fix: add use_stdin option for just reading from stdin (#547)

docs/configuration.md

@@ -42,6 +42,7 @@
   - [`fail_text`](#fail_text)
   - [`stage_fixed`](#stage_fixed)
   - [`interactive`](#interactive)
+  - [`use_stdin`](#use_stdin)
 - [Script](#script)
   - [`runner`](#runner)
   - [`skip`](#skip)
@@ -51,6 +52,7 @@
   - [`fail_text`](#fail_text)
   - [`stage_fixed`](#stage_fixed)
   - [`interactive`](#interactive)
+  - [`use_stdin`](#use_stdin)
 - [Examples](#examples)
 - [More info](#more-info)
 
@@ -1045,7 +1047,14 @@ pre-commit:
 
 **Default: `false`**
 
-Whether to use interactive mode and provide a STDIN for a command or script.
+Whether to use interactive mode. This applies the certain behavior:
+- All `interactive` commands/scripts are executed after non-interactive.
+- When executing, lefthook tries to open /dev/tty (Linux/Unix only) and use it as stdin.
+- When [`no_tty`](#no_tty) option is set, `interactive` is ignored.
+
+**Note**
+
+If you want to pass stdin to your command or script but don't need to get the input from CLI, use [`use_stdin`](#use_stdin) option isntead.
 
 ## Script
 
@@ -1093,6 +1102,38 @@ commit-msg:
 
 When you try to commit `git commit -m "bad commit text"` script `template_checker` will be executed. Since commit text doesn't match the described pattern the commit process will be interrupted.
 
+### `use_stdin`
+
+Pass the stdin from the OS to the command/script.
+
+**Note**
+
+With many commands or scripts having `use_stdin: true`, only one will receive the data. The others will have nothing. If you need to pass the data from stdin to every command or script, please, submit a [feature request](https://github.com/evilmartians/lefthook/issues/new?assignees=&labels=feature+request&projects=&template=feature_request.md).
+
+**Example**
+
+Use this option for the `pre-push` hook when you have a script that does `while read ...`. Without this option lefthook will hang: lefthook uses [pseudo TTY](https://github.com/creack/pty) by default, and it doesn't close stdin when all data is read.
+
+```bash
+# .lefthook/pre-push/do-the-magic.sh
+
+remote="$1"
+url="$2"
+
+while read local_ref local_oid remote_ref remote_oid; do
+  # ...
+done
+```
+
+```yml
+# lefthook.yml
+pre-push:
+  scripts:
+    "do-the-magic.sh":
+      runner: bash
+      use_stdin: true
+```
+
 ### `runner`
 
 You should specify a runner for the script. This is a command that should execute a script file. It will be called the following way: `<runner> <path-to-script>` (e.g. `ruby .lefthook/pre-commit/lint.rb`).

docs/usage.md

@@ -19,6 +19,8 @@
   - [Concurrent files overrides](#concurrent-files-overrides)
   - [Capture ARGS from git in the script](#capture-args-from-git-in-the-script)
   - [Git LFS support](#git-lfs-support)
+  - [Pass stdin to a command or script](#pass-stdin-to-a-command-or-script)
+  - [Using an interactive command or script](#using-an-interactive-command-or-script)
 
 ----
 
@@ -304,3 +306,12 @@ Lefthook runs LFS hooks internally for the following hooks:
 - pre-push
 
 Errors are suppressed if git LFS is not required for the project. You can use [`LEFTHOOK_VERBOSE`](#lefthook_verbose) ENV to make lefthook show git LFS output.
+
+
+### Pass stdin to a command or script
+
+When you need to read the data from stdin – specify [`use_stdin: true`](./configuration.md#use_stdin). This option is good when you write a command or script that receives data from git using stdin (for the `pre-push` hook, for example).
+
+### Using an interactive command or script
+
+When you need to interact with user – specify [`interactive: true`](./configuration.md#interactive). Lefthook will connect to the current TTY and forward it to your command's or script's stdin.

internal/config/command.go

@@ -26,6 +26,7 @@ type Command struct {
 
 	FailText    string `mapstructure:"fail_text"   yaml:"fail_text,omitempty"   json:"fail_text,omitempty"   toml:"fail_text,omitempty"`
 	Interactive bool   `mapstructure:"interactive" yaml:",omitempty"            json:"interactive,omitempty" toml:"interactive,omitempty"`
+	UseStdin    bool   `mapstructure:"use_stdin"   yaml:",omitempty"            json:"use_stdin,omitempty"   toml:"use_stdin,omitempty"`
 	StageFixed  bool   `mapstructure:"stage_fixed" yaml:"stage_fixed,omitempty" json:"stage_fixed,omitempty" toml:"stage_fixed,omitempty"`
 }
 

internal/config/script.go

@@ -19,6 +19,7 @@ type Script struct {
 
 	FailText    string `mapstructure:"fail_text"   yaml:"fail_text,omitempty"   json:"fail_text,omitempty"   toml:"fail_text,omitempty"`
 	Interactive bool   `mapstructure:"interactive" yaml:",omitempty"            json:"interactive,omitempty" toml:"interactive,omitempty"`
+	UseStdin    bool   `mapstructure:"use_stdin"   yaml:",omitempty"            json:"use_stdin,omitempty"   toml:"use_stdin,omitempty"`
 	StageFixed  bool   `mapstructure:"stage_fixed" yaml:"stage_fixed,omitempty" json:"stage_fixed,omitempty" toml:"stage_fixed,omitempty"`
 }
 

internal/lefthook/run/exec/execute_unix.go

@@ -19,6 +19,14 @@ import (
 
 type CommandExecutor struct{}
 
+type executeArgs struct {
+	in                    io.Reader
+	out                   io.Writer
+	envs                  []string
+	root                  string
+	interactive, useStdin bool
+}
+
 func (e CommandExecutor) Execute(opts Options, out io.Writer) error {
 	in := os.Stdin
 	if opts.Interactive && !isatty.IsTerminal(os.Stdin.Fd()) {
@@ -40,10 +48,19 @@ func (e CommandExecutor) Execute(opts Options, out io.Writer) error {
 		)
 	}
 
