Provided by: libredis-perl_1.9670-1_all 
NAME
Redis - Perl binding for Redis database
VERSION
version 1.967
SYNOPSIS
## Defaults to $ENV{REDIS_SERVER} or 127.0.0.1:6379
my $redis = Redis->new;
my $redis = Redis->new(server => 'redis.example.com:8080');
## Set the connection name (requires Redis 2.6.9)
my $redis = Redis->new(
server => 'redis.example.com:8080',
name => 'my_connection_name',
);
my $generation = 0;
my $redis = Redis->new(
server => 'redis.example.com:8080',
name => sub { "cache-$$-".++$generation },
);
## Use UNIX domain socket
my $redis = Redis->new(sock => '/path/to/socket');
## Enable auto-reconnect
## Try to reconnect every 1s up to 60 seconds until success
## Die if you can't after that
my $redis = Redis->new(reconnect => 60);
## Try each 100ms upto 2 seconds (every is in milisecs)
my $redis = Redis->new(reconnect => 2, every => 100);
## Enable connection timeout (in seconds)
my $redis = Redis->new(cnx_timeout => 60);
## Enable read timeout (in seconds)
my $redis = Redis->new(read_timeout => 0.5);
## Enable write timeout (in seconds)
my $redis = Redis->new(write_timeout => 1.2);
## Use all the regular Redis commands, they all accept a list of
## arguments
## See http://redis.io/commands for full list
$redis->get('key');
$redis->set('key' => 'value');
$redis->sort('list', 'DESC');
$redis->sort(qw{list LIMIT 0 5 ALPHA DESC});
## Add a coderef argument to run a command in the background
$redis->sort(qw{list LIMIT 0 5 ALPHA DESC}, sub {
my ($reply, $error) = @_;
die "Oops, got an error: $error\n" if defined $error;
print "$_\n" for @$reply;
});
long_computation();
$redis->wait_all_responses;
## or
$redis->wait_one_response();
## Or run a large batch of commands in a pipeline
my %hash = _get_large_batch_of_commands();
$redis->hset('h', $_, $hash{$_}, sub {}) for keys %hash;
$redis->wait_all_responses;
## Publish/Subscribe
$redis->subscribe(
'topic_1',
'topic_2',
sub {
my ($message, $topic, $subscribed_topic) = @_
## $subscribed_topic can be different from topic if
## you use psubscribe() with wildcards
}
);
$redis->psubscribe('nasdaq.*', sub {...});
## Blocks and waits for messages, calls subscribe() callbacks
## ... forever
my $timeout = 10;
$redis->wait_for_messages($timeout) while 1;
## ... until some condition
my $keep_going = 1; ## other code will set to false to quit
$redis->wait_for_messages($timeout) while $keep_going;
$redis->publish('topic_1', 'message');
DESCRIPTION
Pure perl bindings for <http://redis.io/>
This version supports protocol 2.x (multi-bulk) or later of Redis available at
<https://github.com/antirez/redis/>.
This documentation lists commands which are exercised in test suite, but additional
commands will work correctly since protocol specifies enough information to support almost
all commands with same piece of code with a little help of "AUTOLOAD".
PIPELINING
Usually, running a command will wait for a response. However, if you're doing large
numbers of requests, it can be more efficient to use what Redis calls pipelining: send
multiple commands to Redis without waiting for a response, then wait for the responses
that come in.
To use pipelining, add a coderef argument as the last argument to a command method call:
$r->set('foo', 'bar', sub {});
Pending responses to pipelined commands are processed in a single batch, as soon as at
least one of the following conditions holds:
• A non-pipelined (synchronous) command is called on the same connection
• A pub/sub subscription command (one of "subscribe", "unsubscribe", "psubscribe", or
"punsubscribe") is about to be called on the same connection.
• One of "wait_all_responses" or "wait_one_response" methods is called explicitly.
