Re: New harness is failing things
[p5sagit/p5-mst-13.2.git] / lib / Term / ReadLine.pm
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cb31d310 1=head1 NAME
2
c07a80fd 3Term::ReadLine - Perl interface to various C<readline> packages. If
cb31d310 4no real package is found, substitutes stubs instead of basic functions.
5
6=head1 SYNOPSIS
7
8 use Term::ReadLine;
9 $term = new Term::ReadLine 'Simple Perl calc';
10 $prompt = "Enter your arithmetic expression: ";
11 $OUT = $term->OUT || STDOUT;
12 while ( defined ($_ = $term->readline($prompt)) ) {
13 $res = eval($_), "\n";
14 warn $@ if $@;
15 print $OUT $res, "\n" unless $@;
16 $term->addhistory($_) if /\S/;
17 }
18
c07a80fd 19=head1 DESCRIPTION
20
21This package is just a front end to some other packages. At the moment
22this description is written, the only such package is Term-ReadLine,
23available on CPAN near you. The real target of this stub package is to
24set up a common interface to whatever Readline emerges with time.
25
cb31d310 26=head1 Minimal set of supported functions
27
28All the supported functions should be called as methods, i.e., either as
29
30 $term = new Term::ReadLine 'name';
31
32or as
33
34 $term->addhistory('row');
35
1fef88e7 36where $term is a return value of Term::ReadLine-E<gt>Init.
cb31d310 37
38=over 12
39
40=item C<ReadLine>
41
42returns the actual package that executes the commands. Among possible
43values are C<Term::ReadLine::Gnu>, C<Term::ReadLine::Perl>,
44C<Term::ReadLine::Stub Exporter>.
45
46=item C<new>
47
48returns the handle for subsequent calls to following
49functions. Argument is the name of the application. Optionally can be
50followed by two arguments for C<IN> and C<OUT> filehandles. These
51arguments should be globs.
52
53=item C<readline>
54
55gets an input line, I<possibly> with actual C<readline>
56support. Trailing newline is removed. Returns C<undef> on C<EOF>.
57
58=item C<addhistory>
59
60adds the line to the history of input, from where it can be used if
61the actual C<readline> is present.
62
63=item C<IN>, $C<OUT>
64
65return the filehandles for input and output or C<undef> if C<readline>
66input and output cannot be used for Perl.
67
68=item C<MinLine>
69
70If argument is specified, it is an advice on minimal size of line to
71be included into history. C<undef> means do not include anything into
72history. Returns the old value.
73
74=item C<findConsole>
75
76returns an array with two strings that give most appropriate names for
1fef88e7 77files for input and output using conventions C<"E<lt>$in">, C<"E<gt>out">.
cb31d310 78
a737e074 79=item Attribs
80
81returns a reference to a hash which describes internal configuration
82of the package. Names of keys in this hash conform to standard
83conventions with the leading C<rl_> stripped.
84
cb31d310 85=item C<Features>
86
87Returns a reference to a hash with keys being features present in
88current implementation. Several optional features are used in the
89minimal interface: C<appname> should be present if the first argument
90to C<new> is recognized, and C<minline> should be present if
91C<MinLine> method is not dummy. C<autohistory> should be present if
92lines are put into history automatically (maybe subject to
93C<MinLine>), and C<addhistory> if C<addhistory> method is not dummy.
94
a737e074 95If C<Features> method reports a feature C<attribs> as present, the
96method C<Attribs> is not dummy.
97
cb31d310 98=back
99
a737e074 100=head1 Additional supported functions
101
cb31d310 102Actually C<Term::ReadLine> can use some other package, that will
103support reacher set of commands.
104
a737e074 105All these commands are callable via method interface and have names
106which conform to standard conventions with the leading C<rl_> stripped.
107
f36776d9 108The stub package included with the perl distribution allows some
109additional methods:
110
111=over 12
112
113=item C<tkRunning>
114
7a2e2cd6 115makes Tk event loop run when waiting for user input (i.e., during
f36776d9 116C<readline> method).
117
118=item C<ornaments>
119
120makes the command line stand out by using termcap data. The argument
121to C<ornaments> should be 0, 1, or a string of a form
122C<"aa,bb,cc,dd">. Four components of this string should be names of
123I<terminal capacities>, first two will be issued to make the prompt
124standout, last two to make the input line standout.
125
126=item C<newTTY>
127
128takes two arguments which are input filehandle and output filehandle.
129Switches to use these filehandles.
130
131=back
132
133One can check whether the currently loaded ReadLine package supports
134these methods by checking for corresponding C<Features>.
