preg_match 一行中的所有出现

Question

示例（文件=xref.tex）：

This is a example string and first line with <xref>id1</xref>then,<xref>id2</xref>and with no line breaks<xref>id3</xref>.
This is a second line which has <xref>id4</xref>

示例（文件=id）：

id1 eqvalue1
id2 eqvalue2
id3 eqvalue3
id4 eqvalue4

要求：每个唯一的id都有一个等价的值。我需要在 "xref.tex" 文件中每次出现时替换 id 的等效值。

目前已尝试：

    $xref=file("xref.tex");
    $idfile=file("id");
    for($y=0;$y<count($xref);$y++){
      for($z=0;$z<count($idfile);$z++){
        $idvalue=explode(" ",$idfile[$z])//exploding based on space charac
        $id1=$idvalue[0]; //this is equivalent value of unique id
        $id2=$idvalue[1];  // this is unique id
        preg_match( '/<xref>(.*?)<\/xref/', $xref[$y], $match );
        //getting the content between "<xref>"and "</xref>"
        if($match[1]===$id2{
          $xref[$y]=str_replace($match[1],$id1,$xref[$y]);}
          //here first occurrence of id is replaced. how to replace  
          //second occurrence of id in a line as  
          //preg_match( '/<xref>(.*?)<\/xref/', $xref[$y], $match )
          //this regex focusing on first occurrence only every time.
          //???? prob here is how can i do this logic in all the occurrences 
          //in each line 
        }
     }
   }

预期输出：

This is a example string and first line with <xref>eqvalue1</xref>then,<xref>eqvalue2</xref>and with no line breaks<xref>eqvalue3</xref>.
This is a second line which has <xref>eqvalue4</xref>

Answer 1

将文件 "id" 读取为 space 分隔的 csv 到一个数组，然后使用该数组和 preg_replace 在另一个文件上作为字符串使用 file_get_contents.

Answer 2

试试这个：

$re = "/(<xref>[^\d]+)(\d)(<\/xref)/m";
$str = "This is a example string and first line with <xref>id1</xref>then,<xref>id2</xref>and with no line breaks<xref>id3</xref>. This is a second line which has <xref>id4</xref>";
$subst = "eqvalue";

$result = preg_replace($re, $subst, $str);

Live demo

Answer 3

这是我的理解。文件内容xref.tex如下

<xref>id1</xref><xref>id2</xref><xref>id3</xref><xref>id4</xref> //line 1
<xref>id2</xref><xref>id3</xref> //line 2
<xref>id4</xref> //line 3
... and so on

首先，您必须修复正则表达式。您在结尾处缺少 >。应该是

/<xref>(.*?)<\/xref>/

然后你需要使用 preg_match_all 而不是建议的 preg_match。

我稍微修改了代码。如果您在一行中重复相同的 ID，这也应该有效。

$xref=file("xref.tex");
$idfile=file("id");
for($y=0;$y<count($xref);$y++)
{
    preg_match_all( '/<xref>(.*?)<\/xref/', $xref[$y], $match ); //get all matches and store them in *match*
    for($z=0;$z<count($idfile);$z++)
    {
        $idvalue=explode(" ",$idfile[$z]);
        $id1=$idvalue[0]; 
        $id2=$idvalue[1];  
        //Below, we're replacing all the matches in line with corresponding value. Edit: Maybe not the best way, but it will give you an idea.
        foreach($match[0] as $matchItem)
            $xref[$y]=str_replace($matchItem,$id1,$xref[$y]);
    }    
}

编辑

您可能需要查看 preg_replace。我认为这将是一个更好的解决方案。

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