[PATCH] substr() returns false View as Markdown

Not sure if/how this should be changed.
Isn't it a mistake to give a start position at the end or beyond the
string? In this case, doesn't it make sense to return false?

Andi

At 02:39 PM 11/19/2003 +0100, Morten Poulsen wrote:

Hi,

Even though this is documented, it is strange behaviour: If the from
parameter to substr() is at, or past, the end of the input string, the
function returns false.

The function is documented as
string substr ( string string, int start [, int length])

IMHO substr() should either

1. be changed to do like Perl, which returns an error only if start is
   beyond the end (not at):
   (from http://www.perldoc.com/perl5.6/pod/func/substr.html)
   my $null = substr $name, 6, 2; # returns '' (no warning)
   my $oops = substr $name, 7; # returns undef, with warning

2. be changed to return an empty string, if start is either at or beyond
   the end of the input string.

I have attached patches for both solutions.

If you don't change it to be like Perl, I think it should be noted in
the documentation (as with chop()).
If, on the other hand, it is changed to behave like Perl, I think it
should be emphasized that you are not guaranteed that the result is a
string, because this will cause (eg. has caused us) problems when using
the result as part of the $data array to PEAR DB::execute().

Happy hacking,
Morten

--
Morten Poulsen morten-Qg2caEh8@afdelingp.dk
http://www.afdelingp.dk/