PHP特殊字符修剪

Question

I have a set of strings like below :

fw-sophi.watcon.-.120
d-elain.heckop.-.121
sim.boosh.-.134
bh.-.elain.heckop.-.244

How would I trim the following set of strings to return only the middle section? expected return:

sophi.watcon
elain.heckop
sim.boosh
elain.heckop

It isn't practical to trim() the strings manually as there are a lot, how would I do this Programmatically ?

Answer 1

If there are no other patterns, this should be sufficient:

$input = 'fw-sophi.watcon.-.120
d-elain.heckop.-.121
sim.boosh.-.134
bh.-.elain.heckop.-.244';

if (preg_match_all('~(?<key>\w+\.\w+)~', $input, $matches)) {
    print_r($matches['key']);
}

Resulting array:

Array
(
    [0] => sophi.watcon
    [1] => elain.heckop
    [2] => sim.boosh
    [3] => elain.heckop
)

Pattern explanation:

~                 #pattern start 
(                 #start group to capture matched result
    ?<key>        #give a name to group. see $matches['key'].
    \w+           #one or more alphanumeric characters
    \.            #dot character. we need to escape it with \
    \w+           #one or more alphanumeric characters
)                 #end group
~                 #pattern end
x