validating username

[Sudhakar]

i have used the following code to validate the username it is working
fine

=============== =============== ===============
if( $username == "" || !preg_match("/^[a-z0-9]+(?:_[a-z0-9]+)?$/i",
$username) )
{
$error.="User name cannot be blank or has special characters";
}
=============== =============== ===============

it does not accept UNDERSCORE at the beginning or end however while i
was testing with different special characters except for # the
validation works fine for all other special characters.

for example if i enter the user name as = abc#123

in this case # sign and what comes after # sign is being ignored. so
in this case the username is being read as abc ONLY and not abc#123

this is very strange, how can i still validate # sign and tell the
user that # sign is not a valid username like i have been doing with
any other special characters like = !@$...........

please advice.

thanks.

[Michael Fesser]

Re: validating username

..oO(Sudhakar)

>i have used the following code to validate the username it is working
>fine
>
>============== =============== =============== =
>if( $username == "" || !preg_match("/^[a-z0-9]+(?:_[a-z0-9]+)?$/i",
>$username) )
>{
>$error.="Use r name cannot be blank or has special characters";
>}
>============== =============== =============== =
>
>it does not accept UNDERSCORE at the beginning or end however while i
>was testing with different special characters except for # the
>validation works fine for all other special characters.
>
>for example if i enter the user name as = abc#123
>
>in this case # sign and what comes after # sign is being ignored. so
>in this case the username is being read as abc ONLY and not abc#123

Ignored by whom? Does $username contain the full name including the '#'?
Then preg_match() shouldn't have a problem with it.

Micha

[Curtis]

Re: validating username

Sudhakar wrote:

i have used the following code to validate the username it is working
fine
>
=============== =============== ===============
if( $username == "" || !preg_match("/^[a-z0-9]+(?:_[a-z0-9]+)?$/i",
$username) )
{
$error.="User name cannot be blank or has special characters";
}
=============== =============== ===============
>
it does not accept UNDERSCORE at the beginning or end however while i
was testing with different special characters except for # the
validation works fine for all other special characters.
>
for example if i enter the user name as = abc#123
>
in this case # sign and what comes after # sign is being ignored. so
in this case the username is being read as abc ONLY and not abc#123
>
this is very strange, how can i still validate # sign and tell the
user that # sign is not a valid username like i have been doing with
any other special characters like = !@$...........
>
please advice.
>
thanks.

Use \w, it's locale-specific, and includes underscore. It's simply:

preg_match('/^\w+$/', $string);

I'm not sure if this is what you meant.

--
Curtis

[Michael Fesser]

Re: validating username

..oO(Sudhakar)

>On May 26, 3:13 pm, Michael Fesser <neti...@gmx.de wrote:

>>
>Ignored by whom? Does $username contain the full name including the '#'?
>Then preg_match() shouldn't have a problem with it.

>
>thanks for replying. i have looked at the process and realised that i
>am using GET method. following is the page sequence.
>
>first page = register.php here a user enters a username and clicks on
>an image to find out if the username is available or
>
>not. using a javascript function of onclick i am reading the value
>entered in the form in javascript as
>============== =============== =============== =
>var useri = document.regist rationform.user name
>var valueofuseri = document.regist rationform.user name.value
>
>var recui = /^\s{1,}$/g;
>
>if ((useri.value== null) || (useri.value==" ") || (useri.length== "") ||
>(useri.value.s earch(recui))-1)
>{
>alert("Pleas e Enter a User Name")
>return false
>}
>
>window.open("c heckusernamei.p hp?theusernamei s="+valueofuser i,
>"titleforavail abilityi", "width=680, height=275, status=1,
>
>scrollbars=1 , resizeable=yes" );

What happens if there's no JS available or not enabled on the client?
Is there another server-side check?

Anyway, your JavaScript causes the problem. If the user name contains a
"#" like in "foo#bar" for example, you'll end up with a URL like this:

checkusernamei. php?theusername is=foo#bar

But the '#' separates a URL from a fragment identifier, so all the
server will see here is just "checkusernamei .php?theusernam eis=foo".

