[RESOLVED] Validation in php

@esquiladoFeb 18.2010

Php validation

if(!preg_match(‘^{^[a-zA-Z]+$’,$_POST[‘username’]))}

I want to make it that $_POST[‘username’] can ~~[B]~~only[/B] consist of letters A-Za-z, however, don’t know how. What I am trying to make is an if() statment that checks if the string $_POST[‘username’] does not only consist of letters hence the use of the ! before the preg_match statement.

I don’t know how to do this, I am very new to php and would like some help, this error message is coming up:

Warning: preg_match() [function.preg-match]: No ending delimiter ‘^{^‘} found in

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19 Comments(s) _↴

@SrWebDeveloperFeb 18.2010 — #

[code=php]if(!preg_match('/^[a-zA-Z]+$/',$_POST['username'])) {print "invalid username";} else {print "valid username";}[/code]

If you wish to allow a space in the username as well, just add s after the upper case Z.

-jim

@esquiladoauthorFeb 18.2010 — #Thanks, If I allow a space, will the user be allowed to [I]only[/I] use spaces, with no text, I wouldn't mind allowing a space in the middle of the name, but I don't want to only allow spaces.

@esquiladoauthorFeb 18.2010 — #And I don't want them to be able to end the name with a space.

@NogDogFeb 18.2010 — #You could first trim() the value to remove leading and trailing spaces.

@esquiladoauthorFeb 18.2010 — #Oh ok, thanks.

@esquiladoauthorFeb 18.2010 — #How do I count how many characters are in a string? Because I could use trim(), and then after that do a check that the string has got at least two characters.

@criterion9Feb 18.2010 — #strlen($string) gives you the length of a string.

@esquiladoauthorFeb 18.2010 — #Thanks =)

@iandevlinFeb 18.2010 — #thestring.length

@criterion9Feb 18.2010 — #thestring.length[/QUOTE]

That is java/javascript syntax. It won't work in PHP.

@iandevlinFeb 18.2010 — #That is java/javascript syntax. It won't work in PHP.[/QUOTE]

Ah crap, I thought he was on about JavaScript for some reason. My mistake!

@criterion9Feb 18.2010 — #Lol. I do that sometimes too. I just wanted to make sure to clarify so anyone following the thread wouldn't be confused.

@iandevlinFeb 18.2010 — #Lol. I do that sometimes too. I just wanted to make sure to clarify so anyone following the thread wouldn't be confused.[/QUOTE]

Sure, no worries! ?

@esquiladoauthorFeb 18.2010 — #I want to learn javascript, so I'll keep a mental note of that =)

@SrWebDeveloperFeb 18.2010 — #Man, this thread got busy fast.

Just for a second, going back to the original issue:

[code=php]$_POST['username']=preg_replace("/[s]{2,}/"," ",trim($_POST['username']));[/code]

When the above code is added [U]after[/U] the expression I gave you earlier, after all is said and done, a username can only be alphabetical, no spaces on the front or the end, and [COLOR=Red]no more than 1 space in the middle[/COLOR] if spaces are found. ?

If someone feels like merging it all into one expression, go for it, but the user has something to work with now if they end up permitting a space in a username.

-jim

@esquiladoauthorFeb 18.2010 — #

[code=php]if(!preg_match('/^[a-zA-Z]+$/',$_POST['username']))
 
   {
   echo "Only letters can be entered into this field, no spaces, special characters or numbers are permitted. Please try again.";
   }
  elseif((mysql_num_rows(mysql_query("SELECT ipadd FROM members WHERE ipadd = '$ipadd'")))==0)
  {
   $trimUname = trim($_POST['username']);
   if(strlen($trimUname < 2))
   {
   echo "Your name must consist of at least two characters.";
   }
   else
   {
   $dUsername = @$_POST['username'];
   $timenow = time();
   mysql_query("INSERT INTO members (ipadd,username,timeJoined) VALUES ('$ipadd','$dUsername','$timenow')");
   echo "<br>You have now been added to the database.";
   }
  }[/code]

Thank you, so where would I put that in this code?

@SrWebDeveloperFeb 18.2010 — #If you opt to allow a space after all (hey, it was just a suggestion above, it's not required) I'd personally rework that entire section. I prefer to do all the validation/formatting once in a function to centralize the code (see code comments below), then do all the query stuff after.

That's just me.

Example (not your code, just to demonstrate the concept, tested/works):

[code=php]$username=ValidateUserName($_POST['username']);
 if (!$username) {print "Only alphabetical case insensitive characters and an optional single space are allowed!";}
 else { 
 //... rest of your code ...
 print "Welcome, $username...";
 }
 
 function ValidateUserName($myusername) {
 
  $myusername=preg_replace("/[s]{2,}/"," ",trim($myusername));
  if(!preg_match('/^[a-zA-Zs]+$/',$myusername)) {
   return false;
  }
 
  /* If necessary in the future add more tests here if username
   policy changes.  Just return false if any test fails.
   Otherwise, username is valid, let's return that value. */
 
 return $myusername;
 }
 [/code]

To each their own. I've done all I can do here, gotta scoot. Cya! ?

-jim

@SrWebDeveloperFeb 18.2010 — #Shoot, forgot to clarify, I meant no more than one [U]consecutive[/U] space allowed. This allows usernames like "John R Brown". If you want to limit it to one space total, just throw in another condition in my function that counts how many spaces in the string and return false if >1 and re-word the invalid username message I display to the user, duh. >poof< I'm gone!

-jim

@esquiladoauthorFeb 19.2010 — #Thank you ever so much!! I did the one above, where it disallows consecutive spaces, but didn't do the second one =).

[B]Thank you!!!![/B]

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