Hi,

I would like to ask for an explanation or hint to my error for my
attempt to use regexec(3) to match null-characters ('\0').

To illustrate it, I wrote the attached test-program and what I do not
understand is why I get false match-positions when testing with a string
that contains '\0' (I am not absolutely sure if '.' is supposed to match '\0').

Here is some "normal" output:

$ printf ".\nab\n" | ./test_regex
Compiling regex "."
Testing string "ab"...
regexec match: pos 0 length 1
        "ab"
Testing string "b"...
regexec match: pos 1 length 1
        "b"
Testing string ""...

But when I insert a '\0' into that string, the result is confusing to
me:

$ printf ".\na\0b\n" | ./test_regex
Compiling regex "."
Testing string "a"...
regexec match: pos 0 length 1
        "a"
Testing string ""...
regexec match: pos 2 length 1
        "b"
Testing string "b"...
regexec match: pos 2 length 1
        "b"
Testing string ""...

My appologies in advance should this question be easy to answer myself
if I had googled it correctly.

Regards,

Dirk