Sending data in cgi
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The document discusses sending form data to a Perl script using CGI and parsing the data in the script. It describes creating an HTML form that allows a user to enter a comment, and submitting it to a Perl script. The script then parses the submitted form data and prints out the comment. The document also covers using GET vs POST methods, declaring variables, and formatting output with printf.
![Including special characters This project uses a dollar sign, which can’t be typed in directly (why not?) Characters that are given special meaning within a regular expression Backslash if you want to use literally :. * ? + [ ] ( ) { } ^ $ | \ Any other characters automatically assume their literal meanings.](https://image.slidesharecdn.com/sendingdataincgi-100823133801-phpapp01/85/Sending-data-in-cgi-8-320.jpg)
Sending data in cgi
- 1. Sending Data Using an Online Form CISIWEB 430A
- 2. Objectives In this unit, you will Plan and create a CGI script that processes form data Learn how to prevent Perl from creating undeclared variables in a script Declare (create) scalar variables in a script Use assignment statements to assign values to existing variables Send form data to a script using GET and POST Improve the appearance of numbers displayed on a Web page
- 3. <html> <head> <title>Chapter 3 - Parsing Data</title> </head> <body bgcolor="#FFFFFF"> <form action="http://myServer/parse2.cgi" METHOD=POST> Comment <input type="text" name="myComment"> <p> <input TYPE = "submit" value = "Submit"> <input TYPE = "reset" VALUE = "Start Over"> </p> </form> </body> </html> #!/usr/bin/perl use CGI qw(:standard); print "Content-type: text/html\n\n"; print "<HTML><HEAD><TITLE>Chapter 3"; print " - Output</TITLE></HEAD><BODY>\n"; print param('myComment'); print "</BODY></HTML>";
- 4. Planning the script Plan the HTML page Plan the logic for the script Plan the information the script will output
- 5. Accessing Form Data In an HTML form, the keys are the names of the form elements, and the values are the information (usually) entered by a user. When the user presses the “Submit” button, the data are automatically transmitted to the script. Once the data are sent, our script needs to parse the data so that we can use it. If we use the CGI.pm module, parsing the data from a form is identical to parsing the data from a hyperlink.
- 6. Creating the Form Use HTML to create the form FORM tag contains instructions Action = location of .cgi Method = Get or Post Submit – calls the action to happen Controls – include a name attribute
- 7. Get vs. Post GET appends the form data to the end of the URL specified in the action property and is similar to sending the data through a hyperlink POST sends the data as a separate data stream, allowing the Web server to receive the data through “STANDARD INPUT”
- 8. Including special characters This project uses a dollar sign, which can’t be typed in directly (why not?) Characters that are given special meaning within a regular expression Backslash if you want to use literally :. * ? + [ ] ( ) { } ^ $ | \ Any other characters automatically assume their literal meanings.
- 9. Using printf Printf function is used for displaying data on a Web page Allows you to format the information Allows you to specify the number of decimal places Allows you to display a + or – before the number Syntax: printf formatstring, list; List is a comma separated list of items Formatstring contains text and one or more format fields
- 10. Parts of a format field % - required, at the beginning of a format field Modifier – optional (+ or – to denote a positive or negative number) Minimum field width – option, sets a min number of characters to display Precision – optoin, expressed as a period followed by a number, the number of digits to the right of the decimal Format type – required – d (decimal) or f (floating point)