I’ve recently been investigating the use of Universally Unique Identifiers with PHP. A suprising google search for php uuid yields the php function uniqid() which does not produce a uuid at all. I searched further and found no shortage of PHP classes and functions which will generate uuid’s. This is likely due to the fact that there are no core functions built into PHP to handle uuid generation.

I did manage to find a uuid pecl extension that seems to work well.

Ubuntu Install

Basic Usage

I could not find any documentation which lists or describes the functions provided by the extension. Digging through the source code yielded this list of functions:

Generate a new uuid
string uuid_create ( [ int $uuid_type ] )
valid parameters: UUID_TYPE_DEFAULT, UUID_TYPE_TIME, UUID_TYPE_RANDOM

Check if a given uuid string is valid
bool uuid_is_valid ( string $uuid )

Compare two uuid strings
int uuid_compare ( string $uuid1, string $uuid2 )

Check if a uuid string is the null 00000000-0000-0000-0000-000000000000
bool uuid_is_null ( string $uuid )

Get the uuid’s type
int uuid_type ( string $uuid )

Get the uuid’s variant
int uuid_variant ( string $uuid )

Extract the creation time from a time based uuid as unix timestamp
int uuid_time ( string $uuid )

Get the uuid creator mac address
string uuid_mac ( string $uuid )

Convert uuid string to binary
string uuid_parse ( string $uuid )

Convert uuid binary to string
string uuid_unparse ( string $uuid )

php5-uuid?

Through apt-get, there is a package named php5-uuid. Prior to installing the pecl package, I did try php5-uuid but was met with “Warning: uuid_create() expects exactly 1 parameter” when trying to use it. There is a description of this problem and the two packages here. I decided to avoid the fuss and use the pecl package.