7a2e2cd6 135
cb31d310 136=head1 EXPORTS
137
138None
139
a737e074 140=head1 ENVIRONMENT
141
8dcee03e 142The environment variable C<PERL_RL> governs which ReadLine clone is
405ff068 143loaded. If the value is false, a dummy interface is used. If the value
144is true, it should be tail of the name of the package to use, such as
145C<Perl> or C<Gnu>.
a737e074 146
405ff068 147As a special case, if the value of this variable is space-separated,
148the tail might be used to disable the ornaments by setting the tail to
149be C<o=0> or C<ornaments=0>. The head should be as described above, say
150
151If the variable is not set, or if the head of space-separated list is
152empty, the best available package is loaded.
153
154 export "PERL_RL=Perl o=0" # Use Perl ReadLine without ornaments
155 export "PERL_RL= o=0" # Use best available ReadLine without ornaments
156
157(Note that processing of C<PERL_RL> for ornaments is in the discretion of the
158particular used C<Term::ReadLine::*> package).
a737e074 159
cb31d310 160=cut
161
162package Term::ReadLine::Stub;
7a2e2cd6 163@ISA = qw'Term::ReadLine::Tk Term::ReadLine::TermCap';
cb31d310 164
165$DB::emacs = $DB::emacs; # To peacify -w
7a2e2cd6 166*rl_term_set = \@Term::ReadLine::TermCap::rl_term_set;
cb31d310 167
168sub ReadLine {'Term::ReadLine::Stub'}
169sub readline {
a737e074 170 my $self = shift;
171 my ($in,$out,$str) = @$self;
6d697788 172 my $prompt = shift;
173 print $out $rl_term_set[0], $prompt, $rl_term_set[1], $rl_term_set[2];
a737e074 174 $self->register_Tk
175 if not $Term::ReadLine::registered and $Term::ReadLine::toloop
176 and defined &Tk::DoOneEvent;
177 #$str = scalar <$in>;
178 $str = $self->get_line;
6d697788 179 $str =~ s/^\s*\Q$prompt\E// if ($^O eq 'MacOS');
7a2e2cd6 180 print $out $rl_term_set[3];
cb31d310 181 # bug in 5.000: chomping empty string creats length -1:
182 chomp $str if defined $str;
183 $str;
184}
185sub addhistory {}
186
187sub findConsole {
188 my $console;
189
6d697788 190 if ($^O eq 'MacOS') {
191 $console = "Dev:Console";
192 } elsif (-e "/dev/tty") {
cb31d310 193 $console = "/dev/tty";
8878e869 194 } elsif (-e "con" or $^O eq 'MSWin32') {
cb31d310 195 $console = "con";
196 } else {
197 $console = "sys\$command";
198 }
199
4d2c4e07 200 if (($^O eq 'amigaos') || ($^O eq 'beos') || ($^O eq 'epoc')) {
287f63d2 201 $console = undef;
202 }
203 elsif ($^O eq 'os2') {
cb31d310 204 if ($DB::emacs) {
205 $console = undef;
206 } else {
207 $console = "/dev/con";
208 }
209 }
210
211 $consoleOUT = $console;
212 $console = "&STDIN" unless defined $console;
213 if (!defined $consoleOUT) {
214 $consoleOUT = defined fileno(STDERR) ? "&STDERR" : "&STDOUT";
215 }
216 ($console,$consoleOUT);
217}
218
219sub new {
220 die "method new called with wrong number of arguments"
221 unless @_==2 or @_==4;
222 #local (*FIN, *FOUT);
405ff068 223 my ($FIN, $FOUT, $ret);
cb31d310 224 if (@_==2) {
225 ($console, $consoleOUT) = findConsole;
226
227 open(FIN, "<$console");
228 open(FOUT,">$consoleOUT");
229 #OUT->autoflush(1); # Conflicts with debugger?
230 $sel = select(FOUT);
231 $| = 1; # for DB::OUT
232 select($sel);
405ff068 233 $ret = bless [\*FIN, \*FOUT];
cb31d310 234 } else { # Filehandles supplied
235 $FIN = $_[2]; $FOUT = $_[3];
236 #OUT->autoflush(1); # Conflicts with debugger?
