Proc::InvokeEditor - Perl extension for starting a text editor

  use Proc::InvokeEditor;
  my $edited_text = Proc::InvokeEditor->edit($unedited_text);

  my $result = Proc::InvokeEditor->edit($string);

  my @lines = Proc::InvokeEditor->edit(\@unedited_lines);

  my @lines = Proc::InvokeEditor->edit($string);

  my $editor = new Proc::InvokeEditor(editors => [ '/usr/bin/emacs' ]);
  $editor->cleanup(0);
  my $result = $editor->edit($string);

	my $reuslt = Proc::InvokeEditor->edit($string, '.xml');

package Proc::InvokeEditor;

use strict;
use warnings;

use File::Temp qw(tempfile);
use File::Spec;
use Carp::Assert;
use Fcntl;
File::Temp->safe_level( File::Temp::HIGH );

require Exporter;

use vars qw(@ISA %EXPORT_TAGS @EXPORT_OK @EXPORT $VERSION
            @DEFAULT_EDITORS);

@ISA = qw(Exporter);

# Items to export into callers namespace by default. Note: do not export
# names by default without a very good reason. Use EXPORT_OK instead.
# Do not simply export all your public functions/methods/constants.

# This allows declaration	use Proc::InvokeEditor ':all';
# If you do not need this, moving things directly into @EXPORT or @EXPORT_OK
# will save memory.
%EXPORT_TAGS = ( 'all' => [ qw(
	
) ] );

@EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );

@EXPORT = qw(
	
);
$VERSION = '1.06';

@DEFAULT_EDITORS = ( $ENV{'VISUAL'}, $ENV{'EDITOR'}, '/usr/bin/vi',
                     '/bin/vi', '/bin/ed'
);

sub new {
  my $proto = shift;
  my $class = ref($proto) || $proto;
  my $self = {
                'editors' => \@DEFAULT_EDITORS,
                'cleanup' => 1,
                'keep_file' => 0,
  };
  croak("$class requires an even number of parameters") if @_ % 2;
  my %args = @_;
  foreach my $param (qw(editors cleanup keep_file)) {
    if ($args{$param}) {
      $self->{$param} = $args{$param};
    }
  }
  bless ($self, $class);
  return $self;
}

sub editors {
  my $self = shift;
  my $editors = shift;
  if (defined $editors) {
    assert(ref($editors) eq 'ARRAY');
    $self->{'editors'} = $editors;
  }
  return $self->{'editors'};
}

sub editors_prepend {
  my $self = shift;
  my $edit = shift;
  assert(ref($edit) eq 'ARRAY');
  my @editors = @{$self->{'editors'}};
  unshift @editors, @$edit;
  $self->{'editors'} = \@editors;
}

sub editors_env {
  my $self = shift;
  my $edit = shift;
  assert(ref($edit) eq 'ARRAY');
  my @editors;
  if (@$edit) {
    foreach my $e (@$edit) {
      if (exists $ENV{$e} and defined $ENV{$e}) {
        push @editors, $ENV{$e};  
      }
    }
    my @editors_list = @{$self->{'editors'}};
    unshift @editors_list, @editors;
    $self->{'editors'} = \@editors_list;
  }
  return $self->{'editors'};
}

sub cleanup {
  my $self = shift;
  my $cleanup = shift;
  $self->{'cleanup'} = $cleanup if defined $cleanup;
  return $self->{'cleanup'};
}

sub keep_file {
  my $self = shift;
  my $keep_file = shift;
  $self->{'keep_file'} = $keep_file if defined $keep_file;
  return $self->{'keep_file'};
}

sub edit {
  my $self = shift;
  my $arg = shift;
  my $suff = shift;
  # if the argument supplied is a reference to an array of lines,
  # join it together based on the input record separator
  if (ref($arg) eq 'ARRAY') {
    $arg = join $/, @$arg;
  }
  my $result;
  if (ref($self)) {
    ($result, $self->{'filename'}) = _edit(
      $arg,
      $self->{'editors'},
      $self->{'cleanup'},
      $self->{'keep_file'},
      $self->{'filename'},
      $suff,
    );
  } else {
    ($result) = _edit($arg, \@DEFAULT_EDITORS, 1, 0, undef, $suff);
  }
  if (wantarray) {
    my @result = split m|$/|, $result;
    return @result;
  } else {
    return $result;
  }
}

sub first_usable {
  my $self = shift;
  my $er = shift;
  my @editors;
  if (defined $er) {
    @editors = @$er;
  } else {
    if (ref $self) {
      @editors = @{$self->{'editors'}};
    } else {
      @editors = @DEFAULT_EDITORS;
    }
  }

  my $chosen_editor;
  my @path = File::Spec->path;
  EDITORS: foreach my $editor (@editors) {
    next unless defined $editor;
    my @editor_bits = split /\s+/, $editor;
    next unless defined $editor_bits[0];
    if (File::Spec->file_name_is_absolute($editor_bits[0])
        and -x $editor_bits[0]) {
      $chosen_editor = \@editor_bits;
      last;
    } else {
      foreach my $dir (@path) {
         my $file = File::Spec->catfile($dir, $editor_bits[0]);
         if (-x $file) { 
           $editor_bits[0] = $file;
           $chosen_editor = \@editor_bits;
           last EDITORS;
         }
      }
    }
  }
  die "Couldn't find an editor: $!" unless defined $chosen_editor;

  return $chosen_editor;
}

sub _edit {
  my $string = shift;
  my $er = shift;
  my $unlink = shift;
  my $keep_file = shift;
  my $filename = shift;
  my $suff = shift;

  assert(ref($er) eq 'ARRAY');
  assert(defined $unlink);
  my @editors = @$er; 
  # Find an editor

  my $chosen_editor = first_usable(undef, $er); 

  my @suff;
  @suff = (SUFFIX => $suff) if $suff;

  # get a temp file, and write the text to it
  if (defined($filename) && $keep_file) {
    open my $fh, '>', $filename or die "Couldn't open tempfile [$filename]; $!";
    print $fh $string;
    close $fh or die "Couldn't close tempfile [$filename]; $!";
  }
  else {
    my $fh;
    ($fh, $filename) = tempfile(UNLINK => $unlink, @suff);
    print $fh $string;
    close $fh or die "Couldn't close tempfile [$filename]; $!";
  }
  # start the editor
  my $rc = system @$chosen_editor, $filename;
  # check what happened - die if it all went wrong.
  unless ($rc == 0) {
    my ($exit_value, $signal_num, $dumped_core);
    $exit_value = $? >> 8;
    $signal_num = $? & 127;
    $dumped_core = $? & 128;
    die "Error in editor - exit val = $exit_value, signal = $signal_num, coredump? = $dumped_core: $!";
  }

  # read the temp file
  sysopen(FH, $filename, O_RDONLY) or die "Couldn't sysopen $filename: $!";
  my $result;
  { local $/; $result = <FH>; }
  close FH or die "Couldn't close [$filename]: $!";
  # return as string
  if ($keep_file) {
    return ($result, $filename);
  }
  else {
    return ($result);
  }
}

1;
__END__