lib/Devel/REPL/Plugin/ReadLineHistory.pm

   1 # First cut at using the readline history directly rather than reimplementing
   2 # it. It does save history but it's a little crappy; still playing with it ;)
   3 #
   4 # epitaph, 22nd April 2007
   5
   6 package Devel::REPL::Plugin::ReadLineHistory;
   7
   8 use Devel::REPL::Plugin;
   9 use File::HomeDir;
  10 use File::Spec;
  11
  12 my $hist_file = $ENV{PERLREPL_HISTFILE} ||
  13     File::Spec->catfile(File::HomeDir->my_home, '.perlreplhist');
  14
  15 # HISTLEN should probably be in a config file to stop people accidentally
  16 # truncating their history if they start the program and forget to set
  17 # PERLREPL_HISTLEN
  18 my $hist_len=$ENV{PERLREPL_HISTLEN} || 100;
  19
  20 around 'run' => sub {
  21    my $orig=shift;
  22    my ($self, @args)=@_;
  23    if ($self->term->ReadLine eq 'Term::ReadLine::Gnu') {
  24       $self->term->stifle_history($hist_len);
  25    }
  26    if ($self->term->ReadLine eq 'Term::ReadLine::Perl') {
  27       $self->term->Attribs->{MaxHistorySize} = $hist_len;
  28    }
  29    if (-f($hist_file)) {
  30       if ($self->term->ReadLine eq 'Term::ReadLine::Gnu') {
  31          $self->term->ReadHistory($hist_file);
  32       }
  33       if ($self->term->ReadLine eq 'Term::ReadLine::Perl') {
  34          open HIST, $hist_file or die "ReadLineHistory: could not open $hist_file: $!\n";
  35          while (my $line = <HIST>) {
  36             chomp $line;
  37             $self->term->addhistory($line);
  38          }
  39          close HIST;
  40       }
  41    }
  42    $self->term->Attribs->{do_expand}=1;
  43    $self->$orig(@args);
  44    if ($self->term->ReadLine eq 'Term::ReadLine::Gnu') {
  45       $self->term->WriteHistory($hist_file) ||
  46       $self->print("warning: failed to write history file $hist_file");
  47    }
  48    if ($self->term->ReadLine eq 'Term::ReadLine::Perl') {
  49       my @lines = $self->term->GetHistory() if $self->term->can('GetHistory');
  50       if( open HIST, ">$hist_file" ) {
  51          print HIST join("\n",@lines);
  52          close HIST;
  53       } else {
  54          $self->print("warning: unable to WriteHistory to $hist_file");
  55       }
  56    }
  57 };
  58
  59 1;
  60
  61 __END__
  62
  63 =head1 NAME
  64
  65 Devel::REPL::Plugin::ReadLineHistory - Integrate history with the facilities provided by L<Term::ReadLine>
  66
  67 =head1 DESCRIPTION
  68
  69 This plugin enables loading and saving command line history from
  70 a file as well has history expansion of previous commands using
  71 the !-syntax a la bash.
  72
  73 By default, history expansion is enabled with this plugin when
  74 using L<Term::ReadLine::Gnu|Term::ReadLine::Gnu>. That means that
  75 "loose" '!' characters will be treated as history events which
  76 may not be what you wish.
  77
  78 To avoid this, you need to quote the '!' with '\':
  79
  80   my $var = "foo\!";
  81
  82 or place the arguments in single quotes---but enable the
  83 C<Term::ReadLine> attribute C<history_quotes_inhibit_expansion>:
  84
  85   $_REPL->term->Attribs->{history_quotes_inhibit_expansion} = 1;
  86   my $var = 'foo!';
  87
  88 and to disable history expansion from GNU readline/history do
  89
  90   $_REPL->term->Attribs->{do_expand} = 0;
  91
  92 =head1 CONFLICTS
  93
  94 Note that Term::ReadLine::Perl does not support a history
  95 expansion method.  In that case, you may wish to use the
  96 Devel::REPL History plugin which provides similar functions.
  97 Work is underway to make use of either History or
  98 ReadLineHistory consistent for expansion with either the
  99 Term::ReadLine::Gnu support or Term::ReadLine::Perl.
 100
 101 =cut
 102