I would like you to help define my preg_match .
This will be for the creation of a form textarea $_POST['text'] .
I want pregmatch to just accept: Traces, Dots, Bars, + and -, commas, spaces, numbers, letters, # and *.
preg_replace("", $data);
If you understand, you want the preg_match to validate if it contains only the following character types:
+
-
# (hash) * (asterisk) You can use the following regex :
^[a-z0-9\-+, .\#*\/]+$
No preg_match would be:
if (empty($_POST['text'])) {
echo 'Não digitou nada';
} else {
$text = $_POST['text'];
if (preg_match('#^[a-z0-9\-+, .\#*\/]+$#i', $text)) {
echo 'Validou';
} else {
echo 'Não validou';
}
}
This regex is very simple:
[...] keys and everything inside will be accepted (will match) ^ sign indicates that it should begin exactly with the following expression $ indicates that it should end exactly with the previous expression + between ] and $ ( ...]+$ ) indicates that it should have the format of what it has within [...] until it finds the next expression, since it has no expression, only $ then ends there, (regardless of the number of characters) Extra explanations:
a-z indicates that it can contain from A to Z \d indicates that it can contain 0 to 9 (is equivalent to typing 0-9 ) \- indicates that it may contain hyphens ( - ), the bar is to escape and not mix with any shortcut \ is to accept backslashes, use two bars so that regex does not think you are trying to escape the next expression i in #...#i is to consider both uppercase and lowercase ^[a-z\d\-+, .\#*\/]+$
^ ^ ^^
. . ..
. . .... Termina exatamente com a expressão anterior
. . .
. . .... busca até o "final" ou até a próxima expressão
. .
. ..................... tudo que estiver dentro de '[...]' será valido
.
........................ deve começar exatamente com a próxima expressão