string size in bytes

[gliff]

I seem to be missing part of my brain today. Is there a built-in PHP function or language construct that will tell you the size of a particular variable in bytes? As in, I have a variable named $foo that contains the string “hi there”. I want to know how many bytes “hi there” takes up in memory.

Context

I’m forcing downloads by printing out strings, and would like a proper Content-Length header. If I wanted to get hackish, I know I could output the string to a temporary file and then use filesize() and readfile(), but I’d rather not go that route.

[dcrombie]

Isn't 1 ASCII char === 1 byte?

[gliff]

dcrombie, that all depends on the character encoding. One ASCII character takes one byte to store. However, if you're dealing with multi-byte strings and/or Unicode, one character doesn't necessarily correspond to one byte.

I am/was hoping there's a built-in function I've overlooked that automatically takes all that into account and magically spits out a number.

Thanks for the help though!

[Mr_Fern]

[us3.php.net...]

This function might be helpful. Make sure to read the comment left on that page, it might help also.

[ergophobe]

I guess by forcing mb_strlen() to treat the string as 'latin1' any multi-byte characters get treated as two characters (or more), so your count gets adjusted accordingly.

That's pretty smart.

[gliff]

Tres useful Fern, thanks!