CODEWITHSUNDEEP
phpregex
Sergey Scopin
Sergey Scopin

Reputation: 2245

preg_replace issue. Character class inside other character class

I have a fragment in text like

;flat
CID_999999 = 99999999
CID_999999 = 99999999
CID_999999 = 99999999
CID_999999 = 99999999

where 999999 are some numbers. I want to find this fragment by regexp. When I use this regex:

preg_replace('/;flat[\s\r\n]+[CID_0-9]+\s=\s[0-9]+\n/','REPLACEMENT',$content);

it replaces ;flat and first CID string. So, I suppose that if I put [CID_0-9]+\s=\s[0-9]+\n part in character class []+it will remove all CID strings. But if I do it it doesn't replace anything. So I don't understand something in regex. What am I doing wrong? I thought that expected output is clear, but ok. I should replace all fragment by REPLACEMENT.

Upvotes: 0

Views: 57

Answers (3)

elixenide
elixenide

Reputation: 44831

You don't need a character class ([...]); you need a group ((...)). Your code should look like this:

preg_replace('/;flat[\s\r\n]+([CID_0-9]+\s=\s[0-9]+\n?)+/', 'REPLACEMENT', $content);

Note the ? at the end, just in case your last line isn't terminated with a new line (\n) character.

Demo

Upvotes: 0

vks
vks

Reputation: 67968

;flat\s*|(?!^)\G(CID_\d+\s*=\s*\d+\s*)

Try this.Replace by $1.See demo.

https://regex101.com/r/gQ3kS4/7

$re = "/;flat\\s*|(?!^)\\G(CID_\\d+\\s*=\\s*\\d+\\s*)/";
$str = ";flat\nCID_999999 = 99999999\nCID_999999 = 99999999\nCID_999999 = 99999999\nCID_999999 = 99999999\n;";
$subst = "$1";

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

Upvotes: 0

RobP
RobP

Reputation: 9522

  1. Use lookbehind if you are trying to match just the digits after the = and before the newline

  2. For more accurate matching use CID[0-9]+ rather than [CID0-9]+

    preg_replace('/(?<;flat[\s\r\n]+CID_[0-9]+\s=\s)[0-9]+(?=\n)/','REPLACEMENT',$content);

Upvotes: 1

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