add zsh support

core/commands/commands.go

@@ -13,7 +13,7 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/ipfs/go-ipfs-cmds"
+	cmds "github.com/ipfs/go-ipfs-cmds"
 )
 
 type commandEncoder struct {
@@ -169,6 +169,30 @@ To install the completions permanently, they can be moved to
 					return res.Emit(&buf)
 				},
 			},
+			"zsh": {
+				Helptext: cmds.HelpText{
+					Tagline:          "Generate zsh shell completions.",
+					ShortDescription: "Generates command completions for the zsh shell.",
+					LongDescription: `
+Generates command completions for the zsh shell.
+The simplest way to see it working is write the completions
+to a file and then source it:
+  > ipfs commands completion zsh > ipfs-completion.zsh
+  > source ./ipfs-completion.zsh
+To install the completions permanently, they can be moved to
+/etc/zsh/completions or sourced from your ~/.zshrc file.
+`,
+				},
+				NoRemote: true,
+				Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
+					var buf bytes.Buffer
+					if err := writeZshCompletions(root, &buf); err != nil {
+						return err
+					}
+					res.SetLength(uint64(buf.Len()))
+					return res.Emit(&buf)
+				},
+			},
 			"fish": {
 				Helptext: cmds.HelpText{
 					Tagline:          "Generate fish shell completions.",

core/commands/completion.go

@@ -83,7 +83,7 @@ func commandToCompletions(name string, fullName string, cmd *cmds.Command) *comp
 	return parsed
 }
 
-var bashCompletionTemplate, fishCompletionTemplate *template.Template
+var bashCompletionTemplate, fishCompletionTemplate, zshCompletionTemplate *template.Template
 
 func init() {
 	commandTemplate := template.Must(template.New("command").Parse(`
@@ -153,6 +153,28 @@ _ipfs() {
   {{ template "command" . }}
 }
 complete -o nosort -o nospace -o default -F _ipfs ipfs
+`))
+
+	zshCompletionTemplate = template.Must(commandTemplate.New("root").Parse(`#!bin/zsh
+autoload bashcompinit
+bashcompinit
+_ipfs_compgen() {
+local oldifs="$IFS"
+IFS=$'\n'
+while read -r line; do
+	COMPREPLY+=("$line")
+done < <(compgen "$@")
+IFS="$oldifs"
+}
+
+_ipfs() {
+COMPREPLY=()
+local index=1
+local argidx=0
+local word="${COMP_WORDS[COMP_CWORD]}"
+{{ template "command" . }}
+}
+complete -o nosort -o nospace -o default -F _ipfs ipfs
 `))
 
 	fishCommandTemplate := template.Must(template.New("command").Parse(`
@@ -222,3 +244,8 @@ func writeFishCompletions(cmd *cmds.Command, out io.Writer) error {
 	cmds := commandToCompletions("ipfs", "", cmd)
 	return fishCompletionTemplate.Execute(out, cmds)
 }
+
+func writeZshCompletions(cmd *cmds.Command, out io.Writer) error {
+	cmds := commandToCompletions("ipfs", "", cmd)
+	return zshCompletionTemplate.Execute(out, cmds)
+}