237 $sel = select($FOUT);
238 $| = 1; # for DB::OUT
239 select($sel);
405ff068 240 $ret = bless [$FIN, $FOUT];
cb31d310 241 }
405ff068 242 if ($ret->Features->{ornaments}
243 and not ($ENV{PERL_RL} and $ENV{PERL_RL} =~ /\bo\w*=0/)) {
244 local $Term::ReadLine::termcap_nowarn = 1;
245 $ret->ornaments(1);
246 }
247 return $ret;
cb31d310 248}
f36776d9 249
250sub newTTY {
251 my ($self, $in, $out) = @_;
252 $self->[0] = $in;
253 $self->[1] = $out;
254 my $sel = select($out);
255 $| = 1; # for DB::OUT
256 select($sel);
257}
258
cb31d310 259sub IN { shift->[0] }
260sub OUT { shift->[1] }
261sub MinLine { undef }
a737e074 262sub Attribs { {} }
263
84902520 264my %features = (tkRunning => 1, ornaments => 1, 'newTTY' => 1);
a737e074 265sub Features { \%features }
cb31d310 266
267package Term::ReadLine; # So late to allow the above code be defined?
a737e074 268
405ff068 269my ($which) = exists $ENV{PERL_RL} ? split /\s+/, $ENV{PERL_RL} : undef;
a737e074 270if ($which) {
271 if ($which =~ /\bgnu\b/i){
272 eval "use Term::ReadLine::Gnu;";
273 } elsif ($which =~ /\bperl\b/i) {
274 eval "use Term::ReadLine::Perl;";
275 } else {
276 eval "use Term::ReadLine::$which;";
277 }
405ff068 278} elsif (defined $which and $which ne '') { # Defined but false
a737e074 279 # Do nothing fancy
280} else {
281 eval "use Term::ReadLine::Gnu; 1" or eval "use Term::ReadLine::Perl; 1";
282}
cb31d310 283
284#require FileHandle;
285
286# To make possible switch off RL in debugger: (Not needed, work done
287# in debugger).
288
289if (defined &Term::ReadLine::Gnu::readline) {
290 @ISA = qw(Term::ReadLine::Gnu Term::ReadLine::Stub);
291} elsif (defined &Term::ReadLine::Perl::readline) {
292 @ISA = qw(Term::ReadLine::Perl Term::ReadLine::Stub);
293} else {
294 @ISA = qw(Term::ReadLine::Stub);
295}
296
7a2e2cd6 297package Term::ReadLine::TermCap;
298
299# Prompt-start, prompt-end, command-line-start, command-line-end
300# -- zero-width beautifies to emit around prompt and the command line.
301@rl_term_set = ("","","","");
302# string encoded:
303$rl_term_set = ',,,';
304
305sub LoadTermCap {
306 return if defined $terminal;
307
308 require Term::Cap;
309 $terminal = Tgetent Term::Cap ({OSPEED => 9600}); # Avoid warning.
310}
311
312sub ornaments {
313 shift;
314 return $rl_term_set unless @_;
315 $rl_term_set = shift;
316 $rl_term_set ||= ',,,';
7b8d334a 317 $rl_term_set = 'us,ue,md,me' if $rl_term_set eq '1';
7a2e2cd6 318 my @ts = split /,/, $rl_term_set, 4;
319 eval { LoadTermCap };
405ff068 320 unless (defined $terminal) {
321 warn("Cannot find termcap: $@\n") unless $Term::ReadLine::termcap_nowarn;
322 $rl_term_set = ',,,';
323 return;
324 }
7a2e2cd6 325 @rl_term_set = map {$_ ? $terminal->Tputs($_,1) || '' : ''} @ts;
326 return $rl_term_set;
327}
328
329
a737e074 330package Term::ReadLine::Tk;
331
332$count_handle = $count_DoOne = $count_loop = 0;
333
334sub handle {$giveup = 1; $count_handle++}
335
336sub Tk_loop {
337 # Tk->tkwait('variable',\$giveup); # needs Widget
338 $count_DoOne++, Tk::DoOneEvent(0) until $giveup;
339 $count_loop++;
340 $giveup = 0;
341}
342
343sub register_Tk {
344 my $self = shift;
345 $Term::ReadLine::registered++
346 or Tk->fileevent($self->IN,'readable',\&handle);
347}
348
349sub tkRunning {
350 $Term::ReadLine::toloop = $_[1] if @_ > 1;
351 $Term::ReadLine::toloop;
352}
353
354sub get_c {
355 my $self = shift;
356 $self->Tk_loop if $Term::ReadLine::toloop && defined &Tk::DoOneEvent;
357 return getc $self->IN;
358}
359
360sub get_line {
361 my $self = shift;
362 $self->Tk_loop if $Term::ReadLine::toloop && defined &Tk::DoOneEvent;
363 my $in = $self->IN;
4e83e451 364 local ($/) = "\n";
a737e074 365 return scalar <$in>;
366}
cb31d310 367
3681;
369