Improve diagnosis if caff can't read answers from STDIN

[pgp-tools.git] / caff / caff

diff --git a/caff/caff b/caff/caff
index 302bf60c8dbcccd10696f39d8a59ced03b81dacd..866af1919956fc271ddb86dc45418e4089aaef92 100755 (executable)
--- a/caff/caff
+++ b/caff/caff
@@ -448,8 +448,9 @@ sub readwrite_gpg($$$$$%) {
 sub ask($$;$$) {
        my ($question, $default, $forceyes, $forceno) = @_;
        my $answer;
+       my $yn = $default ? '[Y/n]' : '[y/N]';
        while (1) {
-               print $question,' ',($default ? '[Y/n]' : '[y/N]'), ' ';
+               print $question,' ',$yn, ' ';
                if ($forceyes && $forceno) {
                        print "$default (from config/command line)\n";
                        return $default;
@@ -464,9 +465,17 @@ sub ask($$;$$) {
                };
 
                $answer = <STDIN>;
+               if (!defined $answer) {
+                       $OUTPUT_AUTOFLUSH = 1;
+                       die "\n\n".
+                           "End of STDIN reached.  Are you using xargs?  Caff wants to read from STDIN,\n".
+                           "so you can't really use it with xargs.  A patch against caff to read from\n".
+                           "the terminal would be apprechiated.\n".
+                           "For now instead of   cat keys | xargs caff  do  caff `cat keys`\n";
+               };
                chomp $answer;
-               last if ((defined $answer) && (length $answer <= 1));
-               print "grrrrrr.\n";
+               last if ((length $answer == 0) || ($answer =~ m/^[yYnN]$/) );
+               print "What about $yn is so hard to understand?\nAnswer with either 'n' or 'y' or just press enter for the default.\n";
                sleep 1;
        };
        my $result = $default;