package Tcl; use Carp; $Tcl::VERSION = '0.89'; $Tcl::STACK_TRACE = 1; =head1 NAME Tcl - Tcl extension module for Perl =head1 SYNOPSIS use Tcl; $interp = new Tcl; $interp->Eval('puts "Hello world"'); =head1 DESCRIPTION The Tcl extension module gives access to the Tcl library with functionality and interface similar to the C functions of Tcl. In other words, you can =over 8 =item create Tcl interpreters The Tcl interpreters so created are Perl objects whose destructors delete the interpreters cleanly when appropriate. =item execute Tcl code in an interpreter The code can come from strings, files or Perl filehandles. =item bind in new Tcl procedures The new procedures can be either C code (with addresses presumably obtained using I<dl_open> and I<dl_find_symbol>) or Perl subroutines (by name, reference or as anonymous subs). The (optional) deleteProc callback in the latter case is another perl subroutine which is called when the command is explicitly deleted by name or else when the destructor for the interpreter object is explicitly or implicitly called. =item Manipulate the result field of a Tcl interpreter =item Set and get values of variables in a Tcl interpreter =item Tie perl variables to variables in a Tcl interpreter The variables can be either scalars or hashes. =back =head2 Methods in class Tcl To create a new Tcl interpreter, use $i = new Tcl; The following methods and routines can then be used on the Perl object returned (the object argument omitted in each case). =over 8 =item Init () Invoke I<Tcl_Init> on the interpeter. =item Eval (STRING, FLAGS) Evaluate script STRING in the interpreter. If the script returns successfully (TCL_OK) then the Perl return value corresponds to Tcl interpreter's result otherwise a I<die> exception is raised with the $@ variable corresponding to Tcl's interpreter result object. In each case, I<corresponds> means that if the method is called in scalar context then the string result is returned but if the method is called in list context then the result is split as a Tcl list and returned as a Perl list. The FLAGS field is optional and can be a bitwise OR of the constants Tcl::EVAL_GLOBAL or Tcl::EVAL_DIRECT. =item GlobalEval (STRING) REMOVED. Evalulate script STRING at global level. Call I<Eval>(STRING, Tcl::EVAL_GLOBAL) instead. =item EvalFile (FILENAME) Evaluate the contents of the file with name FILENAME. Otherwise, the same as I<Eval>() above. =item EvalFileHandle (FILEHANDLE) Evaluate the contents of the Perl filehandle FILEHANDLE. Otherwise, the same as I<Eval>() above. Useful when using the filehandle DATA to tack on a Tcl script following an __END__ token. =item call (PROC, ARG, ...) Looks up procedure PROC in the interpreter and invokes it using Tcl's eval semantics that does command tracing and will use the ::unknown (AUTOLOAD) mechanism. The arguments (ARG, ...) are not passed through the Tcl parser. For example, spaces embedded in any ARG will not cause it to be split into two Tcl arguments before being passed to PROC. Before invoking procedure PROC special processing is performed on ARG list: 1. All subroutine references within ARG will be substituted with Tcl name which is responsible to invoke this subroutine. This Tcl name will be created using CreateCommand subroutine (see below). 