June 2018 Update

Task/Keyboard-input-Keypress-check/Perl/keyboard-input-keypress-check-1.pl

@@ -0,0 +1,12 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use Term::ReadKey;
+ReadMode 4;
+my $key;
+until(defined($key = ReadKey(-1))){
+	# anything
+	sleep 1;
+}
+print "got key '$key'\n";
+ReadMode('restore');

Task/Keyboard-input-Keypress-check/Perl/keyboard-input-keypress-check-2.pl

@@ -0,0 +1,50 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use Carp;
+use POSIX;
+use Term::ReadKey;
+$| = 1; # don't buffer; stdout is hot now
+
+#avoid creation of zombies
+sub _cleanup_and_die{
+	ReadMode('restore');
+	print "process $$ dying\n";
+	die;
+}
+sub _cleanup_and_exit{
+	ReadMode('restore');
+	print "process $$ exiting\n";
+	exit 1;
+}
+$SIG{'__DIE__'} = \&_cleanup_and_die;
+$SIG{'INT'}     = \&_cleanup_and_exit;
+$SIG{'KILL'}    = \&_cleanup_and_exit;
+$SIG{'TERM'}    = \&_cleanup_and_exit;
+$SIG{__WARN__}  = \&_warn;
+
+# fork into two processes:
+# child process is doing anything
+# parent process just listens to keyboard input
+my $pid = fork();
+if(not defined $pid){
+	print "error: resources not available.\n";
+	die "$!";
+}elsif($pid == 0){ # child
+	for(0..9){
+		print "doing something\n";
+		sleep 1;
+	}
+	exit 0;
+}else{ # parent
+	ReadMode('cbreak');
+	# wait until child has exited/died
+	while(waitpid($pid, POSIX::WNOHANG) == 0){
+		my $seq = ReadKey(-1);
+		if(defined $seq){
+			print "got key '$seq'\n";
+		}
+		sleep 1; # if ommitted, the cpu-load will reach up to 100%
+	}
+	ReadMode('restore');
+}