php regular expression replacement and regular replacement function

php regular expression replacement and regular replacement function
/ *
Here we are to specify the regular out of the inner space replaced by something else, so we will use the regular replacement function preg_replace, the following example is

The text has the following label

<img style src = "<? = $ url?> / images / styleno.jpg" width = "30" height = "30" />
<img style src = "<? = $ url?> / images / styleno.jpg" width = "30" height = "30" />
<img src = "images / styleno.jpg" width = "30" height = "30" />
<img src = "images / styleno.jpg" width = "30" height = "30" />
Would like to replace them with a style with a regular one like <img src = "<? = $ Url?> / Images / styleno.jpg" width = "30" height = "30" />
No style is replaced by <img src = "<? = $ Path?> / Images / styleno.jpg" width = "30" height = "30" />

* /

$ content1 = '<img style src = "<? = $ url?> / images / styleno.jpg" width = "30" height = "30" />';
$ content = '<img style src = "/ images / styleno.jpg" width = "30" height = "30" />';
$ a = '<img src = "<? = $ url?> / images / styleno.jpg" width = "30" height = "30" />';
echo preg_replace ('/ <imgs + styles + src = [' "]? [^ '"] * [' "]? s +. * /> / i ', $ a, $ content);

$ content1 = '<img src = "images / styleno.jpg" width = "30" height = "30" />';
$ b = '<img src = "<? = $ path?> / images / styleno.jpg" width = "30" height = "30" />';
echo preg_replace ('/ <img src = [' "]? [^ '"] * [' "]? s +. * /> / i ', $ b, $ content1);