CSS选择器的正则表达式 - PHP

Question

Does anyone know what the most robust regex would be to select all selectors from a css declaration? Below is CSS code for non-standard CSS that would be a good test case.

.somenormalstyledeclaration 
{
    width:100%;
    height:100%;
    background-image: url(images/fallback-gradient.png);
}
.somenormalstyle1, .somenormalstyle2 
{
    width:100%;
    height:100%;
    background-image: url(images/fallback-gradient.png);
}
.gradient-bg 
{
   background-color: #1a82f7;
   background-image: url(images/fallback-gradient.png);
   background-image: -webkit-gradient(linear, 0% 0%, 0% 100%, from(#2F2727), to(#1a82f7));
   background-image: -webkit-linear-gradient(top, #2F2727, #1a82f7);
   background-image:    -moz-linear-gradient(top, #2F2727, #1a82f7);
   background-image:     -ms-linear-gradient(top, #2F2727, #1a82f7);
   background-image:      -o-linear-gradient(top, #2F2727, #1a82f7);
}

@-webkit-keyframes bounce_circle 
{
    0% 
    {
        opacity:0.3;
    }
    50% 
    {
        opacity:1;
        background-color:#111
    }
    100% 
    {
        opacity:0.3;
    }
}

Answer 1

This should work mostly. It's a few steps, but not as good as a full parser.

1. Replace all newlines with a space character
2. Assuming you never use strings including { or }, you can replace /\{[^\}]\}/ with a ,
3. Split all the text into an array on each , and ; character
4. Trim all whitespace from the beginning and end of each selector

Every element of the array should be a selector or an "at-rule" (i.e. @charset utf-8;).

I have probably missed some other edge cases, but this should work as a quick-and-dirty solution for most cases.