The coderef you supply to a pipelined command method is invoked once the response is
available. It takes two arguments, $reply and $error. If $error is defined, it contains
the text of an error reply sent by the Redis server. Otherwise, $reply is the non-error
reply. For almost all commands, that means it's "undef", or a defined but non-reference
scalar, or an array ref of any of those; but see "keys", "info", and "exec".
Note the contrast with synchronous commands, which throw an exception on receipt of an
error reply, or return a non-error reply directly.
The fact that pipelined commands never throw an exception can be particularly useful for
Redis transactions; see "exec".
ENCODING
There is no encoding feature anymore, it has been deprecated and finally removed. This
module consider that any data sent to the Redis server is a raw octets string, even if it
has utf8 flag set. And it doesn't do anything when getting data from the Redis server.
So, do you pre-encoding or post-decoding operation yourself if needed !
METHODS
Constructors
new
my $r = Redis->new; # $ENV{REDIS_SERVER} or 127.0.0.1:6379
my $r = Redis->new( server => '192.168.0.1:6379', debug => 0 );
my $r = Redis->new( server => '192.168.0.1:6379', encoding => undef );
my $r = Redis->new( sock => '/path/to/sock' );
my $r = Redis->new( reconnect => 60, every => 5000 );
my $r = Redis->new( password => 'boo' );
my $r = Redis->new( on_connect => sub { my ($redis) = @_; ... } );
my $r = Redis->new( name => 'my_connection_name' );
my $r = Redis->new( name => sub { "cache-for-$$" });
The "server" parameter specifies the Redis server we should connect to, via TCP. Use the
'IP:PORT' format. If no "server" option is present, we will attempt to use the
"REDIS_SERVER" environment variable. If neither of those options are present, it defaults
to '127.0.0.1:6379'.
Alternatively you can use the "sock" parameter to specify the path of the UNIX domain
socket where the Redis server is listening.
The "REDIS_SERVER" can be used for UNIX domain sockets too. The following formats are
supported:
• /path/to/sock
• unix:/path/to/sock
• 127.0.0.1:11011
• tcp:127.0.0.1:11011
The "reconnect" option enables auto-reconnection mode. If we cannot connect to the Redis
server, or if a network write fails, we enter retry mode. We will try a new connection
every "every" milliseconds (1000ms by default), up-to "reconnect" seconds.
Be aware that read errors will always thrown an exception, and will not trigger a retry
until the new command is sent.
If we cannot re-establish a connection after "reconnect" seconds, an exception will be
thrown.
The "cnx_timeout" option enables connection timeout. The Redis client will wait at most
that number of seconds (can be fractional) before giving up connecting to a server.
The "read_timeout" option enables read timeout. The Redis client will wait at most that
number of seconds (can be fractional) before giving up when reading from the server.
The "write_timeout" option enables write timeout. The Redis client will wait at most that
number of seconds (can be fractional) before giving up when reading from the server.
If your Redis server requires authentication, you can use the "password" attribute. After
each established connection (at the start or when reconnecting), the Redis "AUTH" command
will be send to the server. If the password is wrong, an exception will be thrown and
reconnect will be disabled.
You can also provide a code reference that will be immediately after each successful
connection. The "on_connect" attribute is used to provide the code reference, and it will
be called with the first parameter being the Redis object.
You can also set a name for each connection. This can be very useful for debugging
purposes, using the "CLIENT LIST" command. To set a connection name, use the "name"
parameter. You can use both a scalar value or a CodeRef. If the latter, it will be called
after each connection, with the Redis object, and it should return the connection name to
use. If it returns a undefined value, Redis will not set the connection name.
Please note that there are restrictions on the name you can set, the most important of
which is, no spaces. See the CLIENT SETNAME documentation
<http://redis.io/commands/client-setname> for all the juicy details. This feature is safe
to use with all versions of Redis servers. If "CLIENT SETNAME" support is not available
(Redis servers 2.6.9 and above only), the name parameter is ignored.
