Unable to exit REPL via escape codes when TERM=dumb #29111

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1. silverwind

   added

   replIssues and PRs related to the REPL subsystem.Issues and PRs related to the REPL subsystem.

   on Aug 13, 2019
2. bnoordhuis commented on Aug 13, 2019

   

   bnoordhuis

   on Aug 13, 2019

   Member

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   I don't think it's unexpected: the terminfo entry for 'dumb' basically says it doesn't support anything except ^G (bel).

   On the other hand, lib/readline.js has some emulation baked in and teaching it about ^D isn't hard:

   diff --git a/lib/readline.js b/lib/readline.js
   index b741557a4d..1e7047ce1d 100644
   --- a/lib/readline.js
   +++ b/lib/readline.js
   @@ -825,6 +825,9 @@ function _ttyWriteDumb(s, key) {
        }
      }
    
   +  if (key.ctrl && key.name === 'd')
   +    this.close();
   +
      switch (key.name) {
        case 'return':  // Carriage return, i.e. \r
          this._sawReturnAt = Date.now();

   The reason ^C doesn't work is because the first ^C leaves a \x03 character (the C in ^C) in the command buffer and that trips up this logic:
   

   node/lib/repl.js

   Lines 633 to 638 in 427e534

   	const empty = self.line.length === 0;
   	self.clearLine();
   	_turnOffEditorMode(self);
   	const cmd = self[kBufferedCommandSymbol];
   	if (!(cmd && cmd.length > 0) && empty) {
3. cjihrig commented on Aug 14, 2019

   

   cjihrig

   on Aug 14, 2019

   Contributor

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   This change in _ttyWriteDumb() fixes the Control+C issue. I'm not sure if it's correct.

   diff --git a/lib/readline.js b/lib/readline.js
   index b741557a4d..0606b63585 100644
   --- a/lib/readline.js
   +++ b/lib/readline.js
   @@ -823,6 +823,8 @@ function _ttyWriteDumb(s, key) {
          // This readline instance is finished
          this.close();
        }
   +
   +    return;
      }
    
      switch (key.name) {

   And, like Ben mentioned, the code doesn't currently support Control+D. It looks like it was never added in the original PR.
4. legendecas commented on Aug 14, 2019

   

   legendecas

   on Aug 14, 2019

   Last edited by legendecas

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   Control+D would trigger end of stdin stream in most terminal, which has handled by readline.
5. cjihrig

   added 2 commits that reference this issue on Aug 17, 2019

   readline: close dumb terminals on Control+C

   ...

   a5edcee

   readline: close dumb terminals on Control+D

   ...

   93b341e
6. cjihrig

   closed this as completedin a5edceeon Aug 17, 2019