[SOLVED] Why does PHP have a Uniqid Function if Microtime is truly unique?

[limitphp]

Why would PHP have a uniquid function that creates a uniqueID if they already have a microtime function that truly creates a unqiueID, regardless of time, day, month, or year?

 

This isn't a pressing question, I'm just curious.

[discomatt]

Can be useful, for instance, if you generate identifiers simultaneously on several hosts that might happen to generate the identifier at the same microsecond.

 

Microtime doesn't make any attempts to be unique, it simply returns the current time at a microsecond level.

[rhodesa]

that is why i concatenate getmypid() onto microtime for my unique identifiers

[DarkWater]

that is why i concatenate getmypid() onto microtime for my unique identifiers

 

Clever.

[limitphp]

Can be useful, for instance, if you generate identifiers simultaneously on several hosts that might happen to generate the identifier at the same microsecond.

 

Microtime doesn't make any attempts to be unique, it simply returns the current time at a microsecond level.

 

Yeah, I has posted this before you had replied to the other post pretty much answering the question in this post.

 

Of course, I was thinking, I could just have the ID be auto_increment (1,2,3,4,5,etc)....

that insures that every entry is unique.

Then just attach some word to the value.

 

So then every value will be example:

1keyword, 2keyword, 3keyword, 4keyword, 5keyword

 

That will insure that people can't guess it....

 

Then md5 that value and store that in the cookie.

 

It would be unique and it would be very difficult for people to guess it, unless they found out my keyword.

 

 

[discomatt]

that is why i concatenate getmypid() onto microtime for my unique identifiers

 

And if both servers have the same PID for php?

[DarkWater]

Every request starts a new child, so the PID would be different for any given microtime().

[discomatt]

Upon closer inspection of getmypid(), I feel stupid

[DarkWater]

Upon closer inspection of getmypid(), I feel stupid

 

 

Btw, Rhodesa, that's really ingenious.  I'm certainly going to use that next time I need a random ID.