How to quote this parameter in perl module - perl

Question

I'm trying to use the AnyEvent::Twitter::Stream module and I want to reference a file that lists the Twitter uids I want to follow. I can put the uids in the code itself and it works as follows:
my $done = AnyEvent->condvar;
my $nt_filter = AnyEvent::Twitter::Stream->new(
username => $cf{account},
password => $cf{password},
method => 'filter',
follow => '15855509,14760150,18598536',
on_tweet => sub {
#some code.....
},
on_error => sub {
my $error = shift;
debug "ERROR: $error";
},
timeout => 45,
);
$done->recv;
But when I try to do the same using a file as such:
my $done = AnyEvent->condvar;
my $nt_filter = AnyEvent::Twitter::Stream->new(
open UID_FILE, "/tmp/uids" or die $!;
my #uid_line = <UID_FILE>;
username => $cf{account},
password => $cf{password},
method => 'filter',
follow => #uid_file,
on_tweet => sub {
#some code....
},
on_error => sub {
my $error = shift;
debug "ERROR: $error";
},
timeout => 45,
);
$done->recv;
it fails. The uids file has the following contents:
'15855509,14760150,18598536'
I'm getting a 406 error from Twitter, suggesting the format is not correct. I'm guessing the quotes are not correct somehow?

Answer 1

The AnyEvent::Twitter::Stream module subclasses AnyEvent and you don't need to access the base module at all. All the functionality is provided by the new method and the callbacks that you specify there, and you shouldn't call AnyEvent->condvar or $done->recv.
The open call and assignment to #uid_line don't belong inside the call to AnyEvent::Twitter::Stream->new.
Furthermore the variable you are using to supply the value for the follow parameter is #uid_file instead of #uid_line.
You must use strict; and use warnings; at the start of your programs, especially if you are asking for help with them. This will trap simple mistakes like this that you could otherwise overlook.
You can't in general use an array to supply a single scalar value. In this instance it may be OK as long as the file has only a single line (so there is only one element in the array) but there is a lot that could go wrong.
In addition you are passing single-quotes in the value that don't belong there: they appear in the code only to mark the start and end of the Perl string.
I suggest you read all decimal strings from your file like this
open my $uid_fh, '<', '/tmp/uids' or die $!;
my #uids;
push #uids, /\d+/g for <$uid_fh>;
(Note that these lines belong before the call to AnyEvent::Twitter::Stream->new)
Then you can supply the follow parameter by writing
follow => join(',', #uids),
I hope this is clear. Please ask again if you need further help.
Edit
These changes incorporated into your code should look like this, but it is incomplete and I cannot guarantee that it will work properly.
use strict;
use warnings;
use AnyEvent::Twitter::Stream;
open my $uid_fh, '<', '/tmp/uids' or die $!;
my #uids;
push #uids, /\d+/g for <$uid_fh>;
my %cf = (
account => 'myaccount',
password => 'password',
);
my $nt_filter = AnyEvent::Twitter::Stream->new(
username => $cf{account},
password => $cf{password},
method => 'filter',
follow => join(',', #uids),
on_tweet => sub {
#some code....
},
on_error => sub {
my $error = shift;
debug "ERROR: $error";
},
timeout => 45,
);

Answer 2

It looks to me like you are trying to pass an array in a scalar context so it is possible that you are setting follow to 1, the number of elements in the array (the number of lines in the file).
Assuming there is only a single line of IDs in your file, does the following work:
open UID_FILE, "/tmp/uids" or die $!;
# Load the first line of uids
my $uid_line = <UID_FILE>;
# Remove apostrophes from input.
# This may or may not be necessary
$uid_line =~ s/'//g;
# Don't forget to close the file
close(UID_FILE);
my $done = AnyEvent->condvar;
my $nt_filter = AnyEvent::Twitter::Stream->new(
username => $cf{account},
password => $cf{password},
method => 'filter',
follow => $uid_line,
on_tweet => sub {
#some code....
},
on_error => sub {
my $error = shift;
debug "ERROR: $error";
},
timeout => 45,
);
$done->recv;
You will probably need to strip the leading and trailing apostrophes from your input line. For example:
$uid_line =~ s/^'//;
$uid_line =~ s/'$//;
You could probably get away with just removing all apostrophes, e.g.:
$uid_line =~ s/'//g;