Req #74449 [Dup]: Check string begins with function: str_begins()

From: Date: Sun, 16 Apr 2017 18:14:51 +0000
Subject: Req #74449 [Dup]: Check string begins with function: str_begins()
References: 1  Groups: php.bugs 
Request: Send a blank email to php-bugs+get-208602@lists.php.net to get a copy of this message
Edit report at https://bugs.php.net/bug.php?id=74449&edit=1

 ID:                 74449
 Updated by:         requinix@php.net
 Reported by:        stanislav dot eckert at vizson dot de
 Summary:            Check string begins with function: str_begins()
 Status:             Duplicate
 Type:               Feature/Change Request
 Package:            Strings related
 PHP Version:        Irrelevant
 Block user comment: N
 Private report:     N

 New Comment:

As is. Duplicate doesn't mean open or closed but that there is another bug/request already
being used to track the issue.

For the sake of automatic linkage: request #50434


Previous Comments:
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[2017-04-16 10:36:28] stanislav dot eckert at vizson dot de

strncmp() is quite good too, but it still requires manually setting a length value and it does not
seem to accept negative offsets (for str_end() like functionality). I understand, that this is not a
truly mandatory function - it just would be nice to have it. Low priority. 

Your link references are perfect! I didn't see that, thank you. Should I close the report now
or just leave it as is?

------------------------------------------------------------------------
[2017-04-16 06:34:13] requinix@php.net

See https://wiki.php.net/rfc/add_str_begin_and_end_functions
and the commentary in the PR https://github.com/php/php-src/pull/2049

By the way, have you seen http://php.net/manual/en/function.strncmp.php
?

------------------------------------------------------------------------
[2017-04-15 17:41:38] stanislav dot eckert at vizson dot de

Description:
------------
A quite often used code is to check if a string / binary string begins with a certain substring.
Using substr() requires setting 2nd param always to 0 and 3rd param to length, which is the often
set hardcoded or with strlen() / mb_strlen(). Example:

substr($str, 0, 7) == "http://"
// or
substr($str, 0, strlen("http://")) == "http://"

This can lead to errors, when user sets wrong length, mixes substr() & strlen() with their
multibyte versions, etc. A shorter version could be done with strpos() and checking for position 0,
but strpos() searches the entire string. RegEx has performance implications.

A simple function would result in a cleaner and a more robust and readable code. Example:

str_begins($str, $substr)  // => true / false

Its performance can also be optimized quite good, I think (compared to substr()).



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Edit this bug report at https://bugs.php.net/bug.php?id=74449&edit=1


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