2. All references to scalars will be substituted with names of Tcl variables transformed appropriately. These first two items allows to write and expect it to work properly such code as: my $r = 'aaaa'; button(".d", -textvariable => \$r, -command=>sub {$r++}); 3. As a special case, there is a mechanism to deal with Tk's special event variables (they are mentioned as '%x', '%y' and so on throughout Tcl). When creating a subroutine reference that uses such variables, you must declare the desired variables using Tcl::Ev as the first argument to the subroutine. Example: sub textPaste { my ($x,$y,$w) = @_; widget($w)->insert("\@$x,$y", $interp->Eval('selection get')); } $widget->bind('<2>', [\&textPaste, Tcl::Ev('%x', '%y'), $widget] ); =item return_ref (NAME) returns a reference corresponding to NAME, which was associated during previously called C<< $int->call(...) >> preprocessing. As a typical example this could be variable associated with a widget. =item delete_ref (NAME) deletes and returns a reference corresponding to NAME, which was associated during previously called C<< $int->call(...) >> preprocessing. =item icall (PROC, ARG, ...) Looks up procedure PROC in the interpreter and invokes it using Tcl's eval semantics that does command tracing and will use the ::unknown (AUTOLOAD) mechanism. The arguments (ARG, ...) are not passed through the Tcl parser. For example, spaces embedded in any ARG will not cause it to be split into two Tcl arguments before being passed to PROC. This is the lower-level procedure that the 'call' method uses. Arguments are converted efficiently from Perl SVs to Tcl_Objs. A Perl AV array becomes a Tcl_ListObj, an SvIV becomes a Tcl_IntObj, etc. The reverse conversion is done to the result. =item invoke (PROC, ARG, ...) Looks up procedure PROC in the interpreter and invokes it directly with arguments (ARG, ...) without passing through the Tcl parser. For example, spaces embedded in any ARG will not cause it to be split into two Tcl arguments before being passed to PROC. This differs from icall/call in that it directly invokes the command name without allowing for command tracing or making use of Tcl's unknown (AUTOLOAD) mechanism. If the command does not already exist in the interpreter, and error will be thrown. Arguments are converted efficiently from Perl SVs to Tcl_Objs. A Perl AV array becomes a Tcl_ListObj, an SvIV becomes a Tcl_IntObj, etc. The reverse conversion is done to the result. =item Tcl::Ev (FIELD, ...) Used to declare %-substitution variables of interest to a subroutine callback. FIELD is expected to be of the form "%#" where # is a single character, and multiple fields may be specified. Returns a blessed object that the 'call' method will recognize when it is passed as the first argument to a subroutine in a callback. See description of 'call' method for details. =item result () Returns the current Tcl interpreter result. List v. scalar context is handled as in I<Eval>() above. =item CreateCommand (CMDNAME, CMDPROC, CLIENTDATA, DELETEPROC) Binds a new procedure named CMDNAME into the interpreter. The CLIENTDATA and DELETEPROC arguments are optional. There are two cases: (1) CMDPROC is the address of a C function (presumably obtained using I<dl_open> and I<dl_find_symbol>. In this case CLIENTDATA and DELETEPROC are taken to be raw data of the ClientData and deleteProc field presumably obtained in a similar way. (2) CMDPROC is a Perl subroutine (either a sub name, a sub reference or an anonymous sub). In this case CLIENTDATA can be any perl scalar (e.g. a ref to some other data) and DELETEPROC must be a perl sub too. When CMDNAME is invoked in the Tcl interpeter, the arguments passed to the Perl sub CMDPROC are (CLIENTDATA, INTERP, LIST) where INTERP is a Perl object for the Tcl interpreter which called out and LIST is a Perl list of the arguments CMDNAME was called with. As usual in Tcl, the first element of the list is CMDNAME itself. When CMDNAME is deleted from the interpreter (either explicitly with I<DeleteCommand> or because the destructor for the interpeter object is called), it is passed the single argument CLIENTDATA. =item DeleteCommand (CMDNAME) Deletes command CMDNAME from the interpreter. If the command was created with a DELETEPROC (see I<CreateCommand> above), then it is invoked at this point. When a Tcl interpreter object is destroyed either