Using preg match to find specific cluster of files

[shamuraq]

Hi guysm

I have a folder containing these files:

alg001.php
alg002.php
alg003.php
alg004.php
alg005.php
algComp.php
ranFrac.php
ranalg.php
randec.php
randint.php

I would only like to store the names of files alg001.php, alg002.php, alg003.php, alg004.php, alg005.php into an array. How do i achieve this with preg match?

[Barand]

Easier with str_starts_with()

$files = [  'alg001.php',
            'alg002.php',
            'alg003.php',
            'alg004.php',
            'alg005.php',
            'algComp.php',
            'ranFrac.php',
            'ranalg.php',
            'randec.php',
            'randint.php'
          ];
$required = array_filter($files, fn($v)=>str_starts_with($v, 'alg00'));
echo '<pre>' . print_r($required, 1) . '</pre>';

Gives

Array
(
    [0] => alg001.php
    [1] => alg002.php
    [2] => alg003.php
    [3] => alg004.php
    [4] => alg005.php
)

 

[shamuraq]

32 minutes ago, Barand said:

Easier with str_starts_with()

$files = [  'alg001.php',
            'alg002.php',
            'alg003.php',
            'alg004.php',
            'alg005.php',
            'algComp.php',
            'ranFrac.php',
            'ranalg.php',
            'randec.php',
            'randint.php'
          ];
$required = array_filter($files, fn($v)=>str_starts_with($v, 'alg00'));
echo '<pre>' . print_r($required, 1) . '</pre>';

Gives

Array
(
    [0] => alg001.php
    [1] => alg002.php
    [2] => alg003.php
    [3] => alg004.php
    [4] => alg005.php
)

 

I tried as suggested:

$arrFiles = array();
$dirPath = "./";
$files = scandir($dirPath);
$required = array_filter($files, fn($v)=>str_starts_with($v, 'alg00'));
echo '<pre>' . print_r($required, 1) . '</pre>';

The error:

Fatal error: Uncaught Error: Call to undefined function str_starts_with() ...php:29 Stack trace: #0 [internal function]: {closure}('.') #1 /...php(29): array_filter(Array, Object(Closure)) #2 {main} thrown in ...php on line 29

 

[Barand]

You must be using an outdated version of php. Str_starts_with() requires version 8.

Use this instead

$required = array_filter($files, fn($v)=>substr($v, 0, 5) == 'alg00');

 

[shamuraq]

14 minutes ago, Barand said:

You must be using an outdated version of php. Str_starts_with() requires version 8.

Use this instead

$required = array_filter($files, fn($v)=>substr($v, 0, 5) == 'alg00');

 

What does the values in 0,5 in substr($v, 0, 5) refers to?

Edited March 18 by shamuraq

[Barand]

Yes - the code I told you to use instead.

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