Change input mode:

bindkey -v              change to vi keymap
bindkey -e              change to emacs keymap

Define key-mappings:

bindkey                 list mappings in current keymap
bindkey in-str cmd      create mapping for `in-str` to `cmd`
bindkey -r in-str       remove binding for `in-str`

# C-v <key>             dump <key> code, which can be used in `in-str`
# zle -l                list all functions for keybindings
# man zshzle(1)         STANDARD WIDGETS: get description of functions

Access edit buffer in zle widget:

$BUFFER       # Entire edit buffer content
$LBUFFER      # Edit buffer content left to cursor
$RBUFFER      # Edit buffer content right to cursor

# create zle widget which adds text right of the cursor
function add-text() {
    RBUFFER="some text $RBUFFER"
zle -N add-text

bindkey "^p" add-text


Default value:

# default value
echo ${foo:-defval}   # defval
echo ${foo:-defval}   # bar

Alternative value:

echo ${foo:+altval}   # ''
echo ${foo:+altval}   # altval

Check variable set, error if not set:

echo ${foo:?msg}      # print `msg` and return errno `1`
echo ${foo:?msg}      # bar

Sub-string ${var:offset:length}:

echo ${foo:1:3}       # bcd

Trim prefix ${var#prefix}:

echo ${foo#bar}       # .baz

Trim suffix ${var%suffix}:

echo ${foo%.baz}      # bar

Substitute pattern ${var/pattern/replace}:

echo ${foo/bb/XX}    # aaXXccbbdd
echo ${foo//bb/XX}   # aaXXccXXdd
# replace prefix
echo ${foo/#bb/XX}   # aabbccbbdd
echo ${foo/#aa/XX}   # XXbbccbbdd
# replace suffix
echo ${foo/%bb/XX}   # aabbccbbdd
echo ${foo/%dd/XX}   # aabbccbbXX

Note: prefix/suffix/pattern are expanded as pathnames.


# Variable with local scope
local var=val

# Read-only variable
readonly var=bal

Indexed arrays:

arr=(aa bb cc dd)
echo $arr[1]           # aa
echo $arr[-1]          # dd

echo $arr[-1]          # ee

echo $arr[1,3]         # aa bb cc

Associative arrays:

typeset -A arr
echo $arr[x]           # aa

Tied arrays:

typeset -T VEC vec=(1 2 3) '|'

echo $vec              # 1 2 3
echo $VEC              # 1|2|3

Unique arrays (set):

typeset -U vec=(1 2 3)

echo $vec             # 1 2 3
vec+=(1 2 4)
echo $vec             # 1 2 3 4

Expansion Flags

Join array to string j:sep::

foo=(1 2 3 4)
echo ${(j:-:)foo}     # 1-2-3-4
echo ${(j:\n:)foo}    # join with new lines

Split string to array s:sep:

bar=(${(s:-:)foo})    # capture as array
echo $bar             # 1 2 3 4
echo $bar[2]          # 2

Upper/Lower case string:

echo ${(L)foo}        # aabb
echo ${(U)foo}        # AABB

Key/values in associative arrays:

typeset -A vec; vec[a]='aa'; vec[b]='bb'

echo ${(k)vec}        # a b
echo ${(v)vec}        # aa bb
echo ${(kv)vec}       # a aa b bb

# Iterate over key value pairs.
for k v in ${(kv)vec)}; do ...; done

I/O redirections

See bash - I/O redirection

Process substitution

Process substitution allows to redirect the stdout of multiple processes at once.

vim -d <(grep foo bar) <(grep foo moose)

Argument parsing with zparseopts

zparseopts [-D] [-E] [-A assoc] specs

Arguments are copied into the associative array assoc according to specs. Each spec is described by an entry as opt[:][=array].

  • opt is the option without the - char. Passing -f is matched against f opt, --long is matched against -long.
  • Using : means the option will take an argument.
  • The optional =array specifies an alternate storage container where this option should be stored.

Documentation can be found in man zshmodules.


function test() {
    zparseopts -D -E -A opts f=flag o: -long:
    echo "flag $flag"
    echo "o    $opts[-o]"
    echo "long $opts[--long]"
    echo "pos  $1"


# Outputs:
#   flag -f
#   o    OPTION
#   long LONG_OPT

Regular Expressions

Zsh supports regular expression matching with the binary operator =~. The match results can be accessed via the $MATCH variable and $match indexed array:

  • $MATCH contains the full match
  • $match[1] contains match of the first capture group
INPUT='title foo : 1234'
REGEX='^title (.+) : ([0-9]+)$'
if [[ $INPUT =~ $REGEX ]]; then
    echo "$MATCH"       # title foo : 1234
    echo "$match[1]"    # foo
    echo "$match[2]"    # 1234



Completion functions are provided via files and need to be placed in a location covered by $fpath. By convention the completion files are names as _<CMD>.

A completion skeleton for the command foo, stored in _foo

#compdef _foo foo

function _foo() {

Alternatively one can install a completion function explicitly by calling compdef <FUNC> <CMD>.

Completion Variables

Following variables are available in Completion functions:

$words              # array with command line in words
$#words             # number words
$CURRENT            # index into $words for cursor position
$words[CURRENT-1]   # previous word (relative to cursor position)

Completion Functions

  • _describe simple completion, just words + description
  • _arguments sophisticated completion, allow to specify actions

Completion with _describe

_describe MSG COMP
  • MSG simple string with header message
  • COMP array of completions where each entry is "opt:description"
function _foo() {
    local -a opts
    opts=('bla:desc for bla' 'blu:desc for blu')
    _describe 'foo-msg' opts
compdef _foo foo

foo <TAB><TAB>
 -- foo-msg --
bla  -- desc for bla
blu  -- desc for blu

Completion with _arguments

_arguments SPEC [SPEC...]

where SPEC can have one of the following forms:

  • OPT[DESC]:MSG:ACTION for option flags
  • N:MSG:ACTION for positional arguments

Available actions

(op1 op2)   list possible matches
->VAL       set $state=VAL and continue, `$state` can be checked later in switch case
FUNC        call func to generate matches
{STR}       evaluate `STR` to generate matches


Skeleton to copy/paste for writing simple completions.

Assume a program foo with the following interface:

foo -c green|red|blue -s low|high -f <file> -d <dir> -h

The completion handler could be implemented as follows in a file called _foo:

#compdef _foo foo

function _foo_color() {
    local colors=()
    colors+=('green:green color')
    colors+=('red:red color')
    colors+=('blue:blue color')
    _describe "color" colors

function _foo() {
    _arguments                              \
        "-c[define color]:color:->s_color"  \
        "-s[select sound]:sound:(low high)" \
        "-f[select file]:file:_files"       \
        "-d[select dir]:dir:_files -/"      \

    case $state in
        s_color) _foo_color;;

Example with optional arguments

For this example we assume that the command foo takes at least three optional arguments such as

foo arg1 arg2 arg3 [argN..]
function _foo() {
    _arguments              \
        "1:opt 1:(a b c)"   \
        ":opt next:(d e f)" \
        "*:opt all:(u v w)"


  • 1:MSG:ACTION sets completion for the first optional argument
  • :MSG:ACTION sets completion for the next optional argument
  • *:MSG:ACTION sets completion for the optional argument where none of the previous rules apply, so in our example for arg3, argN...

_files is a zsh builtin utility function to complete files/dirs see