Regular expression for validating directry path [duplicate] - php

$.validator.addMethod('AZ09_', function (value) {
return /^[a-zA-Z0-9.-_]+$/.test(value);
}, 'Only letters, numbers, and _-. are allowed');
When I use somehting like test-123 it still triggers as if the hyphen is invalid. I tried \- and --

Escaping using \- should be fine, but you can also try putting it at the beginning or the end of the character class. This should work for you:
/^[a-zA-Z0-9._-]+$/

Escaping the hyphen using \- is the correct way.
I have verified that the expression /^[a-zA-Z0-9.\-_]+$/ does allow hyphens. You can also use the \w class to shorten it to /^[\w.\-]+$/.
(Putting the hyphen last in the expression actually causes it to not require escaping, as it then can't be part of a range, however you might still want to get into the habit of always escaping it.)

The \- maybe wasn't working because you passed the whole stuff from the server with a string. If that's the case, you should at first escape the \ so the server side program can handle it too.
In a server side string: \\-
On the client side: \-
In regex (covers): -
Or you can simply put at the and of the [] brackets.

Generally with hyphen (-) character in regex, its important to note the difference between escaping (\-) and not escaping (-) the hyphen because hyphen apart from being a character themselves are parsed to specify range in regex.
In the first case, with escaped hyphen (\-), regex will only match the hyphen as in example /^[+\-.]+$/
In the second case, not escaping for example /^[+-.]+$/ here since the hyphen is between plus and dot so it will match all characters with ASCII values between 43 (for plus) and 46 (for dot), so will include comma (ASCII value of 44) as a side-effect.

\- should work to escape the - in the character range. Can you quote what you tested when it didn't seem to? Because it seems to work: http://jsbin.com/odita3

A more generic way of matching hyphens is by using the character class for hyphens and dashes ("\p{Pd}" without quotes). If you are dealing with text from various cultures and sources, you might find that there are more types of hyphens out there, not just one character. You can add that inside the [] expression

Related

preg_match for allowing letters, numbers and some special characters in PHP Preg_match() [duplicate]

$.validator.addMethod('AZ09_', function (value) {
return /^[a-zA-Z0-9.-_]+$/.test(value);
}, 'Only letters, numbers, and _-. are allowed');
When I use somehting like test-123 it still triggers as if the hyphen is invalid. I tried \- and --
Escaping using \- should be fine, but you can also try putting it at the beginning or the end of the character class. This should work for you:
/^[a-zA-Z0-9._-]+$/
Escaping the hyphen using \- is the correct way.
I have verified that the expression /^[a-zA-Z0-9.\-_]+$/ does allow hyphens. You can also use the \w class to shorten it to /^[\w.\-]+$/.
(Putting the hyphen last in the expression actually causes it to not require escaping, as it then can't be part of a range, however you might still want to get into the habit of always escaping it.)
The \- maybe wasn't working because you passed the whole stuff from the server with a string. If that's the case, you should at first escape the \ so the server side program can handle it too.
In a server side string: \\-
On the client side: \-
In regex (covers): -
Or you can simply put at the and of the [] brackets.
Generally with hyphen (-) character in regex, its important to note the difference between escaping (\-) and not escaping (-) the hyphen because hyphen apart from being a character themselves are parsed to specify range in regex.
In the first case, with escaped hyphen (\-), regex will only match the hyphen as in example /^[+\-.]+$/
In the second case, not escaping for example /^[+-.]+$/ here since the hyphen is between plus and dot so it will match all characters with ASCII values between 43 (for plus) and 46 (for dot), so will include comma (ASCII value of 44) as a side-effect.
\- should work to escape the - in the character range. Can you quote what you tested when it didn't seem to? Because it seems to work: http://jsbin.com/odita3
A more generic way of matching hyphens is by using the character class for hyphens and dashes ("\p{Pd}" without quotes). If you are dealing with text from various cultures and sources, you might find that there are more types of hyphens out there, not just one character. You can add that inside the [] expression

