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A Quick-and-dirty Script for “Direct Mode” in Perl

A Quick-and-dirty Script for “Direct Mode” in Perl

Ever get annoyed that there’s no “direct mode” environment in Perl? Instead, you have to save your code to a file and then execute it everytime. To offset this, I wrote this small program allows me to type and execute Perl code, complete statement by statement.

Here’s how to use it. Save the code to a file named ‘direct.pl’, and start it. When the “>” prompt shows, type (or copy & paste from notepad) your code. When you press enter, it will execute it, show the result, and wait for next line. This script is quick-and-dirty?meaning it’s not perfect and may not work every time but hey, that’s not the point. It will try to count and show the number of open brackets/braces/parenthesis for you, and will execute the statement only when you close them.

my $count = 0;my $statement = "";print "
> ";while (<>) {  chomp;  s/([^$\])#.*$/$1/;  while (/{|(|[/g) {$count++};  while (/}|)|]/g) {$count--};  $statement .= $_;  if (!$count) {    $_ = eval $statement;    print "
[$_]
";    if ($@) {print "Error: $@
"};    $statement = " ";    print "> ";  }  else {    print "$count> ";  }}
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