Re: How is perl able to handle the null byte?

[Joost]

Yup, C treats a 0 byte as the end of a string. And yes perl is written in C. However, perl strings are not C strings.

In C a string is nothing more than a pointer to the first character of the string. C can't know how long a string is except by counting all the characters from the start until the first 0 byte. You need to know the length of a string in order to do things like copy or compare them.

Perl's strings are C structs that include (amongst other things) a pointer to the first character, AND the length of the string. Since perl doesn't need a special terminating character you can use 0 characters in the middle of a string too.

Note that internally perl strings are still 0-terminated in order to facilitate interoperation with functions that expect C style strings. Also note that sending strings with embedded 0 characters to system calls or XS libraries does not always work as you'd expect, though all the buildin string and IO operations (regexes, print etc) should work correctly.

[muba]

A struct is basically like creating your own data type, right?

However, I understand now. That was fairly simple, actually...
Thank you!

[Joost]

A struct is a "complex" type. That means a struct contains a fixed number of fields that can be of different types themselves. A bit like a perl hash but with a fixed number of key-value pairs.

PerlGuts Illustrated has some nice diagrams.