Some really simple cgi examples. cgi3 is a MiniWiki.

Demo/cgi/cgi0.sh

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+#! /bin/sh
+
+# If you can't get this to work, your web server isn't set up right
+
+echo Content-type: text/plain
+echo
+echo Hello world
+echo This is cgi0.sh

Demo/cgi/cgi1.py

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+#!/usr/local/bin/python
+
+"""CGI test 1 - check server setup."""
+
+# Until you get this to work, your web server isn't set up right or
+# your Python isn't set up right.
+
+# If cgi0.sh works but cgi1.py, check the #! line and the file
+# permissions.  The docs for the cgi.py module have debugging tips.
+
+print "Content-type: text/html"
+print
+print "<h1>Hello world</h1>"
+print "<p>This is cgi1.py"

Demo/cgi/cgi2.py

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+#!/usr/local/bin/python
+
+"""CGI test 2 - basic use of cgi module."""
+
+import cgitb; cgitb.enable()
+
+import cgi
+
+def main():
+    form = cgi.FieldStorage()
+    print "Content-type: text/html"
+    print
+    if not form:
+        print "<h1>No Form Keys</h1>"
+    else:
+        print "<h1>Form Keys</h1>"
+        for key in form.keys():
+            value = form[key].value
+            print "<p>", cgi.escape(key), ":", cgi.escape(value)
+
+if __name__ == "__main__":
+    main()

Demo/cgi/cgi3.py

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+#!/usr/local/bin/python
+
+"""CGI test 3 (persistent data)."""
+
+import cgitb; cgitb.enable()
+
+import os, re, cgi, sys
+escape = cgi.escape
+
+def main():
+    form = cgi.FieldStorage()
+    print "Content-type: text/html"
+    print
+    cmd = form.getvalue("cmd") or "view"
+    page = form.getvalue("page") or "FrontPage"
+    wiki = WikiPage(page)
+    wiki.load()
+    method = getattr(wiki, 'cmd_' + cmd, None) or wiki.cmd_view
+    method(form)
+
+class WikiPage:
+
+    homedir = os.path.dirname(sys.argv[0])
+    scripturl = os.path.basename(sys.argv[0])
+
+    def __init__(self, name):
+        self.name = name
+        self.load()
+
+    def cmd_view(self, form):
+        print "<h1>", escape(self.splitwikiword(self.name)), "</h1>"
+        print "<p>"
+        for line in self.data.splitlines():
+            line = line.rstrip()
+            if not line:
+                print "<p>"
+                continue
+            words = re.split('(\W+)', line)
+            for i in range(len(words)):
+                word = words[i]
+                if self.iswikiword(word):
+                    if os.path.isfile(self.mkfile(word)):
+                        word = self.mklink("view", word, word)
+                    else:
+                        word = self.mklink("new", word, word + "*")
+                else:
+                    word = escape(word)
+                words[i] = word
+            print "".join(words)
+        print "<hr>"
+        print "<p>", self.mklink("edit", self.name, "Edit this page") + ","
+        print self.mklink("view", "FrontPage", "go to front page") + "."
+
+    def cmd_edit(self, form, label="Change"):
+        print "<h1>", label, self.name, "</h1>"
+        print '<form method="POST" action="%s">' % self.scripturl
+        s = '<textarea cols="70" rows="20" name="text">%s</textarea>'
+        print s % self.data
+        print '<input type="hidden" name="cmd" value="create">'
+        print '<input type="hidden" name="page" value="%s">' % self.name
+        print '<br>'
+        print '<input type="submit" value="%s Page">' % label
+        print "</form>"
+
+    def cmd_create(self, form):
+        self.data = form.getvalue("text", "").strip()
+        self.store()
+        self.cmd_view(form)
+
+    def cmd_new(self, form):
+        self.cmd_edit(form, label="Create Page")
+
+    def iswikiword(self, word):
+        return re.match("[A-Z][a-z]+([A-Z][a-z]*)+", word)
+
+    def splitwikiword(self, word):
+        chars = []
+        for c in word:
+            if chars and c.isupper():
+                chars.append(' ')
+            chars.append(c)
+        return "".join(chars)
+
+    def mkfile(self, name=None):
+        if name is None:
+            name = self.name
+        return os.path.join(self.homedir, name)
+
+    def mklink(self, cmd, page, text):
+        link = self.scripturl + "?cmd=" + cmd + "&page=" + page
+        return '<a href="%s">%s</a>' % (link, text)
+
+    def load(self):
+        try:
+            f = open(self.mkfile())
+            data = f.read().strip()
+            f.close()
+        except IOError:
+            data = ""
+        self.data = data
+
+    def store(self):
+        data = self.data
+        try:
+            f = open(self.mkfile(), "w")
+            f.write(data)
+            f.close()
+            return ""
+        except IOError, err:
+            return "IOError: %s" % str(err)
+
+if __name__ == "__main__":
+    main()