+	args := &executeArgs{
+		in:          in,
+		out:         out,
+		envs:        envs,
+		root:        root,
+		interactive: opts.Interactive,
+		useStdin:    opts.UseStdin,
+	}
+
 	// We can have one command split into separate to fit into shell command max length.
 	// In this case we execute those commands one by one.
 	for _, command := range opts.Commands {
-		if err := e.executeOne(command, root, envs, opts.Interactive, in, out); err != nil {
+		if err := e.execute(command, args); err != nil {
 			return err
 		}
 	}
@@ -60,14 +77,14 @@ func (e CommandExecutor) RawExecute(command []string, out io.Writer) error {
 	return cmd.Run()
 }
 
-func (e CommandExecutor) executeOne(cmdstr string, root string, envs []string, interactive bool, in io.Reader, out io.Writer) error {
+func (e CommandExecutor) execute(cmdstr string, args *executeArgs) error {
 	command := exec.Command("sh", "-c", cmdstr)
-	command.Dir = root
-	command.Env = append(os.Environ(), envs...)
+	command.Dir = args.root
+	command.Env = append(os.Environ(), args.envs...)
 
-	if interactive {
-		command.Stdout = out
-		command.Stdin = in
+	if args.interactive || args.useStdin {
+		command.Stdout = args.out
+		command.Stdin = args.in
 		command.Stderr = os.Stderr
 		err := command.Start()
 		if err != nil {
@@ -81,9 +98,9 @@ func (e CommandExecutor) executeOne(cmdstr string, root string, envs []string, i
 
 		defer func() { _ = p.Close() }()
 
-		go func() { _, _ = io.Copy(p, in) }()
+		go func() { _, _ = io.Copy(p, args.in) }()
 
-		_, _ = io.Copy(out, p)
+		_, _ = io.Copy(args.out, p)
 	}
 
 	defer func() { _ = command.Process.Kill() }()

internal/lefthook/run/exec/execute_windows.go

@@ -11,6 +11,12 @@ import (
 )
 
 type CommandExecutor struct{}
+type executeArgs struct {
+	in   io.Reader
+	out  io.Writer
+	envs []string
+	root string
+}
 
 func (e CommandExecutor) Execute(opts Options, out io.Writer) error {
 	root, _ := filepath.Abs(opts.Root)
@@ -22,8 +28,15 @@ func (e CommandExecutor) Execute(opts Options, out io.Writer) error {
 		)
 	}
 
+	args := &executeArgs{
+		in:   os.Stdin,
+		out:  out,
+		envs: envs,
+		root: root,
+	}
+
 	for _, command := range opts.Commands {
-		if err := e.executeOne(command, root, envs, opts.Interactive, os.Stdin, out); err != nil {
+		if err := e.execute(command, args); err != nil {
 			return err
 		}
 	}
@@ -40,22 +53,17 @@ func (e CommandExecutor) RawExecute(command []string, out io.Writer) error {
 	return cmd.Run()
 }
 
-func (e CommandExecutor) executeOne(cmdstr string, root string, envs []string, interactive bool, in io.Reader, out io.Writer) error {
+func (e CommandExecutor) execute(cmdstr string, args *executeArgs) error {
 	cmdargs := strings.Split(cmdstr, " ")
 	command := exec.Command(cmdargs[0])
 	command.SysProcAttr = &syscall.SysProcAttr{
 		CmdLine: strings.Join(cmdargs, " "),
 	}
-	command.Dir = root
-	command.Env = append(os.Environ(), envs...)
-
-	if interactive {
-		command.Stdout = os.Stdout
-	} else {
-		command.Stdout = out
-	}
+	command.Dir = args.root
+	command.Env = append(os.Environ(), args.envs...)
 
-	command.Stdin = in
+	command.Stdout = args.out
+	command.Stdin = args.in
 	command.Stderr = os.Stderr
 	err := command.Start()
 	if err != nil {

internal/lefthook/run/exec/executor.go

@@ -6,10 +6,10 @@ import (
 
 // Options contains the data that controls the execution.
 type Options struct {
-	Name, Root, FailText string
-	Commands             []string
-	Env                  map[string]string
-	Interactive          bool
+	Name, Root, FailText  string
+	Commands              []string
+	Env                   map[string]string
+	Interactive, UseStdin bool
 }
 
 // Executor provides an interface for command execution.

internal/lefthook/run/runner.go

@@ -295,6 +295,7 @@ func (r *Runner) runScript(script *config.Script, path string, file os.FileInfo)
 		Commands:    []string{command},
 		FailText:    script.FailText,
 		Interactive: script.Interactive && !r.DisableTTY,
+		UseStdin:    script.UseStdin,
 		Env:         script.Env,
 	}, r.Hook.Follow)
 
@@ -374,6 +375,7 @@ func (r *Runner) runCommand(name string, command *config.Command) {
 		Commands:    run.commands,
 		FailText:    command.FailText,
 		Interactive: command.Interactive && !r.DisableTTY,
+		UseStdin:    command.UseStdin,
 		Env:         command.Env,
 	}, r.Hook.Follow)