[pmwiki-devel] Email pattern...

[Guillermo Calderon - INCO]

Patrick R. Michaud wrote:
> On Thu, May 31, 2007 at 07:39:24PM -0400, The Editor wrote:
> 
>>On 5/31/07, Patrick R. Michaud <pmichaud at pobox.com> wrote:
>>
>>>On Thu, May 31, 2007 at 01:53:46PM -0700, Martin Fick wrote:
>>>
>>>>--- "Patrick R. Michaud" <pmichaud at pobox.com> wrote:
>>>>Well, from here:
>>>>
>>>>http://www.regular-expressions.info/email.html
>>
>>The link above was quite interesting reading. No clue my simple
>>question would generate such interesting discussion.
>>
>>For my purposes, however, the double slash solved the basic problem.
>>I'm curious why the single slash did not escape the dot while the
>>double slash did. Can any one explain that?
> 


It depends on using simple or double quotes.
If a string is writen between double quotes, php do some processing 
previous to pass the string to the function; in particular every 
single backslash is removed, since backslash is a special character in 
a double quoted string used for: avoiding variable interpolation, 
inserting double quotes in the string, writing control characters like 
\n, \r, \b, etc.