12
Redirection
CGI/Perl
Programming
By Diane Zak
1
12
Objectives
• In this chapter, you will:
• Include the Location header in a
script
• Include the Refresh header in a
script
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12
Introduction
• Documents often move on the
Web from one location to another
– Link to new URL so user must
click to go to new location
– Automatically forward the browser
to a new address
• Immediately
• After a period of time (seconds)
– META tag – HTML
– Location Header – script
– Refresh Header - script
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Redirecting a browser
• Location header:
– Immediately redirects the browser
– Syntax:
• print “Location: url\n\n”;
– Example:
print “Location:
http://www.rsp.com/public_html/chap12/error.html\n\n”;
• The 1st newline character identifies the end of the
Location header
• The 2nd newline character inserts a blank line
below the header to signal end of header section
• Location header used instead of Content-type
header
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12
Redirecting a Browser
• Refresh header:
– Waits a specified number of seconds before
redirection
– Syntax:
• print “Refresh: seconds; URL=url\n”;
– Example:
print “Refresh: 3;
URL=“http://www.rsp.com/public_html/chap12/error.html\n”;
print “Content-type: text/html\n\n”;
• Contains one newline character because it is used
with the Content-type header
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Using a Refresh Header
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6
12
Using a Refresh Header
• Uses Refresh header to redirect
the page in 3 seconds
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12
Using a Location Header
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12
Using a Location Header
If no Name was
typed into the
cara1.html
page
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Summary
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• You can use the Location header or the
Refresh header in a CGI script to redirect
the user’s browser to another location.
• The Location header redirects the browser
immediately.
– Syntax: print “Location: url\n\n”;
• The Refresh header waits for a specified
number of seconds until redirection.
– Syntax: print “Refresh: seconds; URL=url\n”;
– Is used together with the Content-type header
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