I'm trying to write a shell like interface to manage some files, but I'm running into a problem when I'm trying to get fancy and use command completion. The problem is that using read(or sysread) you must press "Enter" before it starts reading from the buffer. I need it to run through the loop each time a character is typed. I tried using something like this

my ($buffer, $command);
while(read(STDIN, $buffer, 1)){
    #print "Read Character $buffer\n";
    if($buffer eq "\t"){
        ##Do command completion stuff
        last;
    }else{
        $command .= $buffer;
    }
}

if($command eq "this"){
  #Stuff
}elsif($command eq "this"){
  #More Stuff
}...
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Also if I can get this working, and I display the correct command, is there a way to put the command into STDIN, so that when they press "Enter" it will execute that command.