The "debug" parameter enables debug information to STDERR, including all interactions with
the server. You can also enable debug with the "REDIS_DEBUG" environment variable.
Connection Handling
quit
$r->quit;
Closes the connection to the server. The "quit" method does not support pipelined
operation.
ping
$r->ping || die "no server?";
The "ping" method does not support pipelined operation.
client_list
@clients = $r->client_list;
Returns list of clients connected to the server. See CLIENT LIST documentation
<http://redis.io/commands/client-list> for a description of the fields and their meaning.
client_getname
my $connection_name = $r->client_getname;
Returns the name associated with this connection. See "client_setname" or the "name"
parameter to "new" for ways to set this name.
client_setname
$r->client_setname('my_connection_name');
Sets this connection name. See the CLIENT SETNAME documentation
<http://redis.io/commands/client-setname> for restrictions on the connection name string.
The most important one: no spaces.
Pipeline management
wait_all_responses
Waits until all pending pipelined responses have been received, and invokes the pipeline
callback for each one. See "PIPELINING".
wait_one_response
Waits until the first pending pipelined response has been received, and invokes its
callback. See "PIPELINING".
Transaction-handling commands
Warning: the behaviour of these commands when combined with pipelining is still under
discussion, and you should NOT use them at the same time just now.
You can follow the discussion to see the open issues with this
<https://github.com/melo/perl-redis/issues/17>.
multi
$r->multi;
discard
$r->discard;
exec
my @individual_replies = $r->exec;
"exec" has special behaviour when run in a pipeline: the $reply argument to the pipeline
callback is an array ref whose elements are themselves "[$reply, $error]" pairs. This
means that you can accurately detect errors yielded by any command in the transaction, and
without any exceptions being thrown.
Commands operating on string values
set
$r->set( foo => 'bar' );
$r->setnx( foo => 42 );
get
my $value = $r->get( 'foo' );
mget
my @values = $r->mget( 'foo', 'bar', 'baz' );
incr
$r->incr('counter');
$r->incrby('tripplets', 3);
decr
$r->decr('counter');
$r->decrby('tripplets', 3);
exists
$r->exists( 'key' ) && print "got key!";
del
$r->del( 'key' ) || warn "key doesn't exist";
type
$r->type( 'key' ); # = string
Commands operating on the key space
keys
my @keys = $r->keys( '*glob_pattern*' );
my $keys = $r->keys( '*glob_pattern*' ); # count of matching keys
Note that synchronous "keys" calls in a scalar context return the number of matching keys
(not an array ref of matching keys as you might expect). This does not apply in pipelined
mode: assuming the server returns a list of keys, as expected, it is always passed to the
pipeline callback as an array ref.
randomkey
my $key = $r->randomkey;
rename
my $ok = $r->rename( 'old-key', 'new-key', $new );
dbsize
my $nr_keys = $r->dbsize;
Commands operating on lists
See also Redis::List for tie interface.
rpush
$r->rpush( $key, $value );
lpush
$r->lpush( $key, $value );
llen
$r->llen( $key );
lrange
my @list = $r->lrange( $key, $start, $end );
ltrim
my $ok = $r->ltrim( $key, $start, $end );
lindex
$r->lindex( $key, $index );
lset
$r->lset( $key, $index, $value );
lrem
my $modified_count = $r->lrem( $key, $count, $value );
lpop
my $value = $r->lpop( $key );
rpop
my $value = $r->rpop( $key );
Commands operating on sets
sadd
my $ok = $r->sadd( $key, $member );
scard
my $n_elements = $r->scard( $key );
sdiff
my @elements = $r->sdiff( $key1, $key2, ... );
my $elements = $r->sdiff( $key1, $key2, ... ); # ARRAY ref
sdiffstore
my $ok = $r->sdiffstore( $dstkey, $key1, $key2, ... );
sinter
my @elements = $r->sinter( $key1, $key2, ... );
my $elements = $r->sinter( $key1, $key2, ... ); # ARRAY ref
sinterstore
my $ok = $r->sinterstore( $dstkey, $key1, $key2, ... );
sismember
my $bool = $r->sismember( $key, $member );
smembers
my @elements = $r->smembers( $key );
my $elements = $r->smembers( $key ); # ARRAY ref
smove
my $ok = $r->smove( $srckey, $dstkey, $element );
spop
my $element = $r->spop( $key );
srandmemeber
my $element = $r->srandmember( $key );
srem
$r->srem( $key, $member );
sunion
my @elements = $r->sunion( $key1, $key2, ... );
my $elements = $r->sunion( $key1, $key2, ... ); # ARRAY ref
sunionstore
my $ok = $r->sunionstore( $dstkey, $key1, $key2, ... );
Commands operating on hashes
Hashes in Redis cannot be nested as in perl, if you want to store a nested hash, you need
to serialize the hash first. If you want to have a named hash, you can use Redis-hashes.
