Re: question about preg_replace

From	Lew Pitcher <lew.pitcher@digitalfreehold.ca>
Newsgroups	comp.lang.php
Subject	Re: question about preg_replace
Date	2022-02-23 21:02 +0000
Organization	A noiseless patient Spider
Message-ID	<sv67d0$k2d$5@dont-email.me> (permalink)
References	<sv5hv3$h8m$2@gioia.aioe.org> <sv5kqr$k2d$1@dont-email.me>

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On Wed, 23 Feb 2022 15:45:31 +0000, Lew Pitcher wrote:

> On Wed, 23 Feb 2022 15:56:35 +0100, alex wrote:
> 
>> $ echo center | sed -E 's#(.*)#start-\1-end#'
>> start-center-end
>> 
>> I tried to do the same thing with php, but the result is different
>> 
>> $ php -r "echo preg_replace('#(.*)#', 'start-\0-end', 'center') .
>> PHP_EOL;"
>> start-center-endstart--end
>>                  ^^^^^^^^^^
>> 
>> Why?

[snip]

> You have a couple of possible changes that you can apply to bring your
> PHP closer to sed(1):
> 1) you can limit your RE to one occurrence:
>    preg_replace('#(.*)#', 'start-\0-end', 'center',1)
> 
> or
> 
> 2) you can anchor your RE to the start of the string:
>    preg_replace('#^(.*)#', 'start-\0-end', 'center')
>    preg_replace('#(^.*)#', 'start-\0-end', 'center')

You could also change the RE so that it matches ONE OR MORE characters,
preventing it from matching the empty string at the end of the data.
    preg_replace('#(.+)#', 'start-\0-end', 'center')



-- 
Lew Pitcher
"In Skills, We Trust"

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Thread

question about preg_replace alex <1j9448a02@lnx159sneakemail.com.invalid> - 2022-02-23 15:56 +0100
  Re: question about preg_replace Mateusz Viste <mateusz@xyz.invalid> - 2022-02-23 16:33 +0100
    Re: question about preg_replace alex <1j9448a02@lnx159sneakemail.com.invalid> - 2022-02-23 16:45 +0100
      Re: question about preg_replace Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-02-23 15:49 +0000
        Re: question about preg_replace Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-02-23 15:51 +0000
          Re: question about preg_replace alex <1j9448a02@lnx159sneakemail.com.invalid> - 2022-02-23 20:10 +0100
      Re: question about preg_replace Mateusz Viste <mateusz@xyz.invalid> - 2022-02-23 18:06 +0100
        Re: question about preg_replace alex <1j9448a02@lnx159sneakemail.com.invalid> - 2022-02-23 20:14 +0100
  Re: question about preg_replace Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-02-23 15:45 +0000
    Re: question about preg_replace alex <1j9448a02@lnx159sneakemail.com.invalid> - 2022-02-23 20:19 +0100
    Re: question about preg_replace Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-02-23 21:02 +0000

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