Programming in Perl

Perl Quick Start

The YottaDB Perl pod (wrapper) was developed by Stefan Traby. YottaDB would like to acknowledge his contribution and thank him for making it available to the YottaDB community.

The YottaDB Perl wrapper requires a minimum YottaDB version of r1.28.

The Perl Quick Start assumes that YottaDB has been already installed as described in the Quick Start section. After installing YottaDB, download the Perl wrapper, install and test it.

$ git clone https://gitlab.com/oesiman/yottadb-perl.git
$ cd yottadb-perl
$ perl Makefile.PL
$ make
$ make test TEST_DB=1 # optional, accesses database
$ sudo make install

Functions

$data = y_data $var [, @subs]

The y_data function returns in $data:

 0  - no value and no subtree
 1  - has a value but no subtree
10  - no value but a subtree
11  - a value and a subtree exists

y_killall ()

The y_killall function kills all local variables.

y_kill_excl [$var0 [,$var1 [,…]]]

The y_kill_excl function deletes all local variables except the specified one(s). y_kill_excl without arguments is the same as y_killall.

y_kill_node $var [, @subs]

Deletes a node but not a subtree.

y_kill_tree $var [, @subs]

Deletes a node and all subtrees.

y_set $var, [@subs,] $value

Sets the variable to $value.

$value = y_get $var [, @subs]

Sets $value to the value of $var [, @subs]. Returns undef if not defined.

$value = y_get_croak $var [, @subs]

Sets $value to the value of $var [, @subs]. Croaks if it is not defined.

$value = y_next $var [, @subs]

Returns the next subscript if it exists or undef if it does not. Here is a sample “order-loop”:

my $x = "";
while (defined ($x = y_next "^global", "subscript", $x)) {
    # ... do something with $x ...
}

$value = y_previous $var [, @subs]

Returns the previous subscript if it exists or undef if it does not.

(@subs) = y_node_next $var [, @subs]

Returns the next node if it exists or an empty list if it does not.

(@subs) = y_node_previous $var [, @subs]

Returns the previous node if it exists or an empty list if it does not.

$incval = y_incr $var [, @subs], $increment

Increments $var [, @subs] by $increment and returns the result in $incval.

$string = y_zwr2str $zwr_encoded_string

Decodes the $zwr_encoded_string to $string.

$zwrstring = y_str2zwr $string

Encodes $string in zwr-format.

$status = y_lock $timeout [, @name1 [, @name2 [,…]]]

Release all lock resources that have been held. If lock resource names are specified then lock all of them, returning 1 upon success or 0 upon failure of locking resources within $timeout limit. For example:

y_lock 0, ["^temp", 1, "two"],
          ["^temp", 3] or die "can't lock";

$status = y_lock_incr $timeout, $var [, @subs]

Try to acquire a lock on $var [, @subs] for $timeout seconds if not currently being held. Increment lock counter if the lock resource is already held. $timeout may be 0.0001 for example. Returns 1 on timeout 0 otherwise.

y_lock_decr $var [, @subs]

Decrement lock counter on $var [, @subs] and release the lock if it reaches 0.