explicitly or implicitly, an implicit I<DeleteCommand> happens on all its currently registered commands. =item SetResult (STRING) Sets Tcl interpreter result to STRING. =item AppendResult (LIST) Appends each element of LIST to Tcl's interpreter result object. =item AppendElement (STRING) Appends STRING to Tcl interpreter result object as an extra Tcl list element. =item ResetResult () Resets Tcl interpreter result. =item SplitList (STRING) Splits STRING as a Tcl list. Returns a Perl list or the empty list if there was an error (i.e. STRING was not a properly formed Tcl list). In the latter case, the error message is left in Tcl's interpreter result object. =item SetVar (VARNAME, VALUE, FLAGS) The FLAGS field is optional. Sets Tcl variable VARNAME in the interpreter to VALUE. The FLAGS argument is the usual Tcl one and can be a bitwise OR of the constants Tcl::GLOBAL_ONLY, Tcl::LEAVE_ERR_MSG, Tcl::APPEND_VALUE, Tcl::LIST_ELEMENT. =item SetVar2 (VARNAME1, VARNAME2, VALUE, FLAGS) Sets the element VARNAME1(VARNAME2) of a Tcl array to VALUE. The optional argument FLAGS behaves as in I<SetVar> above. =item GetVar (VARNAME, FLAGS) Returns the value of Tcl variable VARNAME. The optional argument FLAGS behaves as in I<SetVar> above. =item GetVar2 (VARNAME1, VARNAME2, FLAGS) Returns the value of the element VARNAME1(VARNAME2) of a Tcl array. The optional argument FLAGS behaves as in I<SetVar> above. =item UnsetVar (VARNAME, FLAGS) Unsets Tcl variable VARNAME. The optional argument FLAGS behaves as in I<SetVar> above. =item UnsetVar2 (VARNAME1, VARNAME2, FLAGS) Unsets the element VARNAME1(VARNAME2) of a Tcl array. The optional argument FLAGS behaves as in I<SetVar> above. =back =head2 Linking Perl and Tcl variables You can I<tie> a Perl variable (scalar or hash) into class Tcl::Var so that changes to a Tcl variable automatically "change" the value of the Perl variable. In fact, as usual with Perl tied variables, its current value is just fetched from the Tcl variable when needed and setting the Perl variable triggers the setting of the Tcl variable. To tie a Perl scalar I<$scalar> to the Tcl variable I<tclscalar> in interpreter I<$interp> with optional flags I<$flags> (see I<SetVar> above), use tie $scalar, Tcl::Var, $interp, "tclscalar", $flags; Omit the I<$flags> argument if not wanted. To tie a Perl hash I<%hash> to the Tcl array variable I<array> in interpreter I<$interp> with optional flags I<$flags> (see I<SetVar> above), use tie %hash, Tcl::Var, $interp, "array", $flags; Omit the I<$flags> argument if not wanted. Any alteration to Perl variable I<$hash{"key"}> affects the Tcl variable I<array(key)> and I<vice versa>. =head2 Accessing Perl from within Tcl After creation of Tcl interpreter, in addition to evaluation of Tcl/Tk commands within Perl, other way round also instantiated. Within a special namespace C< ::perl > following objects are created: ::perl::Eval So it is possible to use Perl objects from within Tcl. =head2 Moving Tcl/Tk around with Tcl.pm NOTE: explanations below is for developers managing Tcl/Tk installations itself, users should skip this section. In order to create Tcl/Tk application with this module, you need to make sure that Tcl/Tk is available within visibility of this module. There are many ways to achieve this, varying on ease of starting things up and providing flexible moveable archived files. Following list enumerates them, in order of increased possibility to change location. =over =item * First method Install Tcl/Tk first, then install Perl module Tcl, so installed Tcl/Tk will be used. This is most normal approach, and no care of Tcl/Tk distribution is taken on Perl side (this is done on Tcl/Tk side) =item * Second method Copy installed Tcl/Tk binaries to some location, then install Perl module Tcl with a special action to make Tcl.pm know of