Example 9
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#!/usr/local/bin/perl
# The above must appear as the first line of the script if Perl is to be invoked,
# and must appear as written, except for the path to the Perl executable.
# Standard subroutine to parse the string sent from the Web client. This is
# freely available (see below) and will process strings sent by both the POST
# and the GET methods. Typically you would call this as a function from a
# separate library as we shall see in the next example.
#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
# Perl Routines to Manipulate CGI input
# S.E.Brenner@bioc.cam.ac.uk
# $Header: /cys/people/seb1005/http/cgi-bin/RCS/cgi-lib.pl,v 1.6 1994/07/13 15:00:50 seb1005 Exp $
#
# Copyright 1994 Steven E. Brenner
# Unpublished work.
# Permission granted to use and modify this library so long as the
# copyright above is maintained, modifications are documented, and
# credit is given for any use of the library.
#
# Thanks are due to many people for reporting bugs and suggestions
# especially Meng Weng Wong, Maki Watanabe, Bo Frese Rasmussen,
# Andrew Dalke, Mark-Jason Dominus.
# see http://www.seas.upenn.edu/~mengwong/forms/ or
# http://www.bio.cam.ac.uk/web/ for more information
# The following is a minimal example for using ReadParse and is
# included as a comment.
# Example of minimalist http form and script
# (http://www.bio.cam.ac.uk/web/minimal.cgi):
# if (&MethGet) {
# print &PrintHeader,
# '<form method=POST><input type="submit">Data: <input name="myfield">';
# } else {
# &ReadParse(*input);
# print &PrintHeader, &PrintVariables(%input);
# }
# ReadParse
# Reads in GET or POST data, converts it to unescaped text, and puts
# one key=value in each member of the list "@in"
# Also creates key/value pairs in %in, using '\0' to separate multiple
# selections
# If a variable-glob parameter (e.g., *cgi_input) is passed to ReadParse,
# information is stored there, rather than in $in, @in, and %in.
sub ReadParse {
local (*in) = @_ if @_;
local ($i, $loc, $key, $val);
# Read in text
# The text is equated to the variable "in"
# For the GET method in comes from the environment variable
# QUERY_STRING
# For the POST method it is read from standatd input. Note that since
# new line characters are escaped there is no telling where this variable
# ends. The CONTENT_LENGTH environment variable specifies
# exactly how many bytes are to be read into in from STDIN.
if ($ENV{'REQUEST_METHOD'} eq "GET") {
$in = $ENV{'QUERY_STRING'};
} elsif ($ENV{'REQUEST_METHOD'} eq "POST") {
read(STDIN,$in,$ENV{'CONTENT_LENGTH'});
}
@in = split(/&/,$in);
foreach $i (0 .. $#in) {
# Convert plus's to spaces
$in[$i] =~ s/\+/ /g;
# Split into key and value.
($key, $val) = split(/=/,$in[$i],2); # splits on the first =.
# Convert %XX from hex numbers to alphanumeric
$key =~ s/%(..)/pack("c",hex($1))/eg;
$val =~ s/%(..)/pack("c",hex($1))/eg;
# Associate key and value
# This gives us an associative array (a neat feature in Perl, C and some other
# languages, which has entries of the form, in this example, of:
# in(name) = phil
# in(email) = bourne@sdsc.edu
$in{$key} .= "\0" if (defined($in{$key})); # \0 is the multiple separator
$in{$key} .= $val;
}
return 1;
}
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
# Now our specific application code which is simply going to write out
# the contents of the associative array in the desired format.
&ReadParse();
# Open the file comments.txt which resides in the same directory as the CGI script
# and which already contains comments and append to it.
open (COMMENTS, ">>comments.txt") || die "Cannot open comment.txt: $!\n";
# Enter the date and time taken from the UNIX date command.
$date = `/bin/date +%D`;
print COMMENTS "##########################################################\n\n";
print COMMENTS "$date\n";
if ($in{'name'} ne '') {
print COMMENTS "Posted by: $in{'name'}\n";
}
if ($in{'email'} ne '') {
print COMMENTS "Email: $in{'email'}\n";
}
if ($in{'phone'} ne '') {
print COMMENTS "Phone number: $in{'phone'}\n";
}
$in{'comments'} =~ s/\//g;
print COMMENTS "\nComments:\n\n$in{'comments'}\n\n";
# That does it for the output file now we worry about what to pass back to
# the client Web browser that indicates that the comments have been registered.
# To do this we simply write to standard output. We first tell the browser
# that we are passing back HTML and it should be interpreted accordingly.
print "Content-type: text/html\n\n";
print "<TITLE>Posting Successful</TITLE>";
print "<BODY BACKGROUND=\"bg.gif\">";
print "<CENTER><P>";
print "<B>Your comments were succesfully logged.</B>";
print "<P><img ALIGN=middle SRC=\"images/hrblue.gif\"><p>";
print "<a href = \"./Databases.html\"> Databases</a> |";
print "<a href = \"./Software.html\"> Software</a> |";
print "<a href = \"./Research.html\"> Research</a> |";
print "<a href = \"./People.html\"> People</a> |";
print "<a href = \"./Pubs.html\"> Publications</a> |";
print "<a href = \"./Grants.html\"> Grants</a> |";
print "<a href = \"./Comments.html\"> Comments</a> |";
print "<a href = \"./Help.html\"> Help</a> <BR>";
print "<a href = \"./Search.html\"> Text Search</a> |";
print "<a href = \"http://www.sdsc.edu/\"> SDSC Home Page</a> <P>";
print "<img ALIGN=middle SRC=\"images/hrblue.gif\">";
print "</CENTER>";
The comment that appears in the file comments.txt resulting from the execution of this script is
##########################################################
05/24/96
Posted by: phil
Email: bourne@sdsc.edu
Phone number: (xxx) yyy-zzzz
Comments:
My Comments
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