Allow commands' partial match

command.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"sort"
+	"strings"
 	"text/tabwriter"
 )
 
@@ -94,30 +95,45 @@ func (c Cmd) HelpText() string {
 }
 
 // findChildCmd returns the subcommand with matching name or alias.
-func (c *Cmd) findChildCmd(name string) *Cmd {
+func (c *Cmd) findChildCmd(name string, partialMatch bool) *Cmd {
 	// find perfect matches first
 	if cmd, ok := c.children[name]; ok {
 		return cmd
 	}
 
+	var prefixes []*Cmd
+
 	// find alias matching the name
 	for _, cmd := range c.children {
+		if partialMatch && strings.HasPrefix(cmd.Name, name) {
+			prefixes = append(prefixes, cmd)
+		}
+
 		for _, alias := range cmd.Aliases {
 			if alias == name {
 				return cmd
 			}
+
+			if partialMatch && strings.HasPrefix(alias, name) {
+				prefixes = append(prefixes, cmd)
+			}
 		}
 	}
 
+	// allow only unique partial match
+	if len(prefixes) == 1 {
+		return prefixes[0]
+	}
+
 	return nil
 }
 
 // FindCmd finds the matching Cmd for args.
 // It returns the Cmd and the remaining args.
-func (c Cmd) FindCmd(args []string) (*Cmd, []string) {
+func (c Cmd) FindCmd(args []string, partialMatch bool) (*Cmd, []string) {
 	var cmd *Cmd
 	for i, arg := range args {
-		if cmd1 := c.findChildCmd(arg); cmd1 != nil {
+		if cmd1 := c.findChildCmd(arg, partialMatch); cmd1 != nil {
 			cmd = cmd1
 			c = *cmd
 			continue

command_test.go

@@ -33,19 +33,19 @@ func TestFindCmd(t *testing.T) {
 	cmd := newCmd("root", "")
 	cmd.AddCmd(newCmd("child1", ""))
 	cmd.AddCmd(newCmd("child2", ""))
-	res, err := cmd.FindCmd([]string{"child1"})
+	res, err := cmd.FindCmd([]string{"child1"}, false)
 	if err != nil {
 		t.Fatal("finding should work")
 	}
 	assert.Equal(t, res.Name, "child1")
 
-	res, err = cmd.FindCmd([]string{"child2"})
+	res, err = cmd.FindCmd([]string{"child2"}, false)
 	if err != nil {
 		t.Fatal("finding should work")
 	}
 	assert.Equal(t, res.Name, "child2")
 
-	res, err = cmd.FindCmd([]string{"child3"})
+	res, err = cmd.FindCmd([]string{"child3"}, false)
 	if err == nil {
 		t.Fatal("should not find this child!")
 	}
@@ -58,19 +58,49 @@ func TestFindAlias(t *testing.T) {
 	subcmd.Aliases = []string{"alias1", "alias2"}
 	cmd.AddCmd(subcmd)
 
-	res, err := cmd.FindCmd([]string{"alias1"})
+	res, err := cmd.FindCmd([]string{"alias1"}, false)
 	if err != nil {
 		t.Fatal("finding alias should work")
 	}
 	assert.Equal(t, res.Name, "child1")
 
-	res, err = cmd.FindCmd([]string{"alias2"})
+	res, err = cmd.FindCmd([]string{"alias2"}, false)
 	if err != nil {
 		t.Fatal("finding alias should work")
 	}
 	assert.Equal(t, res.Name, "child1")
 
