Decoder for backslash-escaped string

Question

What is the correct way in PHP to deal with decoding strings, such as these:

Test1 \\ Test2 \n Test3 \\n Test4 \abc

The desired output is:

Test \ Test2 (linebreak) Test3 \n Test4 abc

One thing I've tried was:

str_replace(array('\\\\','\\n','\\'), array('\\',"\n",''), $str);

But that doesn't work, because it will run the replacing twice, which causes:

\\n

To be decoded as a linebreak anyway.

So I was thinking something like this:

$offset = 0;
$str = 'Test1 \\\\ Test2 \\n Test3 \\\\n Test4 \\abc';
while(($pos = strpos($str,'\\', $offset)) !== false) {

  $char = $str[$pos+1];
  if ($char=="n" || $char=="N") {
     // Insert a newline and eat 2 characters
     $str = substr($str,0,$pos-1) . "\n" . substr($str,$pos+2);
  } else {
     // eat slash
     $str = substr($str,0,$pos-1) . substr($str,$pos+1);
  }
  $offset=$pos+1;

}

This seems to work, but I was wondering if there's maybe a built-in that does exactly this and I completely missed it, or a better/more compact way altogether to do this.

Answer 1

stripcslashes() almost works, except that it won't recognize \a and skips it :(

$str = 'Test1 \\\\ Test2 \\n Test3 \\\\n Test4 \\abc';
echo stripcslashes($str);

outputs this...

Test1 \ Test2 
 Test3 \n Test4 bc