You will find an example in the tests of this module t/01-basic.t
hset
Sets the value to a key in a hash.
$r->hset('hashname', $key => $value); ## returns true on success
hget
Gets the value to a key in a hash.
my $value = $r->hget('hashname', $key);
hexists
if($r->hexists('hashname', $key) {
## do something, the key exists
}
else {
## the key does not exist
}
hdel
Deletes a key from a hash
if($r->hdel('hashname', $key)) {
## key is deleted
}
else {
## oops
}
hincrby
Adds an integer to a value. The integer is signed, so a negative integer decrements.
my $key = 'testkey';
$r->hset('hashname', $key => 1); ## value -> 1
my $increment = 1; ## has to be an integer
$r->hincrby('hashname', $key => $increment); ## value -> 2
$increment = 5;
$r->hincrby('hashname', $key => $increment); ## value -> 7
$increment = -1;
$r->hincrby('hashname', $key => $increment); ## value -> 6
hsetnx
Adds a key to a hash unless it is not already set.
my $key = 'testnx';
$r->hsetnx('hashname', $key => 1); ## returns true
$r->hsetnx('hashname', $key => 2); ## returns false because key already exists
hmset
Adds multiple keys to a hash.
$r->hmset('hashname', 'key1' => 'value1', 'key2' => 'value2'); ## returns true on success
hmget
Returns multiple keys of a hash.
my @values = $r->hmget('hashname', 'key1', 'key2');
hgetall
Returns the whole hash.
my %hash = $r->hgetall('hashname');
hkeys
Returns the keys of a hash.
my @keys = $r->hkeys('hashname');
hvals
Returns the values of a hash.
my @values = $r->hvals('hashname');
hlen
Returns the count of keys in a hash.
my $keycount = $r->hlen('hashname');
Sorting
sort
$r->sort("key BY pattern LIMIT start end GET pattern ASC|DESC ALPHA');
Publish/Subscribe commands
When one of "subscribe" or "psubscribe" is used, the Redis object will enter PubSub mode.
When in PubSub mode only commands in this section, plus "quit", will be accepted.
If you plan on using PubSub and other Redis functions, you should use two Redis objects,
one dedicated to PubSub and the other for regular commands.
All Pub/Sub commands receive a callback as the last parameter. This callback receives
three arguments:
• The published message.
• The topic over which the message was sent.
• The subscribed topic that matched the topic for the message. With "subscribe" these
last two are the same, always. But with "psubscribe", this parameter tells you the
pattern that matched.
See the Pub/Sub notes <http://redis.io/topics/pubsub> for more information about the
messages you will receive on your callbacks after each "subscribe", "unsubscribe",
"psubscribe" and "punsubscribe".
publish
$r->publish($topic, $message);
Publishes the $message to the $topic.
subscribe
$r->subscribe(
@topics_to_subscribe_to,
sub {
my ($message, $topic, $subscribed_topic) = @_;
...