-	res, err = cmd.FindCmd([]string{"alias3"})
+	res, err = cmd.FindCmd([]string{"alias3"}, false)
+	if err == nil {
+		t.Fatal("should not find this child!")
+	}
+	assert.Nil(t, res)
+}
+
+func TestFindCmdPrefix(t *testing.T) {
+	cmd := newCmd("root", "")
+	cmd.AddCmd(newCmd("cmdone", ""))
+	cmd.AddCmd(newCmd("cmdtwo", ""))
+
+	res, err := cmd.FindCmd([]string{"cmdo"}, true)
+	if err != nil {
+		t.Fatal("finding should work")
+	}
+	assert.Equal(t, res.Name, "cmdone")
+
+	res, err = cmd.FindCmd([]string{"cmdt"}, true)
+	if err != nil {
+		t.Fatal("finding should work")
+	}
+	assert.Equal(t, res.Name, "cmdtwo")
+
+	res, err = cmd.FindCmd([]string{"c"}, true)
+	if err == nil {
+		t.Fatal("should not find this child!")
+	}
+	assert.Nil(t, res)
+
+	res, err = cmd.FindCmd([]string{"cmd"}, true)
 	if err == nil {
 		t.Fatal("should not find this child!")
 	}

completer.go

@@ -3,12 +3,13 @@ package ishell
 import (
 	"strings"
 
-	"github.com/flynn-archive/go-shlex"
+	shlex "github.com/flynn-archive/go-shlex"
 )
 
 type iCompleter struct {
-	cmd      *Cmd
-	disabled func() bool
+	cmd          *Cmd
+	disabled     func() bool
+	partialMatch bool
 }
 
 func (ic iCompleter) Do(line []rune, pos int) (newLine [][]rune, length int) {
@@ -45,7 +46,7 @@ func (ic iCompleter) Do(line []rune, pos int) (newLine [][]rune, length int) {
 }
 
 func (ic iCompleter) getWords(w []string) (s []string) {
-	cmd, args := ic.cmd.FindCmd(w)
+	cmd, args := ic.cmd.FindCmd(w, ic.partialMatch)
 	if cmd == nil {
 		cmd, args = ic.cmd, w
 	}

example/main.go

@@ -14,6 +14,9 @@ import (
 func main() {
 	shell := ishell.New()
 
+	// allow commands' partial match (prefix)
+	shell.PartialMatch(true)
+
 	// display info.
 	shell.Println("Sample Interactive Shell")
 

ishell.go

@@ -49,6 +49,7 @@ type Shell struct {
 	active            bool
 	activeMutex       sync.RWMutex
 	ignoreCase        bool
+	partialMatch      bool
 	customCompleter   bool
 	multiChoiceActive bool
 	haltChan          chan struct{}
@@ -265,7 +266,7 @@ func (s *Shell) handleCommand(str []string) (bool, error) {
 			str[i] = strings.ToLower(str[i])
 		}
 	}
-	cmd, args := s.rootCmd.FindCmd(str)
+	cmd, args := s.rootCmd.FindCmd(str, s.partialMatch)
 	if cmd == nil {
 		return false, nil
 	}
@@ -358,7 +359,14 @@ func (s *Shell) readMultiLinesFunc(f func(string) bool) (string, error) {
 }
 
 func (s *Shell) initCompleters() {
-	s.setCompleter(iCompleter{cmd: s.rootCmd, disabled: func() bool { return s.multiChoiceActive }})
+	ic := iCompleter{
+		cmd: s.rootCmd,
+		disabled: func() bool {
+			return s.multiChoiceActive
+		},
+		partialMatch: s.partialMatch,
+	}
+	s.setCompleter(ic)
 }
 
 func (s *Shell) setCompleter(completer readline.AutoCompleter) {
@@ -642,6 +650,13 @@ func (s *Shell) IgnoreCase(ignore bool) {
 	s.ignoreCase = ignore
 }
 
+// PartialMatch specifies whether commands should match partially.
+// Defaults to false i.e. commands must exactly match
+// If true, unique prefixes should match commands.
+func (s *Shell) PartialMatch(partialMatch bool) {
+	s.partialMatch = partialMatch
+}
+
 // ProgressBar returns the progress bar for the shell.
 func (s *Shell) ProgressBar() ProgressBar {
 	return s.progressBar