Replace and Remove character at the same time using regular expression

Question

I want to remove all the illegal character and replace the space with underscore so i use this code:

function sanitize_file_name($filename) {
    $filename = preg_replace("/([^A-Za-z0-9_\-\.]|[\.]{2})/", "", $filename);
    return basename($filename);
}

for example i have a filename like "www..//../no way" when i sanitize it, it become 'wwwno_way'.

it work to remove the other character that i want but the problem is i don't know how to replace the space with underscore at the same time using preg_replace. Is it posible? and how i can accomplish it?

please check this: https://stackoverflow.com/questions/14114411/remove-all-special-characters-from-a-string — Diego Avila, Jun 08 '18 at 15:03
Use preg_replace_callback(): http://php.net/manual/en/function.preg-replace-callback.php — CSSBurner, Jun 08 '18 at 15:05
@Tegito123 thanks, i know how to replace using 2 regex but is it possible just using 1 regular expression to accomplish it? — Ying, Jun 08 '18 at 15:05
`$filename = str_replace(' ', '_', preg_replace('/[^\w.]|\.{2}/', '', $filename));` — anubhava, Jun 08 '18 at 15:05
No that is not possible, unless you use a callback but that will be slower than using a separate, plain (non-regex) replace just for those spaces. — trincot, Jun 08 '18 at 15:06
ah ok i guess i have to use two regex. thanks. @anubhava it still not work. — Ying, Jun 08 '18 at 15:11
You don't need a regex to replace spaces, `str_replace` will do it. `str_replace(' ', '_', $string)` — user3783243, Jun 08 '18 at 15:13
@user3783243 well i need regex to replace other character not just space. — Ying, Jun 08 '18 at 15:15
Yes, but you said you'll need 2 regexs, you actually only need 1. Replace the characters, then replace the spaces. — user3783243, Jun 08 '18 at 15:15
yep i think i will use the string replace for the other one. seem like there is no way i can get just by one regex. silly me. — Ying, Jun 08 '18 at 15:17
@CasimiretHippolyte ah sorry i missed but in my real code it already removed. — Ying, Jun 08 '18 at 15:20

score 0 · Answer 1 · answered Jun 08 '18 at 15:09

0

In preg_replace() function the second param is the param you want to get replaced with.

function sanitize_file_name($filename) {
$filename = preg_replace("/([^A-Za-z0-9_\-\.]|[\.]{2})/", "_", $filename);
return basename($filename);
}

answered Jun 08 '18 at 15:09

webshifu

155
7

it make $text = 'www..//../no way'; into www_____no_way. which it suppose just www_no_way. – Ying Jun 08 '18 at 15:13
it is because the preg_replace is replacing every illegal character with the "_", if you want only spaces to be replaced with "_" then you'll have to use the str_replace in the final return statement after preg_replace. – webshifu Jun 08 '18 at 15:17
yes that is why i'm asking is it posible to use single regex to remove space and replace other character with ''. – Ying Jun 08 '18 at 15:19

Replace and Remove character at the same time using regular expression

1 Answers1