Charith's Blog: Regular Expressions

Showing posts with label Regular Expressions. Show all posts

Thursday, August 26, 2010

How to validate IP address using Regular expression

string exp = @"
    ^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.
     (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$";
string ipAddress = "127.0.0.1";
bool isMatch = Regex.IsMatch(ipAddress,exp);

Monday, August 16, 2010

How to validate file type with FileUpload control in asp.net using RegularExpression validator

Please note when you check a file type, remember to check of all the combination of letters. Example .Pdf, PDF, pdf, pdF, etc.
Example: Validate any pdf file

<%@ Page Language="C#" %>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <script runat="server"> 
        protected void Save(object sender, EventArgs e)
        {
            this.Page.Validate();
            if (this.IsValid)
            {
                if (this.fuPdfFile.HasFile && 
                    this.fuPdfFile.PostedFile.ContentType.ToLower().Equals("application/pdf"))
                {
 
                }
            }
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <asp:FileUpload runat="server" ID="fuPdfFile" />
            <asp:RegularExpressionValidator 
                runat="server"
                ID="rvafuPdfFile" 
                ControlToValidate="fuPdfFile" 
                ErrorMessage="Invalid File" 
                ValidationExpression="^.*\.([p|P][d|D][f|F])$" />
        </div>
        <asp:Button runat="server" ID="btnSave" OnClick="Save" Text="Save" />
    </form>
</body>
</html>

Tuesday, August 10, 2010

How to validate password strength using regular expression

Please note: code being formatted for the demonstration purposes.

<asp:TextBox runat="server" ID="txtMediumPassword" />
        <asp:RegularExpressionValidator runat="server" 
            ErrorMessage="Password should contain minimum 7 non repetitive characters" 
            ControlToValidate="txtMediumPassword" 
            ID="RegularExpressionValidator1" 
            ValidationExpression="^(?=.{7,})(((?=.*[A-Z])(?=.*[a-z]))|((?=.*[A-Z])(?=.*[0-9]))|((?=.*[a-z])(?=.*[0-9]))).*$" />
<asp:TextBox runat="server" ID="txtStrongPassword" />
<asp:RegularExpressionValidator runat="server" 
    ErrorMessage="
        Password should contain minimum 8 non repetitive characters, 
        at least 1 Uppercase character, at least 1 lowercase character and at least 1 digit." 
    ControlToValidate="txtStrongPassword"
    ID="regexPassword" 
    ValidationExpression="^(?=.{8,})(((?=.*[A-Z])(?=.*[a-z]))|((?=.*[A-Z])(?=.*[0-9]))|((?=.*[a-z])(?=.*[0-9])))(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9]).*$" />