如何从文本文件中提取这些字符？

I have huge amount of code in a text file, for example:

"4EF\"]
,\"blue-apple\^&**%
"4EF\"]
,\"orange\/^4^&**%

How can I extract the following data:

blue-apple
orange

The data is between 4EF\"] ,\" and \ as you can see.

You could use preg_match_all() to get the part of the string you want:

$str = '"4EF\"]
,\"blue-apple\^&**%
"4EF\"]
,\"orange\/^4^&**%';

$str = preg_match_all('~^"4EF\\\\"[^"]+"([^\\\\]+)~m', $str, $matches);
print_r($matches[1]);

The regular expression will skip "4EF\" + all after the next ", then, use a capture group to keep all until the next backslash.

Or:

$str = '"4EF\"]
,\"blue-apple\^&**%
"4EF\"]
,\"orange\/^4^&**%';
$str = preg_match_all('~^"4EF\\\\"\]\\\
,\\\\"([^\\\\]+)~m', $str, $matches);
print_r($matches[1]);

Outputs:

Array
(
    [0] => blue-apple
    [1] => orange
)

The regular expression:

~          # delimiter
^          # indicate that the line begins by the following
"4EF       # sequence ("4EF)
\\\\       # a backslash
"          # a double quote
\]         # ']' need to be escaped 
\\\\       # a backslash
n,         # sequence (n,)
\\\\       # backslash
"          # double quote
(          # start capture group
  [^\\\\]+ # all characters until a backslash
)          # end capture group
~          # end delimiter
m          # multi line (to use ^)