RegEx返回一个空数组

Question

So, I'm trying to catch 3 letter word from a text file. I've created a RegEx, but it return an EMPTY array. And I'm not able to figure out why! Here's a part of the text file.

================================================
Header of File with time and date
================================================
Loaded options from XML file: '/Thisis/some/Users/sumuser/Desktop/SM_Folder/ESQ/Virtual_Proof_ESQ/processing/ID2PDF_options.xml
extendedPrintPDF started
Postfix '3.0' was append from file 'ESQ030112ELAM_lo-metadata.xml' for file: '/Thisis/some/Users/sumuser/Desktop/SM_Folder/ESQ/Virtual_Proof_ESQ/processing/someFile.indd
printPDF started
PDF Export Preset: Some preset
PDF file created: ''/Thisis/some/Users/sumuser/Desktop/SM_Folder/ESQ/Virtual_Proof_ESQ/processing/someFile.pdf'.
File someFileName.xml removed
postprocessingDocument started
INDD file removed: '/Thisis/some/Users/sumuser/Desktop/SM_Folder/ESQ/Virtual_Proof_ESQ/processing/someFile.indd

Here's the RegEx I have:

/^Loaded options from XML file: '\/.*\/SM_Folder\/([a-zA-Z]{3})\/[a-zA-Z]+_Proof_\1\/processing\/ID2PDF_options.xml$/im

If I remove \ in front of \/([a-zA-Z]{3}), I get an Unknown modifier:( error.

Can someone please tell me what I need to do to grab the "ESQ" from the first line of the record? The 3 letter word would be different in other records and so, I can't really design my RegEx to catch only ESQ. It might be ABC or XYZ for example. But, it would remain as a 3 letter word. Any useful inputs would be appreciated.

Also, this post didnt help much either: PHP Regex returning array with values empty

Note:

options.xml 

doesn't end with ' because it is not supposed to!

Answer 1

The regular expression pattern and the file-data you have provided in your question are not resulting in an empty array. At least not for me (read on later). With preg_match_all I'll get one match properly. I've using this code:

$file = <<<FILE
================================================
Header of File with time and date
================================================
Loaded options from XML file: '/Thisis/some/Users/sumuser/Desktop/SM_Folder/ESQ/Virtual_Proof_ESQ/processing/ID2PDF_options.xml
extendedPrintPDF started
Postfix '3.0' was append from file 'ESQ030112ELAM_lo-metadata.xml' for file: '/Thisis/some/Users/sumuser/Desktop/SM_Folder/ESQ/Virtual_Proof_ESQ/processing/someFile.indd
printPDF started
PDF Export Preset: Some preset
PDF file created: ''/Thisis/some/Users/sumuser/Desktop/SM_Folder/ESQ/Virtual_Proof_ESQ/processing/someFile.pdf'.
File someFileName.xml removed
postprocessingDocument started
INDD file removed: '/Thisis/some/Users/sumuser/Desktop/SM_Folder/ESQ/Virtual_Proof_ESQ/processing/someFile.indd
FILE;

$pattern = '/^Loaded options from XML file: \'\/.*\/SM_Folder\/([a-zA-Z]{3})\/[a-zA-Z]+_Proof_\1\/processing\/ID2PDF_options.xml$/im';

$result = preg_match_all($pattern, $file, $matches);

var_dump($result, $matches);

Result:

int(1)
array(2) {
  [0] =>
  array(1) {
    [0] =>
    string(127) "Loaded options from XML file: '/Thisis/some/Users/sumuser/Desktop/SM_Folder/ESQ/Virtual_Proof_ESQ/processing/ID2PDF_options.xml"
  }
  [1] =>
  array(1) {
    [0] =>
    string(3) "ESQ"
  }
}

You probably get a result similar as the following (which is also by the exact same code as above but on a different computer as demo here):

int(0)
array(2) {
  [0]=>
  array(0) {
  }
  [1]=>
  array(0) {
  }
}

If you get this result, than this is a sign that the ^ and $ in multiline mode do not match the end of lines because you don't have there but most likely the CRLF sequence (DOS/Windows line-ending). You can take all these sequences by using the ANYCRLF option:

$pattern = '/(*ANYCRLF)^Loaded options from XML file: \'\/.*\/SM_Folder\/([a-zA-Z]{3})\/[a-zA-Z]+_Proof_\1\/processing\/ID2PDF_options.xml$/im';
             ^^^^^^^^^^

This then should give you the results. See the working demo.