85 lines
1.9 KiB
Go
85 lines
1.9 KiB
Go
// wrappedreadline is a package that has helpers for interacting with
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// readline from a panicwrap executable.
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//
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// panicwrap overrides the standard file descriptors so that the child process
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// no longer looks like a TTY. The helpers here access the extra file descriptors
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// passed by panicwrap to fix that.
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package wrappedreadline
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import (
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"os"
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"runtime"
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"github.com/chzyer/readline"
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)
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// These are the file descriptor numbers for the original stdin, stdout, stderr
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// streams from the parent process.
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const (
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StdinFd = 3
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StdoutFd = 4
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StderrFd = 5
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)
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// These are the *os.File values for the standard streams.
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var (
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Stdin = os.NewFile(uintptr(StdinFd), "stdin")
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Stdout = os.NewFile(uintptr(StdoutFd), "stdout")
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Stderr = os.NewFile(uintptr(StderrFd), "stderr")
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)
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// Override overrides the values in readline.Config that need to be
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// set with wrapped values.
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func Override(cfg *readline.Config) *readline.Config {
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cfg.Stdin = Stdin
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cfg.Stdout = Stdout
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cfg.Stderr = Stderr
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cfg.FuncGetWidth = TerminalWidth
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cfg.FuncIsTerminal = IsTerminal
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var rm RawMode
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cfg.FuncMakeRaw = rm.Enter
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cfg.FuncExitRaw = rm.Exit
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return cfg
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}
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// IsTerminal determines if this process is attached to a TTY.
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func IsTerminal() bool {
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// Windows is always a terminal
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if runtime.GOOS == "windows" {
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return true
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}
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// Same implementation as readline but with our custom fds
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return readline.IsTerminal(StdinFd) && (readline.IsTerminal(StdoutFd) || readline.IsTerminal(StderrFd))
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}
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// TerminalWidth gets the terminal width in characters.
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func TerminalWidth() int {
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if runtime.GOOS == "windows" {
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return readline.GetScreenWidth()
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}
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return getWidth()
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}
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// RawMode is a helper for entering and exiting raw mode.
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type RawMode struct {
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state *readline.State
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}
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func (r *RawMode) Enter() (err error) {
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r.state, err = readline.MakeRaw(StdinFd)
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return err
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}
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func (r *RawMode) Exit() error {
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if r.state == nil {
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return nil
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}
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return readline.Restore(StdinFd, r.state)
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}
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