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1 | =head1 NAME |
2 | |
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3 | Term::ReadLine - Perl interface to various C<readline> packages. |
4 | If no real package is found, substitutes stubs instead of basic functions. |
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5 | |
6 | =head1 SYNOPSIS |
7 | |
8 | use Term::ReadLine; |
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9 | my $term = new Term::ReadLine 'Simple Perl calc'; |
10 | my $prompt = "Enter your arithmetic expression: "; |
11 | my $OUT = $term->OUT || \*STDOUT; |
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12 | while ( defined ($_ = $term->readline($prompt)) ) { |
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13 | my $res = eval($_); |
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14 | warn $@ if $@; |
15 | print $OUT $res, "\n" unless $@; |
16 | $term->addhistory($_) if /\S/; |
17 | } |
18 | |
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19 | =head1 DESCRIPTION |
20 | |
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21 | This package is just a front end to some other packages. It's a stub to |
22 | set up a common interface to the various ReadLine implementations found on |
23 | CPAN (under the C<Term::ReadLine::*> namespace). |
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24 | |
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25 | =head1 Minimal set of supported functions |
26 | |
27 | All the supported functions should be called as methods, i.e., either as |
28 | |
29 | $term = new Term::ReadLine 'name'; |
30 | |
31 | or as |
32 | |
33 | $term->addhistory('row'); |
34 | |
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35 | where $term is a return value of Term::ReadLine-E<gt>new(). |
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36 | |
37 | =over 12 |
38 | |
39 | =item C<ReadLine> |
40 | |
41 | returns the actual package that executes the commands. Among possible |
42 | values are C<Term::ReadLine::Gnu>, C<Term::ReadLine::Perl>, |
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43 | C<Term::ReadLine::Stub>. |
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44 | |
45 | =item C<new> |
46 | |
47 | returns the handle for subsequent calls to following |
48 | functions. Argument is the name of the application. Optionally can be |
49 | followed by two arguments for C<IN> and C<OUT> filehandles. These |
50 | arguments should be globs. |
51 | |
52 | =item C<readline> |
53 | |
54 | gets an input line, I<possibly> with actual C<readline> |
55 | support. Trailing newline is removed. Returns C<undef> on C<EOF>. |
56 | |
57 | =item C<addhistory> |
58 | |
59 | adds the line to the history of input, from where it can be used if |
60 | the actual C<readline> is present. |
61 | |
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62 | =item C<IN>, C<OUT> |
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63 | |
64 | return the filehandles for input and output or C<undef> if C<readline> |
65 | input and output cannot be used for Perl. |
66 | |
67 | =item C<MinLine> |
68 | |
69 | If argument is specified, it is an advice on minimal size of line to |
70 | be included into history. C<undef> means do not include anything into |
71 | history. Returns the old value. |
72 | |
73 | =item C<findConsole> |
74 | |
75 | returns an array with two strings that give most appropriate names for |
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76 | files for input and output using conventions C<"E<lt>$in">, C<"E<gt>out">. |
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77 | |
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78 | =item Attribs |
79 | |
80 | returns a reference to a hash which describes internal configuration |
81 | of the package. Names of keys in this hash conform to standard |
82 | conventions with the leading C<rl_> stripped. |
83 | |
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84 | =item C<Features> |
85 | |
86 | Returns a reference to a hash with keys being features present in |
87 | current implementation. Several optional features are used in the |
88 | minimal interface: C<appname> should be present if the first argument |
89 | to C<new> is recognized, and C<minline> should be present if |
90 | C<MinLine> method is not dummy. C<autohistory> should be present if |
91 | lines are put into history automatically (maybe subject to |
92 | C<MinLine>), and C<addhistory> if C<addhistory> method is not dummy. |
93 | |
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94 | If C<Features> method reports a feature C<attribs> as present, the |
95 | method C<Attribs> is not dummy. |
96 | |
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97 | =back |
98 | |
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99 | =head1 Additional supported functions |
100 | |
