lines for you. It comes in many forms. By default, the < TAB > key is bound to a completion command in zsh.

Filenames are the default item to complete on. In zsh, ANYTHING can be completed, including:

Filenames
Filesystems paths
builtin commands
external commands
aliases
shell functions
reserved words
global aliases
disabled hash table elements
shell options
shell parameter names
environment variables
named directories
key bindings
running jobs
suspended jobs
user names
anything else you can imagine - you can program it yourself easily.

zsh学习笔记

发布于 2016-10-27 21:59:30

Configure

Starts up files

Logging out

Two terms

Zsh options

Zsh Prompts (提示符)

Customize

Watching for other users

Events

Telling zsh to look for events

Obtaining the report

Conveniences

Aliases

Using

Global aliases

List aliases that match pattern

Disable or delete aliases

Use the origin command

Command cd

First form

Second form

Third form

Arguments

Directory stack

Command dirs

popd, pushd

Filename Expansion and the Directory Stack

Brace Expansion

Programing Zsh

Parameters

Array Parameters

Single element subscripts

Obtaining Multiple Consecutive Elements

Replacing Portions of Arrays

Subscripting Strings

Sbscript flags

Parameter expansion

Filename generation

Modifiers

Filename qualifiers

Programmable completion

Links

Command `cd`

Command `dirs`

`popd`, `pushd`