this location. This approach makes sure that only chosen Tcl installation is used. =item * Third method During compiling Tcl Perl module, Tcl/Tk could be statically linked into module's shared library and all other files zipped into a single archive, so each file extracted when needed. =back Some global variables within $Tcl::config:: namespace are used to make such installations possible. =head3 First method =head3 Second method To use second approach, desired set of Tcl/Tk binaries should be prepared in a single directory. Mostly these files could be files from existing Tcl/Tk installation. Use C<create-moveable-dist.pl> script to create proper configuration this way. From inmplementation side of view, following things are done in this way: =over =item * Entire Tcl/Tk directory is copied into C<blib/lib> =item * Tcl.cfg file is created at the same dir where Tcl.pm is placed; this file contain some configuration and a code to initially load Tcl shared library. =back =head3 Third method To link Tcl/Tk binaries, prepare their libraries and then instruct Makefile.PL to use these libraries in a link stage. (TODO provide better detailed description) =head1 AUTHORS Malcolm Beattie, mbeattie@sable.ox.ac.uk, 23 Oct 1994. Vadim Konovalov, vkon@cpan.org, 19 May 2003. Jeff Hobbs, jeff (a) activestate . com, 22 Mar 2004. Gisle Aas, gisle (a) activestate . com, 14 Apr 2004. =head1 COPYRIGHT This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See http://www.perl.com/perl/misc/Artistic.html =cut use strict; use DynaLoader; use vars qw(@ISA); @ISA = qw(DynaLoader); # consideration for moveable configuration of tcl/tk # This is done before bootstraping, to make possible of searching of correct # shared libraries $Tcl::config::tcl_pm_path = [__FILE__=~/^(.*)Tcl\.pm$/i]->[0]; do "$Tcl::config::tcl_pm_path/Tcl.cfg" if -f "$Tcl::config::tcl_pm_path/Tcl.cfg"; our $DL_PATH; unless (defined $DL_PATH) { $DL_PATH = $ENV{PERL_TCL_DL_PATH} || $ENV{PERL_TCL_DLL} || ""; } unless ($DL_PATH) { require Config; for my $inc (@INC) { my $tkkit = "$inc/auto/Tcl/tkkit.$Config::Config{so}"; if (-f $tkkit) { $DL_PATH = $tkkit; last; } } } my $path; if ($^O eq 'darwin') { require Config; $path = "$Config::Config{binexp}:$ENV{PATH}"; } { local $ENV{PATH} = $path if $path; Tcl->bootstrap($Tcl::VERSION); } END { Tcl::_Finalize(); } #TODO make better wording here # %anon_refs keeps track of anonymous subroutines that were created with # "CreateComand" method during process of transformation of arguments for # "call" and other stuff such as scalar refs and so on. # (TODO -- find out how to check for refcounting and proper releasing of # resources) my %anon_refs; # %widget_refs is an array to hold refs that were created when working with # widget the point is - it's not dangerous to delete more than needed, because # those # will be re-created at the very next time they needed. # however when widget goes away, it is good to delete anything that comes # into mind with that widget my %widget_refs; my $current_widget = ''; sub _current_refs_widget {$current_widget=shift} # Subroutine "call" preprocess the arguments for special cases # and then calls "icall" (implemented in Tcl.xs), which invokes # the command in Tcl. sub call { my $interp = shift; my @args = @_; # Process arguments looking for special cases for (my $argcnt=0; $argcnt<=$#args; $argcnt++) { my $arg = $args[$argcnt]; my $ref = ref($arg); next unless $ref; if ($ref eq 'CODE') { # We have been passed something like \&subroutine # Create a proc in Tcl that invokes this subroutine (no args) $args[$argcnt] = $interp->create_tcl_sub($arg); $widget_refs{$current_widget}->{$args[$argcnt]}++; } elsif ($ref =~ /^Tcl::Tk::Widget\b/) { # We have been passed a widget reference. # Convert to its Tk pathname (eg, .top1.fr1.btn2) $args[$argcnt] = $arg->path; $current_widget = $args[$argcnt] if $argcnt==0; } elsif ($ref eq 'SCALAR') { # We have been passed something like \$scalar # Create a tied variable between Tcl and Perl. # stringify scalar ref, create in ::perl namespace on Tcl side # This will be SCALAR(0xXXXXXX) - leave it to become part of a # Tcl array. my $nm = "::perl::$arg"; #$nm =~ s/\W/_/g; # remove () from stringified name unless (exists $anon_refs{$nm}) { $widget_refs{$current_widget}->{$nm}++; $anon_refs{$nm} = $arg; my $s = $$arg; tie $$arg, 'Tcl::Var', $interp, $nm; $s = '' unless defined $s; $$arg = $s; } $args[$argcnt] = $nm; # ... and substitute its name } elsif ($ref eq 'ARRAY' && ref($arg->[0]) eq 'CODE') { # We have been passed something like [\&subroutine, $arg1, ...] # Create a proc in Tcl that invokes this subroutine with args my $events; # Look for Tcl::Ev objects as the first arg - these must be # passed through for Tcl to evaluate. Used primarily for %-subs # This could check for any arg ref being Tcl::Ev obj, but it # currently doesn't. if ($#$arg >= 1 && ref($arg->[1]) eq 'Tcl::Ev') { $events = splice(@$arg, 1, 1); } $args[$argcnt] = $interp->create_tcl_sub(sub { splice @_, 0, 3; # remove ClientData, Interp and CmdName $arg->[0]->(@_, @$arg[1..$#$arg]); }, $events); } elsif ($ref eq 'ARRAY' && ref($arg->[0]) =~ /^Tcl::Tk::Widget\b/) { # We have been passed [$Tcl_Tk_widget, 'method name', ...] # Create a proc in Tcl that invokes said method with args my $events; # Look for Tcl::Ev objects as the first arg - these must be # passed through for Tcl to evaluate. Used primarily for %-subs # This could check for any arg ref being Tcl::Ev obj, but it # currently doesn't. if ($#$arg >= 1 && ref($arg->[1]) eq 'Tcl::Ev') { $events = splice(@$arg, 1, 1); } my $wid = $arg->[0]; my $method_name = $arg->[1]; $args[$argcnt] = $interp->create_tcl_sub(sub { splice @_, 0, 3; # remove ClientData, Interp and CmdName $wid->$method_name(@$arg[2..$#$arg]); }, $events); } elsif (ref($arg) eq 'REF' and ref($$arg) eq 'SCALAR') { # this is a very special shortcut: if we see construct like \\"xy" # then place proper Tcl::Ev(...) for easier access my $events = [map {"%$_"} split '', $$$arg]; if (ref($args[$argcnt+1]) eq 'ARRAY' && ref($args[$argcnt+1]->[0]) eq 'CODE') { $arg = $args[$argcnt+1]; $args[$argcnt] = $interp->create_tcl_sub(sub { splice @_, 0, 3; # remove ClientData, Interp and CmdName $arg->[0]->(@_, @$arg[1..$#$arg]); }, $events); } elsif (ref($args[$argcnt+1]) eq 'CODE') { $args[$argcnt] = $interp->create_tcl_sub($args[$argcnt+1],$events); } else { warn "not CODE/ARRAY expected after description of event fields"; } splice @args, $argcnt+1, 1; } } # Done with special var processing. The only processing that icall # will do with the args is efficient conversion of SV to Tcl_Obj. # A SvIV will become a Tcl_IntObj, ARRAY refs will become Tcl_ListObjs, # and so on. The return result from icall will do the opposite, # converting a Tcl_Obj to an SV. if (!$Tcl::STACK_TRACE) { return $interp->icall(@args); } elsif (wantarray) { my @res; eval { @res = $interp->icall(@args); }; if ($@) { confess "Tcl error '$@' while invoking array result call:\n" . "\t\"@args\""; } return @res; } else { my $res; eval { $res = $interp->icall(@args); }; if ($@) { confess "Tcl error '$@' while invoking scalar result call:\n" . "\t\"@args\""; } return $res; } } # wcall is simple wrapper to 'call' but it tries to search $res in %anon_hash # This implementation is temporary sub wcall { if (wantarray) { return call(@_); } else { my $res = call(@_); if (exists $anon_refs{$res}) { return $anon_refs{$res}; } return $res; } } sub return_ref { my $interp = shift; my $rname = shift; return $anon_refs{$rname}; } sub delete_ref { my $interp = shift; my $rname = shift; my $ref = delete $anon_refs{$rname}; if (ref($ref) eq 'CODE') { $interp->DeleteCommand($rname); } else { $interp->UnsetVar($rname); #TODO: will this delete variable in Tcl? untie $$ref; } return $ref; } sub return_widget_refs { my $interp = shift; my $wpath = shift; return keys %{$widget_refs{$wpath}}; } sub delete_widget_refs { my $interp = shift; my $wpath = shift; for (keys %{$widget_refs{$wpath}}) { #print STDERR "del:$wpath($_)\n"; delete $widget_refs{$wpath}->{$_}; $interp->delete_ref($_); } } # create_tcl_sub will create TCL sub that will invoke perl anonymous sub # If $events variable is specified then special processing will be # performed to provide needed '%' variables. # If $tclname is specified then procedure will have namely that name, # otherwise it will have machine-readable name. # Returns tcl script suitable for using in tcl events. sub create_tcl_sub { my ($interp,$sub,$events,$tclname) = @_; unless ($tclname) { # stringify sub, becomes "CODE(0x######)" in ::perl namespace $tclname = "::perl::$sub"; } unless (exists $anon_refs{$tclname}) { $anon_refs{$tclname} = $sub; $interp->CreateCommand($tclname, $sub); } if ($events) { # Add any %-substitutions to callback $tclname = "$tclname " . join(' ', @{$events}); } return $tclname; } sub Ev { my @events = @_; return bless \@events, "Tcl::Ev"; } package Tcl::List; use overload '""' => \&as_string, fallback => 1; package Tcl::Var; sub TIESCALAR { my $class = shift; my @objdata = @_; Carp::croak 'Usage: tie $s, Tcl::Var, $interp, $varname [, $flags]' unless @_ == 2 || @_ == 3; bless \@objdata, $class; } sub TIEHASH { my $class = shift; my @objdata = @_; Carp::croak 'Usage: tie %hash, Tcl::Var, $interp, $varname [, $flags]' unless @_ == 2 || @_ == 3; bless \@objdata, $class; } my %arraystates; sub FIRSTKEY { my $obj = shift; die "STORE Usage: objdata @{$obj} $#{$obj}, not 2 or 3 (@_)" unless @{$obj} == 2 || @{$obj} == 3; my ($interp, $varname, $flags) = @$obj; $arraystates{$varname} = $interp->invoke("array","startsearch",$varname); my $r = $interp->invoke("array","nextelement",$varname,$arraystates{$varname}); if ($r eq '') { delete $arraystates{$varname}; return undef; } return $r; } sub NEXTKEY { my $obj = shift; die "STORE Usage: objdata @{$obj} $#{$obj}, not 2 or 3 (@_)" unless @{$obj} == 2 || @{$obj} == 3; my ($interp, $varname, $flags) = @$obj; my $r = $interp->invoke("array","nextelement",$varname,$arraystates{$varname}); if ($r eq '') { delete $arraystates{$varname}; return undef; } return $r; } sub CLEAR { my $obj = shift; die "STORE Usage: objdata @{$obj} $#{$obj}, not 2 or 3 (@_)" unless @{$obj} == 2 || @{$obj} == 3; my ($interp, $varname, $flags) = @$obj; $interp->invoke("array", "unset", "$varname"); #$interp->invoke("array", "set", "$varname", ""); } sub DELETE { my $obj = shift; Carp::croak "STORE Usage: objdata @{$obj} $#{$obj}, not 2 or 3 (@_)" unless @{$obj} == 2 || @{$obj} == 3; my ($interp, $varname, $flags) = @{$obj}; my ($str1) = @_; $interp->invoke("unset", "$varname($str1)"); # protect strings? } sub UNTIE { my $ref = shift; #print STDERR "UNTIE:$ref(@_)\n"; } sub DESTROY { my $ref = shift; delete $anon_refs{$ref->[1]}; } # This is the perl equiv to the C version, for reference # #sub STORE { # my $obj = shift; # Carp::croak "STORE Usage: objdata @{$obj} $#{$obj}, not 2 or 3 (@_)" # unless @{$obj} == 2 || @{$obj} == 3; # my ($interp, $varname, $flags) = @{$obj}; # my ($str1, $str2) = @_; # if ($str2) { # $interp->SetVar2($varname, $str1, $str2, $flags); # } else { # $interp->SetVar($varname, $str1, $flags || 0); # } #} # #sub FETCH { # my $obj = shift; # Carp::croak "FETCH Usage: objdata @{$obj} $#{$obj}, not 2 or 3 (@_)" # unless @{$obj} == 2 || @{$obj} == 3; # my ($interp, $varname, $flags) = @{$obj}; # my $key = shift; # if ($key) { # return $interp->GetVar2($varname, $key, $flags || 0); # } else { # return $interp->GetVar($varname, $flags || 0); # } #} 1; __END__