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101 | Actually C<Term::ReadLine> can use some other package, that will |
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102 | support a richer set of commands. |
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103 | |
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104 | All these commands are callable via method interface and have names |
105 | which conform to standard conventions with the leading C<rl_> stripped. |
106 | |
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107 | The stub package included with the perl distribution allows some |
108 | additional methods: |
109 | |
110 | =over 12 |
111 | |
112 | =item C<tkRunning> |
113 | |
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114 | makes Tk event loop run when waiting for user input (i.e., during |
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115 | C<readline> method). |
116 | |
117 | =item C<ornaments> |
118 | |
119 | makes the command line stand out by using termcap data. The argument |
120 | to C<ornaments> should be 0, 1, or a string of a form |
121 | C<"aa,bb,cc,dd">. Four components of this string should be names of |
122 | I<terminal capacities>, first two will be issued to make the prompt |
123 | standout, last two to make the input line standout. |
124 | |
125 | =item C<newTTY> |
126 | |
127 | takes two arguments which are input filehandle and output filehandle. |
128 | Switches to use these filehandles. |
129 | |
130 | =back |
131 | |
132 | One can check whether the currently loaded ReadLine package supports |
133 | these methods by checking for corresponding C<Features>. |
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134 | |
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135 | =head1 EXPORTS |
136 | |
137 | None |
138 | |
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139 | =head1 ENVIRONMENT |
140 | |
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141 | The environment variable C<PERL_RL> governs which ReadLine clone is |
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142 | loaded. If the value is false, a dummy interface is used. If the value |
143 | is true, it should be tail of the name of the package to use, such as |
144 | C<Perl> or C<Gnu>. |
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145 | |
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146 | As a special case, if the value of this variable is space-separated, |
147 | the tail might be used to disable the ornaments by setting the tail to |
148 | be C<o=0> or C<ornaments=0>. The head should be as described above, say |
149 | |
150 | If the variable is not set, or if the head of space-separated list is |
151 | empty, the best available package is loaded. |
152 | |
153 | export "PERL_RL=Perl o=0" # Use Perl ReadLine without ornaments |
154 | export "PERL_RL= o=0" # Use best available ReadLine without ornaments |
155 | |
156 | (Note that processing of C<PERL_RL> for ornaments is in the discretion of the |
157 | particular used C<Term::ReadLine::*> package). |
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158 | |
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159 | =head1 CAVEATS |
160 | |
161 | It seems that using Term::ReadLine from Emacs minibuffer doesn't work |
162 | quite right and one will get an error message like |
163 | |
164 | Cannot open /dev/tty for read at ... |
165 | |
166 | One possible workaround for this is to explicitly open /dev/tty like this |
167 | |
168 | open (FH, "/dev/tty" ) |
169 | or eval 'sub Term::ReadLine::findConsole { ("&STDIN", "&STDERR") }'; |
170 | die $@ if $@; |
171 | close (FH); |
172 | |
173 | or you can try using the 4-argument form of Term::ReadLine->new(). |
174 | |
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175 | =cut |
176 | |
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177 | use strict; |
178 | |
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179 | package Term::ReadLine::Stub; |
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180 | our @ISA = qw'Term::ReadLine::Tk Term::ReadLine::TermCap'; |
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181 | |
182 | $DB::emacs = $DB::emacs; # To peacify -w |
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183 | our @rl_term_set; |
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184 | *rl_term_set = \@Term::ReadLine::TermCap::rl_term_set; |
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185 | |
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186 | sub PERL_UNICODE_STDIN () { 0x0001 } |
187 | |
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188 | sub ReadLine {'Term::ReadLine::Stub'} |
189 | sub readline { |
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190 | my $self = shift; |
191 | my ($in,$out,$str) = @$self; |
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192 | my $prompt = shift; |
193 | print $out $rl_term_set[0], $prompt, $rl_term_set[1], $rl_term_set[2]; |
