get number from file with regexp? - php

Question

I've got files named
1234_crob.jpg
1234.jpg
2323_örja.bmp
2323.bmp
etc.
How can I just retrieve numbers e.g. 1234 and 2323?

Answer 1

If the file names all start with numbers there is no need to use regular expressions, try this instead:
foreach (glob('/path/to/dir/{0,1,2,3,4,5,6,7,8,9}*', GLOB_BRACE) as $file)
{
echo $file . ' = ' . intval(basename($file)) . "<br />\n";
}
This updated glob pattern will only match filenames that start with a digit, as you requested.
#ghostdog74: You're right.
foreach (glob('/path/to/dir/{0,1,2,3,4,5,6,7,8,9}*', GLOB_BRACE) as $file)
{
echo $file . ' = ' . filter_var(basename($file), FILTER_SANITIZE_NUMBER_INT) . "<br />\n";
}

Answer 2

First explode on the period, and then explode on the underscore, and then your number is the first element in the returned list.
<?php
$str1 = "1234.jpg";
$str2 = "1234_crob.jpg";
$pieces = explode("_",current(explode(".",$str1)));
echo $pieces[0]; // prints 1234
$pieces = explode("_",current(explode(".",$str2)));
echo $pieces[0]; // prints 1234
?>
Yes, I realize this is not a regular expression, but this is too simple a task to use regular expressions.
EDIT: Modified code to work for your newly edited formatting examples.
EDIT: Modified to fit cleanly in one line of code.

Answer 3

Assuming you only pass in filenames (and not filepaths), the following should retrieve all consecutive numbers 0-9:
function getDigits($fn) {
$arr = array();
preg_match('/[0-9]+/', $fn, $arr);
return $arr;
}
EXAMPLE USAGE
var_dump(getDigits('hey_12345.gif'));
/*
output:
array(1) {
[0]=>
string(5) "12345"
}
*/
var_dump(getDigits('123487_dude.jpg'));
/*
output:
array(1) {
[0]=>
string(6) "123487"
}
*/

Answer 4

try this. If you have numbers like 045_test.jpg, using intval will give you 45 instead of 045
$path="/path/[0-9]*";
foreach (glob($path) as $files ){
$base=basename ($files);
$s = preg_split("/[^0-9]/",$base,2);
echo $s[0]."\n";
}