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 use strict;
   7 use warnings;
   8 package Devel::REPL::Plugin::ReadLineHistory;
   9
  10 our $VERSION = '1.003027';
  11
  12 use Devel::REPL::Plugin;
  13 use File::HomeDir;
  14 use File::Spec;
  15 use namespace::autoclean;
  16
  17 my $hist_file = $ENV{PERLREPL_HISTFILE} ||
  18     File::Spec->catfile(File::HomeDir->my_home, '.perlreplhist');
  19
  20 # HISTLEN should probably be in a config file to stop people accidentally
  21 # truncating their history if they start the program and forget to set
  22 # PERLREPL_HISTLEN
  23 my $hist_len=$ENV{PERLREPL_HISTLEN} || 100;
  24
  25 around 'run' => sub {
  26    my $orig=shift;
  27    my ($self, @args)=@_;
  28    if ($self->term->ReadLine eq 'Term::ReadLine::Gnu') {
  29       $self->term->stifle_history($hist_len);
  30    }
  31    if ($self->term->ReadLine eq 'Term::ReadLine::Perl') {
  32       $self->term->Attribs->{MaxHistorySize} = $hist_len;
  33    }
  34    if (-f($hist_file)) {
  35       if ($self->term->ReadLine eq 'Term::ReadLine::Gnu') {
  36          $self->term->ReadHistory($hist_file);
  37       }
  38       if ($self->term->ReadLine eq 'Term::ReadLine::Perl') {
  39          open HIST, $hist_file or die "ReadLineHistory: could not open $hist_file: $!\n";
  40          while (my $line = <HIST>) {
  41             chomp $line;
  42             $self->term->addhistory($line);
  43          }
  44          close HIST;
  45       }
  46    }
  47
  48    $self->term->Attribs->{do_expand}=1;  # for Term::ReadLine::Gnu
  49    $self->term->MinLine(2);              # don't save one letter commands
  50
  51    # let History plugin know we have Term::ReadLine support
  52    $self->have_readline_history(1) if $self->can('have_readline_history');
  53
  54
  55    $self->$orig(@args);
  56
  57    if ($self->term->ReadLine eq 'Term::ReadLine::Gnu') {
  58       $self->term->WriteHistory($hist_file) ||
  59       $self->print("warning: failed to write history file $hist_file");
  60    }
  61    if ($self->term->ReadLine eq 'Term::ReadLine::Perl') {
  62       my @lines = $self->term->GetHistory() if $self->term->can('GetHistory');
  63       if( open HIST, ">$hist_file" ) {
  64          print HIST join("\n",@lines);
  65          close HIST;
  66       } else {
  67          $self->print("warning: unable to WriteHistory to $hist_file");
  68       }
  69    }
  70 };
  71
  72 1;
  73
  74 __END__
  75
  76 =head1 NAME
  77
  78 Devel::REPL::Plugin::ReadLineHistory - Integrate history with the facilities provided by L<Term::ReadLine>
  79
  80 =head1 DESCRIPTION
  81
  82 This plugin enables loading and saving command line history from
  83 a file as well has history expansion of previous commands using
  84 the !-syntax a la bash.
  85
  86 By default, history expansion is enabled with this plugin when
  87 using L<Term::ReadLine::Gnu|Term::ReadLine::Gnu>. That means that
  88 "loose" '!' characters will be treated as history events which
  89 may not be what you wish.
  90
  91 To avoid this, you need to quote the '!' with '\':
  92
  93   my $var = "foo\!";
  94
  95 or place the arguments in single quotes---but enable the
  96 C<Term::ReadLine> attribute C<history_quotes_inhibit_expansion>:
  97
  98   $_REPL->term->Attribs->{history_quotes_inhibit_expansion} = 1;
  99   my $var = 'foo!';
 100
 101 and to disable history expansion from GNU readline/history do
 102
 103   $_REPL->term->Attribs->{do_expand} = 0;
 104
 105 =head1 CONFLICTS
 106
 107 Note that L<Term::ReadLine::Perl> does not support a history
 108 expansion method.  In that case, you may wish to use the
 109 L<Devel::REPL History plugin|Devel::REPL::Plugin::History> which provides similar functions.
 110 Work is underway to make use of either L<History|Devel::REPL::Plugin::History> or
 111 L<ReadLineHistory|Devel::REPL::Plugin::ReadHistory>> consistent for expansion with either the
 112 L<Term::ReadLine::Gnu> support or L<Term::ReadLine::Perl>.
 113
 114 =cut
 115