added zsh

2 files changed, 126 insertions, 0 deletions

diff --git a/src/SUMMARY.md b/src/SUMMARY.md
index d50c46b..b01baac 100644
--- a/src/SUMMARY.md
+++ b/src/SUMMARY.md
@@ -3,6 +3,7 @@
 - [ld.so](./ld.so.md)
 - [git](./git.md)
 - [bash](./bash.md)
+- [zsh](./zsh.md)
 - [tmux](./tmux.md)
 - [awk](./awk.md)
 - [gdb](./gdb.md)
diff --git a/src/zsh.md b/src/zsh.md
new file mode 100644
index 0000000..ae2a4bc
--- /dev/null
+++ b/src/zsh.md
@@ -0,0 +1,125 @@
+# zsh(1)
+
+## Keybindings
+
+Change input mode:
+```zsh
+bindkey -v              change to vi keymap
+bindkey -e              change to emacs keymap
+```
+
+Define key-mappings:
+```zsh
+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
+```
+
+## Completion
+
+### Installation
+
+Completion functions are provided via files and need to be placed in a location
+covered by `$fpath`. By convention the completion files are names as `_<CMD>`.
+
+A completion skeleton for the command `foo`, stored in `_foo`
+```zsh
+#compdef _foo foo
+
+function _foo() {
+	...
+}
+```
+
+Alternatively one can install a completion function explicitly by calling `compdef <FUNC> <CMD>`.
+
+### Completion Variables
+
+Following variables are available in Completion functions:
+```zsh
+$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`][zsh-comp-utils]
+```zsh
+_describe MSG COMP
+```
+- `MSG` simple string with header message
+- `COMP` array of completions where each entry is `"opt:description"`
+
+```zsh
+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`][zsh-comp-utils]
+```zsh
+_arguments SPEC [SPEC...]
+```
+where `SPEC` can have one of the following forms:
+- `OPT[DESC]:MSG:ACTION`
+- `N:MSG:ACTION`
+
+Available actions
+```zsh
+(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
+```
+
+### Example
+Skeleton to copy/paste for writing simple completions.
+
+Assume a program `foo` with the following interface:
+```zsh
+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`:
+```zsh
+#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]:color:(low high)" \
+        "-f[select file]:file:_files"       \
+        "-d[select dir]:fir:_files -/"      \
+        "-h[help]"
+
+    case $state in
+        s_color) _foo_color;;
+    esac
+}
+```
+
+[zsh-comp-utils]: http://zsh.sourceforge.net/Doc/Release/Completion-System.html#Completion-Functions