You'll need to install one of them and according to Term::ReadLine doku's last paragraph set $ENV{PERL_RL}="Perl" prior² to use Term::ReadLine¹

As a side note: I had no problems yet just using Term::ReadLine::Gnu with tab completion.

¹) Term::ReadLine is kind of a wrapper module proxying to other Term::ReadLine:* modules

edit

update

²) since use happens very early in compilation you'll most likely need to set the ENV within a BEGIN block.

(That's for sure a silly interface, Term::ReadLine should have a config option for the importer.)

update

update

looking into the source revealed the following line as fall back if PERL_RL is not found in %ENV

  eval "use Term::ReadLine::Gnu; 1" or eval "use Term::ReadLine::Perl; 1";

This means Term::ReadLine::Perl is only used by default if Term::ReadLine::Gnu wasn't found! Since you are using a T::RL::Perl* only feature you MUST set the env.

Maybe check with print $term->ReadLine; which module was loaded

Thanks LanX
i'm still in the fog..

CPAN Terminal> l Term::ReadLine
..
Version Installed        1.14
Version on CPAN          1.14

CPAN Terminal> l Term::ReadLine::Perl
..
Version Installed        1.0303
Version on CPAN          1.0303

#anyway using Term::ReadLine::Perl directly cause some error:

io@COMP:C>perl -MTerm::ReadLine::Perl -e 0
Can't locate object method "Features" via package "Term::ReadLine::Stu
+b" at C:/ulisse/strawberry/perl/lib/Term/ReadLine
Perl.pm line 101.
Compilation failed in require.
BEGIN failed--compilation aborted.
[download]

Eventually, modifying the code to use the ENV var seems to produce the same results:

#!perl
use strict;
use warnings;
use Term::ReadLine;

BEGIN{$ENV{PERL_RL}="Perl"}
print "\$ENV{PERL_RL} $ENV{PERL_RL}\n";
$ENV{TERM}=undef;

my $term = Term::ReadLine->new('xxx');
print $term->ReadLine;
my %cmds = (a=>1,b=>2);

   # THIS WORKS &readline::rl_basic_commands(keys %cmds);
   # THE FOLLOWING CHECK DOES NOT WORK
   if (exists &readline::rl_basic_commands){print "BEFORE WHILE EXISTS
+\n"; &readline::rl_basic_commands(keys %cmds);}

while ( defined ( $_ = $term->readline( '>') ) ) {
     print "$_\n";
}
continue{
   # THIS CHECK WORKS INDEED!
   if (exists &readline::rl_basic_commands){print "IN CONTINUE EXISTS\
+n"; &readline::rl_basic_commands(keys %cmds);}
}


###OUTPUT
$ENV{PERL_RL} Perl

>
###if you press TAB the current dir content is dumped: this is the def
+ault behaviour if
###you does not provide autocompletion list

###but after, if you press ENTER:
>
Term::ReadLine::Perl
IN CONTINUE EXISTS

>
a b
>
[download]

That said, it seems to be an headache builder. Thanks for the suggestions.

L*

There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

I've posted working code (plz read again), build on this and you'll find your error. ( we are at a point were you should show more efforts ;-)

Beside of this, you are using an internal feature of Term::ReadLine::Perl while Term::ReadLine offers an official interface for all sub-modules.

I've tested it with the debugger setting env and either *::Gnu *::Perl and *::Zoid did tab-completion w/o problems.

Have a look at Attribs

Cheers Rolf

_{(addicted to the Perl Programming Language and ☆☆☆☆ :)}

this works for me after installing Term::ReadLine::Perl

perl -e'
BEGIN { $ENV{PERL_RL}="Perl" }
$\="\n";
use Term::ReadLine;
$term=Term::ReadLine->new("test");
print $term->ReadLine;
'

Term::ReadLine::Perl
[download]

But an exists on rl_basic_commands is very unreliable...

... which is not surprising after I noticed that Term::ReadLine::Perl has some AUTOLOAD and tie magic.

