HTTP protocol is a stateless protocol. For a commercial website, it is required to maintain session information among different pages. For example, one user registration ends after completing many pages. How to maintain user's session information across all the web pages?In many situations, using cookies is the most efficient method ... Read More

Drop Down Box is used when we have many options available but only one or two will be selected.ExampleHere is example HTML code for a form with one drop down box − Maths Physics OutputThe result of this code is the following form −Below is dropdown.py script ... Read More

Radio Buttons are used when only one option is required to be selected.ExampleHere is example HTML code for a form with two radio buttons − Maths Physics The result of this code is the following form −Below is radiobutton.py script to handle input given by web browser ... Read More

TEXTAREA element is used when multiline text has to be passed to the CGI Program.ExampleHere is example HTML code for a form with a TEXTAREA box − Type your text here... The result of this code is the following form −Below is textarea.cgi script to handle input ... Read More

Checkboxes are used when more than one option is required to be selected.ExampleHere is example HTML code for a form with two checkboxes − Maths Physics OutputThe result of this code is the following form −Below is checkbox.cgi script to handle input given by web browser for ... Read More

A generally more reliable method of passing information to a CGI program is the POST method. This packages the information in exactly the same way as GET methods, but instead of sending it as a text string after a ? in the URL it sends it as a separate message. ... Read More

The GET method sends the encoded user information appended to the page request. The page and the encoded information are separated by the ? character as follows −http://www.test.com/cgi-bin/hello.py?key1=value1&key2=value2The GET method is the default method to pass information from browser to web server and it produces a long string that appears ... Read More

Literal charactersSr.No.Example & Description1pythonMatches beginning of line.Character classesSr.No.Example & Description1[Pp]ythonMatch "Python" or "python"2rub[ye]Match "ruby" or "rube"3[aeiou]Match any one lowercase vowel4[0-9]Match any digit; same as [0123456789]5[a-z]Match any lowercase ASCII letter6[A-Z]Match any uppercase ASCII letter7[a-zA-Z0-9]Match any of the above8[^aeiou]Match anything other than a lowercase vowel9[^0-9]Match anything other than a digitSpecial Character ClassesSr.No.Example ... Read More

All the CGI programs have access to the following environment variables. These variables play an important role while writing any CGI program.Sr.No.Variable Name & Description1CONTENT_TYPEThe data type of the content. Used when the client is sending attached content to the server. For example, file upload.2CONTENT_LENGTHThe length of the query information. ... Read More

Sr.No.Example & Description1R(?#comment)Matches "R". All the rest is a comment2R(?i)ubyCase-insensitive while matching "uby"3R(?i:uby)Same as above4rub(?:y|le))Group only without creating \1 backreference