If such special chars are allowed in user names, you have to URL-encode
them. In a normal form submission the browser does this automatically,
but here you have to do it manually. Maybe there's already a JS function
available for that, I don't know.

Micha

[Sudhakar]

Re: validating username

On May 28, 4:36 pm, Michael Fesser <neti...@gmx.de wrote:

.oO(Sudhakar)
>
>
>

On May 26, 3:13 pm, Michael Fesser <neti...@gmx.de wrote:

>

Ignored by whom? Does $username contain the full name including the '#'?
Then preg_match() shouldn't have a problem with it.

>

thanks for replying. i have looked at the process and realised that i
am using GET method. following is the page sequence.

>

first page = register.php here a user enters a username and clicks on
an image to find out if the username is available or

>

not. using a javascript function of onclick i am reading the value
entered in the form in javascript as
=============== =============== ===============
var useri = document.regist rationform.user name
var valueofuseri = document.regist rationform.user name.value

>

var recui = /^\s{1,}$/g;

>

if ((useri.value== null) || (useri.value==" ") || (useri.length== "") ||
(useri.value.se arch(recui))-1)
{
alert("Please Enter a User Name")
return false
}

>

window.open("ch eckusernamei.ph p?theusernameis ="+valueofuseri ,
"titleforavaila bilityi", "width=680, height=275, status=1,

>

scrollbars=1, resizeable=yes" );

>
What happens if there's no JS available or not enabled on the client?
Is there another server-side check?
>
Anyway, your JavaScript causes the problem. If the user name contains a
"#" like in "foo#bar" for example, you'll end up with a URL like this:
>
checkusernamei. php?theusername is=foo#bar
>
But the '#' separates a URL from a fragment identifier, so all the
server will see here is just "checkusernamei .php?theusernam eis=foo".
>
If such special chars are allowed in user names, you have to URL-encode
them. In a normal form submission the browser does this automatically,
but here you have to do it manually. Maybe there's already a JS function
available for that, I don't know.
>
Micha

thanks for replying. javascript is able to read with the # sign, so
should i use url-encode in javascript or in php. please advice.

[AnrDaemon]

Re: validating username

Greetings, Sudhakar.
In reply to Your message dated Thursday, May 29, 2008, 23:55:03,

>Ignored by whom? Does $username contain the full name including the '#'?
>Then preg_match() shouldn't have a problem with it.

>>

>thanks for replying. i have looked at the process and realised that i
>am using GET method. following is the page sequence.

>>

>first page = register.php here a user enters a username and clicks on
>an image to find out if the username is available or

>>

>not. using a javascript function of onclick i am reading the value
>entered in the form in javascript as
>============== =============== =============== =
>var useri = document.regist rationform.user name
>var valueofuseri = document.regist rationform.user name.value

>>

>var recui = /^\s{1,}$/g;

>>

>if ((useri.value== null) || (useri.value==" ") || (useri.length== "") ||
>(useri.value.s earch(recui))-1)
>{
>alert("Pleas e Enter a User Name")
>return false
>}

>>

>window.open("c heckusernamei.p hp?theusernamei s="+valueofuser i,
>"titleforavail abilityi", "width=680, height=275, status=1,

>>

>scrollbars=1 , resizeable=yes" );

>>
>What happens if there's no JS available or not enabled on the client?
>Is there another server-side check?
>>
>Anyway, your JavaScript causes the problem. If the user name contains a
>"#" like in "foo#bar" for example, you'll end up with a URL like this:
>>
>checkusernamei .php?theusernam eis=foo#bar
>>
>But the '#' separates a URL from a fragment identifier, so all the
>server will see here is just "checkusernamei .php?theusernam eis=foo".
>>
>If such special chars are allowed in user names, you have to URL-encode
>them. In a normal form submission the browser does this automatically,
>but here you have to do it manually. Maybe there's already a JS function
>available for that, I don't know.

thanks for replying. javascript is able to read with the # sign, so
should i use url-encode in javascript or in php. please advice.

You'd better use POST method instead of GET, but if GET is absolutely
required, encode data before sending to server.


--
Sincerely Yours, AnrDaemon <anrdaemon@free mail.ru>