Re: [Monotone-devel] MacOSX terminal does not allow me to enter passphrase

[Matthew A. Nicholson]

Nathaniel Smith wrote:
> On Fri, Oct 14, 2005 at 11:03:13PM +0200, Wim Oudshoorn wrote:
>
> > Not sure what is wrong, but the following monotone command gives me
> > troubles:
> >
> >   monotone cert 2c4 test-cert-1
> >
> > It shows on the terminal
> >
> >   monotone: expanded selector '2c4' -> 'i:2c4'
> >   monotone: expanding selection '2c4'
> >   monotone: expanded to '2c4681f8bef0783c5cb0e1be092fc93e58907dd4'
> >   *
> >
> > With the cursor shown at the * location.
> > If I press enter I the screen looks like:
> >
> >   monotone: expanded selector '2c4' -> 'i:2c4'
> >   monotone: expanding selection '2c4'
> >   monotone: expanded to '2c4681f8bef0783c5cb0e1be092fc93e58907dd4'
> >   
> >   enter passphrase for key ID address@hidden: 
> >   monotone: empty passphrase not allowed
> >   enter passphrase for key ID address@hidden: 
> >   monotone: empty passphrase not allowed
> >   enter passphrase for key ID address@hidden: 
> >   monotone: empty passphrase not allowed
> >   monotone: misuse: no passphrase given
> >   nelly:~/src/em-a woudshoo$ 
>
>
> Just looked at this again.  It seems to be a small, funky bug in
> monotone.
>
> If you pass only 2 arguments to 'cert', it reads stdin to get the
> actual contents of the cert.  It's not waiting for your password; it's
> waiting for stdin to report end-of-file (e.g., by you pressing ^D).
>
> However, I guess using 'cin' to read the contents of stdin is a bit of
> a problem, since I think istreams will never become valid to read
> after they have reported EOF, but the actual semantics of a tty
> are that it _can_ become readable again after reporting EOF?  I'm not
> quite sure what should be done here; even if we fix the problem so you
> can hit ^D and then enter your passphrase, a stdin-slurping interface
> that can only be used effectively when stdin is a tty is sort of
> pointless...

You can keep reading from an istream after an eof.  The attached sample 
program demonstrates this.  This is the meat of it all:

cin.clear()
cin >> data

You can also check for an EOF by doing cin.eof().

> [...]

--
Matthew A. Nicholson
Matt-Land.com

// cin EOF test

#include <iostream>
using namespace std;

int main(int argc, char** argv)
   {

   char c;
   while(cin >> c)
      cout << c;

   cout << "Checking for EOF\n";
   if(cin.eof())
      {
      cout << "Got EOF, continuing anyway\n";
      cin.clear();
      while(cin >> c)
         cout << c;
      }
   else
      {
      cout << "Reading failed for another reason, exiting\n";
      }

   return 0;
   }