Differences between two regular expressions

Do anybody know why this regex:
/^(([a-zA-Z0-9\(\)áéíóúÁÉÍÓÚñÑ,\.°-]+ *)+)$/
works but this one doesn't:
/^(([a-zA-Z0-9áéíóúÁÉÍÓÚñÑ,\.°-\(\)]+ *)+)$/
The difference is the place where the parenthesis are... I tryed with some online PHP regex testers and got the same result. The second one simply doesn't work...
PHP returns:
preg_match(): Compilation failed: range out of order in character class at offset 44 in...
This is not a critic question because I've managed to make it work but I have the curiosity!
Maybe the unicode characters are changing something?
When the - character is used inside of brackets (indicating a character set) it indicates a range unless it is the last character in the set, first character in the set, or directly after the opening negating character. Then it means a literal dash. By moving it from the end to the middle you changed its meaning. If you want to keep it in the middle you will need to escape it: \-.
If the hyphen is placed as the first or last character in the character class, it is treated as a literal - (as opposed to a range), and as a result do not require escaping.
These are the positions where the hyphen do not need to be escaped:
right after the opening bracket ([), or
right before the closing bracket (]), or
right after the negating caret (^)
In the second regular expression, you're placing the hyphen in the middle, and the regular expression engine tries to create a range with the character before the hyphen, the character after the hyphen, and all characters that lie between them in numerical order. As such a range isn't possible, an error message is triggered. See asciitable.com for the character table.
Putting the hyphen last in the expression actually causes it to not require escaping, as it then can't be part of a range, however you might still want to get into the habit of always escaping it.
At your first regex you've managed every thing correctly even that - hyphen which is at the end of it. well it should be there too! I mean it has two places if you don't want to escape it, one place is at the end of char class and the other one at the beginning of char class!
You guessed nice! otherwise you should escape it!

allow parentheses and other symbols in regex

I've made this regex:
^[a-zA-Z0-9_.-]*$
Supports:
letters [uppercase and lowercase]
numbers [from 0 to 9]
underscores [_]
dots [.]
hyphens [-]
Now, I want to add these:
spaces [ ]
comma [,]
exclamation mark [!]
parenthesis [()]
plus [+]
equal [=]
apostrophe [']
double quotation mark ["]
at [#]
dollar [$]
percent [%]
asterisk [*]
For example, this code accept only some of the symbols above:
^[a-zA-Z0-9 _.,-!()+=“”„#"$#%*]*$
Returns:
Warning: preg_match(): Compilation failed: range out of order in character class at offset 16
Make sure to put hyphen - either at start or at end in character class otherwise it needs to be escaped. Try this regex:
^[a-zA-Z0-9 _.,!()+=`,"#$#%*-]*$
Also note that because * it will even match an empty string. If you don't want to match empty strings then use +:
^[a-zA-Z0-9 _.,!()+=`,"#$#%*-]+$
Or better:
^[\w .,!()+=`,"#$#%*-]+$
TEST:
$text = "_.,!()+=,#$#%*-";
if(!preg_match('/\A[\w .,!()+=`,"#$#%*-]+\z/', $text)) {
echo "error.";
}
else {
echo "OK.";
}
Prints:
OK.
The hyphen is being treated as a range marker -- when it sees ,-! it thinks you're asking for a range all characters in the charset that fall between , and ! (ie the same way that A-Z works. This isn't what you want.
Either make sure the hyphen is the last character in the character class, as it was before, or escape it with a backslash.
I would also point out that the quote characters you're using “”„ are part of an extended charset, and are not the same as the basic ASCII quotes "'. You may want to include both sets in your pattern. If you do need to include the non-ASCII characters in the pattern, you should also add the u modifier after the end of your pattern so it correctly picks up unicode characters.
Try escaping your regex: [a-zA-Z0-9\-\(\)\*]
Check if this help you: How to escape regular expression special characters using javascript?
Inside of a character class [...] the hyphen - has a special meaning unless it is the first or last character, so you need to escape it:
^[a-zA-Z0-9 _.,\-!()+=“”„#"$#%*]*$
None of the other characters need to be escaped in the character class (except ]). You will also need to escape the quote indicating the string. e.g.
'/[\']/'
"/[\"]/"
try this
^[A-Z0-9][A-Z0-9*&!_^%$#!~#,=+,./\|}{)(~`?][;:\'""-]{0,8}$
use this link to test
trick is i reverse ordered the parenthesis and other braces that took care of some problems. And for square braces you must escape them