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194 | $self->register_Tk |
195 | if not $Term::ReadLine::registered and $Term::ReadLine::toloop |
196 | and defined &Tk::DoOneEvent; |
197 | #$str = scalar <$in>; |
198 | $str = $self->get_line; |
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199 | $str =~ s/^\s*\Q$prompt\E// if ($^O eq 'MacOS'); |
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200 | utf8::upgrade($str) |
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201 | if (${^UNICODE} & PERL_UNICODE_STDIN || defined ${^ENCODING}) && |
202 | utf8::valid($str); |
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203 | print $out $rl_term_set[3]; |
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204 | # bug in 5.000: chomping empty string creats length -1: |
205 | chomp $str if defined $str; |
206 | $str; |
207 | } |
208 | sub addhistory {} |
209 | |
210 | sub findConsole { |
211 | my $console; |
212 | |
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213 | if ($^O eq 'MacOS') { |
214 | $console = "Dev:Console"; |
215 | } elsif (-e "/dev/tty") { |
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216 | $console = "/dev/tty"; |
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217 | } elsif (-e "con" or $^O eq 'MSWin32') { |
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218 | $console = "con"; |
219 | } else { |
220 | $console = "sys\$command"; |
221 | } |
222 | |
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223 | if (($^O eq 'amigaos') || ($^O eq 'beos') || ($^O eq 'epoc')) { |
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224 | $console = undef; |
225 | } |
226 | elsif ($^O eq 'os2') { |
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227 | if ($DB::emacs) { |
228 | $console = undef; |
229 | } else { |
230 | $console = "/dev/con"; |
231 | } |
232 | } |
233 | |
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234 | my $consoleOUT = $console; |
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235 | $console = "&STDIN" unless defined $console; |
236 | if (!defined $consoleOUT) { |
237 | $consoleOUT = defined fileno(STDERR) ? "&STDERR" : "&STDOUT"; |
238 | } |
239 | ($console,$consoleOUT); |
240 | } |
241 | |
242 | sub new { |
243 | die "method new called with wrong number of arguments" |
244 | unless @_==2 or @_==4; |
245 | #local (*FIN, *FOUT); |
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246 | my ($FIN, $FOUT, $ret); |
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247 | if (@_==2) { |
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248 | my($console, $consoleOUT) = $_[0]->findConsole; |
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249 | |
250 | open(FIN, "<$console"); |
251 | open(FOUT,">$consoleOUT"); |
252 | #OUT->autoflush(1); # Conflicts with debugger? |
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253 | my $sel = select(FOUT); |
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254 | $| = 1; # for DB::OUT |
255 | select($sel); |
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256 | $ret = bless [\*FIN, \*FOUT]; |
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257 | } else { # Filehandles supplied |
258 | $FIN = $_[2]; $FOUT = $_[3]; |
259 | #OUT->autoflush(1); # Conflicts with debugger? |
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260 | my $sel = select($FOUT); |
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261 | $| = 1; # for DB::OUT |
262 | select($sel); |
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263 | $ret = bless [$FIN, $FOUT]; |
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264 | } |
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265 | if ($ret->Features->{ornaments} |
266 | and not ($ENV{PERL_RL} and $ENV{PERL_RL} =~ /\bo\w*=0/)) { |
267 | local $Term::ReadLine::termcap_nowarn = 1; |
268 | $ret->ornaments(1); |
269 | } |
270 | return $ret; |
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271 | } |
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272 | |
273 | sub newTTY { |
274 | my ($self, $in, $out) = @_; |
275 | $self->[0] = $in; |
276 | $self->[1] = $out; |
277 | my $sel = select($out); |
278 | $| = 1; # for DB::OUT |
279 | select($sel); |
280 | } |
281 | |
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282 | sub IN { shift->[0] } |
283 | sub OUT { shift->[1] } |
284 | sub MinLine { undef } |
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285 | sub Attribs { {} } |
286 | |
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287 | my %features = (tkRunning => 1, ornaments => 1, 'newTTY' => 1); |
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288 | sub Features { \%features } |
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289 | |
290 | package Term::ReadLine; # So late to allow the above code be defined? |
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291 | |
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292 | our $VERSION = '1.01'; |
