| // Copyright 2018 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // This file contains a driver.UI implementation |
| // that provides the readline functionality if possible. |
| |
| //go:build (darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || windows) && !appengine && !android |
| |
| package main |
| |
| import ( |
| "fmt" |
| "io" |
| "os" |
| "strings" |
| |
| "github.com/google/pprof/driver" |
| "golang.org/x/term" |
| ) |
| |
| func init() { |
| newUI = newReadlineUI |
| } |
| |
| // readlineUI implements driver.UI interface using the |
| // golang.org/x/term package. |
| // The upstream pprof command implements the same functionality |
| // using the github.com/chzyer/readline package. |
| type readlineUI struct { |
| term *term.Terminal |
| } |
| |
| func newReadlineUI() driver.UI { |
| // disable readline UI in dumb terminal. (golang.org/issue/26254) |
| if v := strings.ToLower(os.Getenv("TERM")); v == "" || v == "dumb" { |
| return nil |
| } |
| // test if we can use term.ReadLine |
| // that assumes operation in the raw mode. |
| oldState, err := term.MakeRaw(0) |
| if err != nil { |
| return nil |
| } |
| term.Restore(0, oldState) |
| |
| rw := struct { |
| io.Reader |
| io.Writer |
| }{os.Stdin, os.Stderr} |
| return &readlineUI{term: term.NewTerminal(rw, "")} |
| } |
| |
| // Read returns a line of text (a command) read from the user. |
| // prompt is printed before reading the command. |
| func (r *readlineUI) ReadLine(prompt string) (string, error) { |
| r.term.SetPrompt(prompt) |
| |
| // skip error checking because we tested it |
| // when creating this readlineUI initially. |
| oldState, _ := term.MakeRaw(0) |
| defer term.Restore(0, oldState) |
| |
| s, err := r.term.ReadLine() |
| return s, err |
| } |
| |
| // Print shows a message to the user. |
| // It formats the text as fmt.Print would and adds a final \n if not already present. |
| // For line-based UI, Print writes to standard error. |
| // (Standard output is reserved for report data.) |
| func (r *readlineUI) Print(args ...interface{}) { |
| r.print(false, args...) |
| } |
| |
| // PrintErr shows an error message to the user. |
| // It formats the text as fmt.Print would and adds a final \n if not already present. |
| // For line-based UI, PrintErr writes to standard error. |
| func (r *readlineUI) PrintErr(args ...interface{}) { |
| r.print(true, args...) |
| } |
| |
| func (r *readlineUI) print(withColor bool, args ...interface{}) { |
| text := fmt.Sprint(args...) |
| if !strings.HasSuffix(text, "\n") { |
| text += "\n" |
| } |
| if withColor { |
| text = colorize(text) |
| } |
| fmt.Fprint(r.term, text) |
| } |
| |
| // colorize prints the msg in red using ANSI color escapes. |
| func colorize(msg string) string { |
| const red = 31 |
| var colorEscape = fmt.Sprintf("\033[0;%dm", red) |
| var colorResetEscape = "\033[0m" |
| return colorEscape + msg + colorResetEscape |
| } |
| |
| // IsTerminal reports whether the UI is known to be tied to an |
| // interactive terminal (as opposed to being redirected to a file). |
| func (r *readlineUI) IsTerminal() bool { |
| const stdout = 1 |
| return term.IsTerminal(stdout) |
| } |
| |
| // WantBrowser indicates whether browser should be opened with the -http option. |
| func (r *readlineUI) WantBrowser() bool { |
| return r.IsTerminal() |
| } |
| |
| // SetAutoComplete instructs the UI to call complete(cmd) to obtain |
| // the auto-completion of cmd, if the UI supports auto-completion at all. |
| func (r *readlineUI) SetAutoComplete(complete func(string) string) { |
| // TODO: Implement auto-completion support. |
| } |