PHP regular expression replace beginning and end of string if match exists

Question

could you please help me on this problem I want in PHP to replace the begining and the end of a string if match exists, as example:

source strings :
tr_abcdef_lang or tr_abcdef or tr_abcdef_cba
I want to replace the string to have it like this:
fk_abcdef or fk_abcdef_cba

I mean if strings ends with _lang or _language to remove it, and at the begining replace everything before the first _ with fk .

So more examples :

tr_abcdef => fk_abcdef
tr_abcdef_language  => fk_abcdef
x_abc_cba => fk_abc_cba
x_abc_cba_lang => fk_abc_cba
t_tablename_languages => fk_tablename

Answer 1

i solve your regex problem

$pattern = "/^([a-zA-Z]+?)_(\w+?)([_trans|_translation|_languages]*?)$/i"; 
$replacement = 'fk_$2'; 
$fk_field_name = preg_replace($pattern,$replacement, "x_abc_cba_gsd_lang");
echo $fk_field_name;

my code

Try this ~(.*?)_(.*)_(.*)~si

preg_match_all( '~(.*?)_(.*)_(.*)~si', "x_abc_cba",$M);
$E='';
if($M[3][0]!="lang" and $M[3][0]!="language" and $M[3][0]!="languages"){
$E="_".$M[3][0];
}
echo ("fk_".$M[2][0].$E);

or try it without php regular expression

$String="x_abc_cba_lang";
$xp=explode("_",$String);
$xp[0]="fk";
end($xp);
$Ek=key($xp);
if($xp[$Ek]=="lang" or $xp[$Ek]=="language" or $xp[$Ek]=="languages"){
   unset($xp[$Ek]);
}
echo implode("_",$xp);

Answer 2

Thanks for all who tried to help

i found the solutions and it looks like:

$pattern = "/^([a-zA-Z]+?)_(\w+?)(_trans|_translation|_languages)?$/i";             
$replacement    = 'fk_$2';
$fk_field_name = preg_replace($pattern, $replacement, $tbl_name); 

Thanks again and best regards

Wael