Help with php regex for limiting allowed characters

I'm working in php and want to set some rules for a submitted text field. I want to allow letters, numbers, spaces, and the symbols # ' , -
This is what I have:
/^(a-z,0-9+# )+$/i
That seems to work but when I add the ' or - symbols I get errors.
Almost there. What you're looking for is called character classes. These are denoted by the use of square brackets. For example
/^[-a-z0-9+#,' ]+$/i
To include the hyphen character, it needs to be the first or last character in the class.
Edit
As you want to include the single quote and you're using PHP where regular expressions must be represented as strings, be careful with how you quote the pattern. In this case, you can use either of
$pattern = "/^[-a-z0-9+#,' ]+\$/i"; // or
$pattern = '/^[-a-z0-9+#,\' ]+$/i';
You should use a character class - [a-zA-Z0-9 #',-]
Note that - should be used first or last or escaped otherwise it gets treated as denoting a range and you will get errors
I want to allow letters, numbers, spaces, and the symbols #, ', , and -.
Use this regex...
/^[-a-zA-Z\d ',#]+\z/
Note the \z. If you use $, you are allowing a trailing \n. CodePad.
Ensure to escape the ' if you are using ' as your string delimiter.
Please use /^[a-z,0-9+\#\-,\s]+$/i
Use this regex:
/^[-a-z0-9,# ']+$/i

How bad is my regex?

Ok so I managed to solve a problem at work with regex, but the solution is a bit of a monster.
The string to be validated must be:
zero or more: A-Z a-z 0-9, spaces, or these symbols: . - = + ' , : ( ) /
But, the first and/or last characters must not be a forward slash /
This was my solution (used preg_match php function):
"/^[a-z\d\s\.\-=\+\',:\(\)][a-z\d\s\.\-=\+\',\/:\(\)]*[a-z\d\s\.\-=\+\',:\(\)]$|^[a-z\d\s\.\-=\+\',:\(\)]$/i"
A colleague thinks this is too big and complicated. Well it works, so is it really that bad? Anyone in the mood for some regex-golf?
You can simplify your expression to this:
/^(?:[a-z\d\s.\-=+',:()]+(?:/+[a-z\d\s.\-=+',:()]+)*)?$/i
The outer (?:…)? is to allow an empty string. The [a-z\d\s.\-=+',:()]+ allows to start with one or more of the specified characters except the /. If a / follows, it also must be followed by one or more of the other specified characters ((?:/[a-z\d\s.\-=+',:()]+)*).
Furthermore, inside a character set, you only need to escape the characters \, ], and depending on the position also ^ and -.
Try something like this instead
function validate($string) {
return (preg_match("/[a-zA-Z0-9.\-=+',:()/]*/", $string) && substr($string, 0,1) != '/' && substr($string, -1) != '/'))
}
It's a lot simpler to check the first and last character specifically. Otherwise you're left with dealing with a lot of overhead when it comes to empty strings and such. Your regex, for example, requires the string to be at least one character long, otherwise it doesn't validate. Despite "" fitting your criteria.
'#^(?!/)[a-z\d .=+\',:()/-]*$(?<!/)#i'
As others have observed, most of those characters don't need to be escaped inside a character class. Additionally, the hyphen doesn't need to be escaped if it's the last thing listed, and the slash doesn't need to be escaped if you use a different character as the regex delimiter (# in this case, but ~ is a popular choice, too).
I also ditched the double-quotes in favor of single-quotes, which meant I had to escape the single-quote in the regex. That's worth it because single-quoted strings are so much simpler to work with: no $variable interpolation, no embedded executable {code}, and the only characters you have to escape for them are the single-quote and the backslash.
But the main innovation here is the use of lookahead and lookbehind to exclude the slash as the first or last character. That's not just a code-golf tactic, either; I would write the regex this way anyway, because it expresses my intent so much better. Why force the next guy to parse those almost-identical character classes, when you can just say what you mean? "...but the first and last character can't be slashes."

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