},
);
Subscribe one or more topics. Messages published into one of them will be received by
Redis, and the specified callback will be executed.
unsubscribe
$r->unsubscribe(@topic_list, sub { my ($m, $t, $s) = @_; ... });
Stops receiving messages for all the topics in @topic_list.
psubscribe
my @topic_matches = ('prefix1.*', 'prefix2.*');
$r->psubscribe(@topic_matches, sub { my ($m, $t, $s) = @_; ... });
Subscribes a pattern of topics. All messages to topics that match the pattern will be
delivered to the callback.
punsubscribe
my @topic_matches = ('prefix1.*', 'prefix2.*');
$r->punsubscribe(@topic_matches, sub { my ($m, $t, $s) = @_; ... });
Stops receiving messages for all the topics pattern matches in @topic_list.
is_subscriber
if ($r->is_subscriber) { say "We are in Pub/Sub mode!" }
Returns true if we are in Pub/Sub mode.
wait_for_messages
my $keep_going = 1; ## Set to false somewhere to leave the loop
my $timeout = 5;
$r->wait_for_messages($timeout) while $keep_going;
Blocks, waits for incoming messages and delivers them to the appropriate callbacks.
Requires a single parameter, the number of seconds to wait for messages. Use 0 to wait for
ever. If a positive non-zero value is used, it will return after that amount of seconds
without a single notification.
Please note that the timeout is not a commitment to return control to the caller at most
each "timeout" seconds, but more a idle timeout, were control will return to the caller if
Redis is idle (as in no messages were received during the timeout period) for more than
"timeout" seconds.
The "wait_for_messages" call returns the number of messages processed during the run.
Persistence control commands
save
$r->save;
bgsave
$r->bgsave;
lastsave
$r->lastsave;
Scripting commands
eval
$r->eval($lua_script, $num_keys, $key1, ..., $arg1, $arg2);
Executes a Lua script server side.
Note that this commands sends the Lua script every time you call it. See "evalsha" and
"script_load" for an alternative.
evalsha
$r->eval($lua_script_sha1, $num_keys, $key1, ..., $arg1, $arg2);
Executes a Lua script cached on the server side by its SHA1 digest.
See "script_load".
script_load
my ($sha1) = $r->script_load($lua_script);
Cache Lua script, returns SHA1 digest that can be used with "evalsha".
script_exists
my ($exists1, $exists2, ...) = $r->script_exists($scrip1_sha, $script2_sha, ...);
Given a list of SHA1 digests, returns a list of booleans, one for each SHA1, that report
the existence of each script in the server cache.
script_kill
$r->script_kill;
Kills the currently running script.
script_flush
$r->script_flush;
Flush the Lua scripts cache.
Remote server control commands
info
my $info_hash = $r->info;
The "info" method is unique in that it decodes the server's response into a hashref, if
possible. This decoding happens in both synchronous and pipelined modes.
shutdown
$r->shutdown;
The "shutdown" method does not support pipelined operation.
slowlog
my $nr_items = $r->slowlog("len");
my @last_ten_items = $r->slowlog("get", 10);
The "slowlog" command gives access to the server's slow log.
Multiple databases handling commands
select
$r->select( $dbindex ); # 0 for new clients
move
$r->move( $key, $dbindex );
flushdb
$r->flushdb;
flushall
$r->flushall;
ACKNOWLEDGEMENTS
The following persons contributed to this project (alphabetical order):
• Aaron Crane (pipelining and AUTOLOAD caching support)
• Dirk Vleugels
• Flavio Poletti
• Jeremy Zawodny
• sunnavy at bestpractical.com
• Thiago Berlitz Rondon
• Ulrich Habel
• Ivan Kruglov
AUTHORS
• Pedro Melo <melo@cpan.org>
• Damien Krotkine <dams@cpan.org>
COPYRIGHT AND LICENSE
This software is Copyright (c) 2013 by Pedro Melo, Damien Krotkine.
This is free software, licensed under:
The Artistic License 2.0 (GPL Compatible)