use strict; 

opendir(DIR, "./") or die $!;  # open current directory
my @files;
while (my $file = readdir(DIR)) {
	# Use a regular expression to ignore files beginning with a period
	push(@files, lc($file));
}
closedir(DIR);

# read the prompt.
my $promptfile = shift;
print STDERR "reading $promptfile\n";

open(PROMPT, $promptfile);
my $i = 0;
while (my $prompt = <PROMPT>) { 
	$i++;
	print STDERR $prompt . "\n";
	$prompt =~ s/^\d+\.\s//; # remove "93. ";
	$prompt = lc($prompt);
	
	# concat a list of .wav files corresponding to the prompt
	my $files = "";
	foreach my $word (split(/\s+/, $prompt)) {
		# choose a random file from the files, that beings with the given $word.
		my @grepped = grep(/^$word/, @files);
		my $file = $grepped[ int(rand(scalar @grepped)) ]; # choose a random file
		$files .= $file . " ";
	}
	my $output = sprintf("S%05d",$i);
	my $command = "sox $files $output.wav";
	print STDERR $command . "\n"; # TODO: add system call.
	system($command);
	print STDOUT "$output.wav $output.mfc\n";
}
close(PROMPT);

##</code><code>##

Use of uninitialized value $file in concatenation (.) or string at scripts/conca
tprompt.pl line 29, <PROMPT> line 100.
sox           S00100.wav
sox FAIL sox: Not enough input filenames specified

##</code><code>##

perl -w scripts/concatprompt.pl trainprompts > codetrain.scp