I didn't try to dig deeper into it, you might wanna try out Term::ReadLine::Perl5 or Term::ReadLine::Zoid (no guaranty)

No luck with T::RL::Perl5 too..


cpan> force install Term::ReadLine::Perl5
...
INST_VERSION 1.41

cpanp -i Win32::Console::ANSI  #needed by T::RL::Perl5

INST_VERSION 1.08


## i have no completion working with the changed lines about T::RL::Pe
+rl5

use Term::ReadLine::Perl5;

BEGIN{$ENV{PERL_RL}="Perl5"}
print "\$ENV{PERL_RL} $ENV{PERL_RL}\n";
$ENV{TERM}=undef;

my $term = Term::ReadLine::Perl5->new('xxx');
[download]

I think i need to stick with the less bogus behaviour.

Thanks L*

There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

Thanks LanX for not presenting the solution but sparse hints, seriously.

The best of such hints was: Have a look at Attribs.

My problem was that i was relaying on the function readline::rl_basic that, as explained by LanX, is used internally by Term::ReadLine::Perl and a strange behaviour (still obscure to me) happened: the code presented above seems to reveal that this function is not defined the first time we check for it but is defined in the continue block.
To overcomplicate things, win32 is strange and dumb as console (we need some hacks at it..).

The solution is to access $term->Attribs->{completion_function} and configure manually that feature. Here i present a working example to play with and that demonstrate what stated above.



#!perl
use strict;
use warnings;

BEGIN {
        # you can force Term::ReadLine to load the ::Perl
        # by setting the ENV PERL_RL variable
        # but you have to do it in a begin block
        # before the use statement
        # try to comment next line: probably ::Perl will be loaded
        # anyway if it is installed
        # try to set to a non available sub module
        # see details: https://metacpan.org/pod/Term::ReadLine#ENVIRON
+MENT
     $ENV{PERL_RL}="Perl";
        # on win32 systems it ENV TERM is 'dumb'
        # autocompletion is not possible.
        # try to comment next line on win32 and watch how does not wor
+k
        # see also http://bvr.github.io/2010/11/term-readline/
     $ENV{TERM} = 'not dumb' if $^O eq 'MSWin32';
}

use Term::ReadLine;
my $term=Term::ReadLine->new("test");

# Term::ReadLine is a wrapper module: it initilizes an Attribs hasref
# internally used to fill in the right configuration.
# You can use this hashref to set autompletion manually. As i did here
+.
#
# YOU MUST NOT USE readline::rl_basic_commands DIRECTLY!
#
# you cannot print anything from hashref returned by $term->Attribs
#foreach my $k (keys $term->Attribs){print "$k ${$term->Attribs}{$k}\n
+"}


my %cmd = (run1=>1, Rename1=>1, quit1=>1, QUONDAM1=>1);
my %alt = (run_2=>1,Rename_2=>1,quit_2=>1,QUONDAM_2=>1);
my $hr = \%cmd; # default hashref is a ref to %cmd

# first time initialization of autocompletion
&define_completion_func($hr);

print "The Term::ReadLine effective module loaded is: ",$term->ReadLin
+e,"\n";
print <<"END";
There are 2 sets of commands available:
    
  \%cmd        QUONDAM1  Rename1   quit1     run1
  \%alt        QUONDAM_2 Rename_2  quit_2    run_2
  
You can switch to alternates one entering 'alt'
and switch back with 'cmd'
TAB completion works and is set case insesitive
END

while ( defined ( $_ = $term->readline( 'prompt>') ) ) {
     /^$/ ? next : chomp;
     s/\s+//g;
     if    ($_ eq 'cmd'){ print "switching hashref to \%cmd\n"; $hr = 
+\%cmd }
     elsif ($_ eq 'alt'){ print "switching hashref to \%alt\n"; $hr = 
+\%alt }
     elsif (exists $$hr{$_} ) {print "OK $_ is defined in the current 
+hashref of commands\n"}
     else {next}
}
continue{ &define_completion_func($hr);}

sub define_completion_func {
    my $cur_hr = shift;
        # is time to access the $term->Attribs and set
        # the sub that will be used to do autocompletion
        # This version is case insensitive because of the i modifier
    $term->Attribs->{completion_function} = sub {
            my ($text, $line, $start) = @_;
            # uncomment next line to see debug stuff while you stress 
+autocomplete
            #print 'DEBUG: $text, $line, $start = >'.(join '< >',$text
+, $line, $start)."<\n";
            return grep { /^$text/i } sort keys %$cur_hr ;
    };
}
[download]


HtH
L*

There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

The docs for Term::ReadLine note that for attribute keys and imported methods, the rl_ prefix is stripped. Maybe you could try "basic_commands" instead of "rl_basic_commands"??