python/serve-ssi

   1 #!/usr/bin/python
   2
   3 # This program is quite incomplete. I might complete it with more
   4 # features as I need them. It will probably never be entirely
   5 # compliant with Apache's version due to architectural differences.
   6
   7 import sys, os, time
   8
   9 def htmlquote(text):
  10     ret = ""
  11     for c in text:
  12         if c == '&':
  13             ret += "&amp;"
  14         elif c == '<':
  15             ret += "&lt;"
  16         elif c == '>':
  17             ret += "&gt;"
  18         elif c == '"':
  19             ret += "&quot;"
  20         else:
  21             ret += c
  22     return ret
  23
  24 def simpleerror(out, code, title, msg):
  25     html = """<?xml version="1.0" encoding="US-ASCII"?>
  26 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
  27 <html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">
  28 <head>
  29 <title>%s</title>
  30 </head>
  31 <body>
  32 <h1>%s</h1>
  33 <p>%s</p>
  34 </body>
  35 </html>
  36 """ % (title, title, htmlquote(msg))
  37     out.write("HTTP/1.1 %d %s\n" % (code, title))
  38     out.write("Content-Type: text/html\n")
  39     out.write("Content-Length: %d\n" % len(html))
  40     out.write("\n")
  41     out.write(html)
  42
  43 ssivars = {}
  44
  45 def parsecmd(line, p):
  46     try:
  47         while line[p].isspace(): p += 1
  48         cmd = ""
  49         while not line[p].isspace():
  50             cmd += line[p]
  51             p += 1
  52         pars = {}
  53         while True:
  54             while line[p].isspace(): p += 1
  55             if line[p:p + 3] == "-->":
  56                 return cmd, pars, p + 3
  57             key = ""
  58             while line[p].isalnum():
  59                 key += line[p]
  60                 p += 1
  61             if key == "":
  62                 return None, {}, p
  63             while line[p].isspace(): p += 1
  64             if line[p] != '=':
  65                 continue
  66             p += 1
  67             while line[p].isspace(): p += 1
  68             q = line[p]
  69             if q != '"' and q != "'" and q != '`':
  70                 continue
  71             val = ""
  72             p += 1
  73             while line[p] != q:
  74                 val += line[p]
  75                 p += 1
  76             p += 1
  77             pars[key] = val
  78     except IndexError:
  79         return None, {}, len(line)
  80
  81 class ssifile(object):
  82     def __init__(self, s, url, path):
  83         self.s = s
  84         self.url = url
  85         self.path = path
  86
  87     def close(self):
  88         self.s.close();
  89
  90     def initvars(self, vars):
  91         now = time.time()
  92         vars["DOCUMENT_NAME"] = os.path.basename(self.path)
  93         vars["DATE_GMT"] = time.asctime(time.gmtime(now))
  94         vars["DATE_LOCAL"] = time.asctime(time.localtime(now))
  95         vars["LAST_MODIFIED"] = time.asctime(time.localtime(os.stat(self.path).st_mtime))
  96
  97     def includefile(self, path):
  98         path = os.path.join(os.path.dirname(self.path), path)
  99         try:
 100             f = ssifile(open(path), url, path)
 101         except Exception:
 102             sys.stderr.write("serve-ssi: included file not found: %s\n" % path)
 103             return
 104         try:
 105             f.process()
 106         finally:
 107             f.close
 108
 109     def docmd(self, cmd, pars):
 110         if cmd == "include":
 111             if "file" in pars:
 112                 self.includefile(pars["file"])
 113             elif "virtual" in pars:
 114                 # XXX: For now, just include the file as-is. Change
 115                 # when necessary.
 116                 self.includefile(pars["virtual"])
 117         elif cmd == "echo":
 118             enc = htmlquote
 119             if "encoding" in pars:
 120                 if pars["encoding"] == "entity":
 121                     enc = htmlquote
 122             if "var" in pars:
 123                 if pars["var"] in ssivars:
 124                     sys.stdout.write(enc(ssivars[pars["var"]]))
 125         else:
 126             sys.stderr.write("serve-ssi: unknown SSI command: %s\n" % cmd)
 127
 128     def process(self):
 129         for line in self.s:
 130             p = 0
 131             while True:
 132                 p2 = line.find("<!--#", p)
 133                 if p2 < 0:
 134                     sys.stdout.write(line[p:])
 135                     break
 136                 sys.stdout.write(line[p:p2])
 137                 cmd, pars, p = parsecmd(line, p2 + 5)
 138                 if cmd is not None:
 139                     self.docmd(cmd, pars)
 140
 141 if len(sys.argv) < 4:
 142     sys.stderr.write("usage: serve-ssi METHOD URL REST\n")
 143     sys.exit(1)
 144 method, url, rest = sys.argv[1:]
 145 path = os.getenv("REQ_X_ASH_FILE")
 146 if path is None:
 147     sys.stderr.write("serve-ssi: must be called with the X-Ash-File header\n")
 148     sys.exit(1)
 149 if rest != "":
 150     simpleerror(sys.stdout, 404, "Not Found", "The resource specified by the URL does not exist.")
 151     sys.exit(0)
 152
 153 try:
 154     try:
 155         f = ssifile(open(path), url, path)
 156     except Exception:
 157         simpleerror(sys.stdout, 500, "Server Error", "The server could not access its data.")
 158         sys.exit(1)
 159     try:
 160         sys.stdout.write("HTTP/1.1 200 OK\n")
 161         sys.stdout.write("Content-Type: text/html\n")
 162         sys.stdout.write("\n")
 163         f.initvars(ssivars)
 164         f.process()
 165     finally:
 166         f.close()
 167 except IOError:
 168     # This is for catching EPIPE, when the client has closed the
 169     # connection. This shouldn't *really* be necessary since the
 170     # process should terminate with SIGPIPE, but apparently Python
 171     # ignores that.
 172     sys.exit(1)