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293 | |
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294 | my ($which) = exists $ENV{PERL_RL} ? split /\s+/, $ENV{PERL_RL} : undef; |
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295 | if ($which) { |
296 | if ($which =~ /\bgnu\b/i){ |
297 | eval "use Term::ReadLine::Gnu;"; |
298 | } elsif ($which =~ /\bperl\b/i) { |
299 | eval "use Term::ReadLine::Perl;"; |
300 | } else { |
301 | eval "use Term::ReadLine::$which;"; |
302 | } |
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303 | } elsif (defined $which and $which ne '') { # Defined but false |
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304 | # Do nothing fancy |
305 | } else { |
306 | eval "use Term::ReadLine::Gnu; 1" or eval "use Term::ReadLine::Perl; 1"; |
307 | } |
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308 | |
309 | #require FileHandle; |
310 | |
311 | # To make possible switch off RL in debugger: (Not needed, work done |
312 | # in debugger). |
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313 | our @ISA; |
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314 | if (defined &Term::ReadLine::Gnu::readline) { |
315 | @ISA = qw(Term::ReadLine::Gnu Term::ReadLine::Stub); |
316 | } elsif (defined &Term::ReadLine::Perl::readline) { |
317 | @ISA = qw(Term::ReadLine::Perl Term::ReadLine::Stub); |
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318 | } elsif (defined $which && defined &{"Term::ReadLine::$which\::readline"}) { |
319 | @ISA = "Term::ReadLine::$which"; |
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320 | } else { |
321 | @ISA = qw(Term::ReadLine::Stub); |
322 | } |
323 | |
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324 | package Term::ReadLine::TermCap; |
325 | |
326 | # Prompt-start, prompt-end, command-line-start, command-line-end |
327 | # -- zero-width beautifies to emit around prompt and the command line. |
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328 | our @rl_term_set = ("","","",""); |
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329 | # string encoded: |
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330 | our $rl_term_set = ',,,'; |
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331 | |
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332 | our $terminal; |
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333 | sub LoadTermCap { |
334 | return if defined $terminal; |
335 | |
336 | require Term::Cap; |
337 | $terminal = Tgetent Term::Cap ({OSPEED => 9600}); # Avoid warning. |
338 | } |
339 | |
340 | sub ornaments { |
341 | shift; |
342 | return $rl_term_set unless @_; |
343 | $rl_term_set = shift; |
344 | $rl_term_set ||= ',,,'; |
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345 | $rl_term_set = 'us,ue,md,me' if $rl_term_set eq '1'; |
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346 | my @ts = split /,/, $rl_term_set, 4; |
347 | eval { LoadTermCap }; |
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348 | unless (defined $terminal) { |
349 | warn("Cannot find termcap: $@\n") unless $Term::ReadLine::termcap_nowarn; |
350 | $rl_term_set = ',,,'; |
351 | return; |
352 | } |
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353 | @rl_term_set = map {$_ ? $terminal->Tputs($_,1) || '' : ''} @ts; |
354 | return $rl_term_set; |
355 | } |
356 | |
357 | |
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358 | package Term::ReadLine::Tk; |
359 | |
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360 | our($count_handle, $count_DoOne, $count_loop); |
a737e074 |
361 | $count_handle = $count_DoOne = $count_loop = 0; |
362 | |
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363 | our($giveup); |
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364 | sub handle {$giveup = 1; $count_handle++} |
365 | |
366 | sub Tk_loop { |
367 | # Tk->tkwait('variable',\$giveup); # needs Widget |
368 | $count_DoOne++, Tk::DoOneEvent(0) until $giveup; |
369 | $count_loop++; |
370 | $giveup = 0; |
371 | } |
372 | |
373 | sub register_Tk { |
374 | my $self = shift; |
375 | $Term::ReadLine::registered++ |
376 | or Tk->fileevent($self->IN,'readable',\&handle); |
377 | } |
378 | |
379 | sub tkRunning { |
380 | $Term::ReadLine::toloop = $_[1] if @_ > 1; |
381 | $Term::ReadLine::toloop; |
382 | } |
383 | |
384 | sub get_c { |
385 | my $self = shift; |
386 | $self->Tk_loop if $Term::ReadLine::toloop && defined &Tk::DoOneEvent; |
387 | return getc $self->IN; |
388 | } |
389 | |
390 | sub get_line { |
391 | my $self = shift; |
392 | $self->Tk_loop if $Term::ReadLine::toloop && defined &Tk::DoOneEvent; |
393 | my $in = $self->IN; |
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394 | local ($/) = "\n"; |
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395 | return scalar <$in>; |
396 | } |
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397 | |
398 | 1; |
399 | |