PHP：PHP中的非贪婪匹配

PHP：PHP中的非贪婪匹配

< pre >
<? php
//  替换图片的目录为统一路径
$string   =   " a<img src=\ "a/b / x . png\ " >,Biao,<img src=\ " uploads / y . jpg\ " > " ;

//  /U为非贪婪，这种非贪婪，是从后面向前找，与+?有些区别
$pattern   = " /<img src=\ " ( .* )\ / ( .+ \\ ..+ )\ " >/U " ; 
$replacement   =   " <img src=\ " __IMG_BASE__ / $ 2 \ " > " ; 

$pattern   = " /<img src=\ " ( .* )\ / ( .+ \\ ..+ )\ " >+?/" ;  //  +?结果与上面的不一样

echo   preg_replace ( $pattern ,   $replacement ,   $string );

//  找出所有的图片，图片名
$pattern   = " /<img src=\ " ( .* )\ / ( .+ \\ ..+ )\ " >/U " ;
preg_match_all ( $pattern ,   $string ,   $images );
print_r ( $images );

//  输出图片名
foreach  ( $images [ 2 ]  as   $index   =>   $imageName ) {
     echo   " $imageName<br/> " ;
}
?>