Tomcat example source code file (CGIServlet.java)

This example Tomcat source code file (CGIServlet.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Tomcat tags/keywords

bufferedreader, cgienvironment, enumeration, file, file, hashtable, hashtable, http, inputstream, io, ioexception, ioexception, request, response, servlet, string, string, stringbuffer, stringtokenizer, util

The Tomcat CGIServlet.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


package org.apache.catalina.servlets;

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.ArrayList;
import java.util.Date;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Locale;
import java.util.StringTokenizer;
import java.util.Vector;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.UnavailableException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.catalina.Globals;
import org.apache.catalina.util.IOTools;


/**
 *  CGI-invoking servlet for web applications, used to execute scripts which
 *  comply to the Common Gateway Interface (CGI) specification and are named
 *  in the path-info used to invoke this servlet.
 *
 * <p>
 * <i>Note: This code compiles and even works for simple CGI cases.
 *          Exhaustive testing has not been done.  Please consider it beta
 *          quality.  Feedback is appreciated to the author (see below).</i>
 * </p>
 * <p>
 *
 * <b>Example:

 * If an instance of this servlet was mapped (using
 *       <code><web-app>/WEB-INF/web.xml) to:
 * </p>
 * <p>
 * <code>
 * <web-app>/cgi-bin/*
 * </code>
 * </p>
 * <p>
 * then the following request:
 * </p>
 * <p>
 * <code>
 * http://localhost:8080/<web-app>/cgi-bin/dir1/script/pathinfo1
 * </code>
 * </p>
 * <p>
 * would result in the execution of the script
 * </p>
 * <p>
 * <code>
 * <web-app-root>/WEB-INF/cgi/dir1/script
 * </code>
 * </p>
 * <p>
 * with the script's <code>PATH_INFO set to /pathinfo1.
 * </p>
 * <p>
 * Recommendation:  House all your CGI scripts under
 * <code><webapp>/WEB-INF/cgi.  This will ensure that you do not
 * accidentally expose your cgi scripts' code to the outside world and that
 * your cgis will be cleanly ensconced underneath the WEB-INF (i.e.,
 * non-content) area.
 * </p>
 * <p>
 * The default CGI location is mentioned above.  You have the flexibility to
 * put CGIs wherever you want, however:
 * </p>
 * <p>
 *   The CGI search path will start at
 *   webAppRootDir + File.separator + cgiPathPrefix
 *   (or webAppRootDir alone if cgiPathPrefix is
 *   null).
 * </p>
 * <p>
 *   cgiPathPrefix is defined by setting
 *   this servlet's cgiPathPrefix init parameter
 * </p>
 *
 * <p>
 *
 * <B>CGI Specification:
 derived from
 * <a href="http://cgi-spec.golux.com">http://cgi-spec.golux.com.
 * A work-in-progress & expired Internet Draft.  Note no actual RFC describing
 * the CGI specification exists.  Where the behavior of this servlet differs
 * from the specification cited above, it is either documented here, a bug,
 * or an instance where the specification cited differs from Best
 * Community Practice (BCP).
 * Such instances should be well-documented here.  Please email the
 * <a href="mailto:tomcat-dev@jakarta.apache.org">Jakarta Tomcat group [tomcat-dev@jakarta.apache.org]
 * with amendments.
 *
 * </p>
 * <p>
 *
 * <b>Canonical metavariables:

 * The CGI specification defines the following canonical metavariables:
 * <br>
 * [excerpt from CGI specification]
 * <PRE>
 *  AUTH_TYPE
 *  CONTENT_LENGTH
 *  CONTENT_TYPE
 *  GATEWAY_INTERFACE
 *  PATH_INFO
 *  PATH_TRANSLATED
 *  QUERY_STRING
 *  REMOTE_ADDR
 *  REMOTE_HOST
 *  REMOTE_IDENT
 *  REMOTE_USER
 *  REQUEST_METHOD
 *  SCRIPT_NAME
 *  SERVER_NAME
 *  SERVER_PORT
 *  SERVER_PROTOCOL
 *  SERVER_SOFTWARE
 * </PRE>
 * <p>
 * Metavariables with names beginning with the protocol name (<EM>e.g.,
 * "HTTP_ACCEPT") are also canonical in their description of request header
 * fields.  The number and meaning of these fields may change independently
 * of this specification.  (See also section 6.1.5 [of the CGI specification].)
 * </p>
 * [end excerpt]
 *
 * </p>
 * <h2> Implementation notes
 * <p>
 *
 * <b>standard input handling: If your script accepts standard input,
 * then the client must start sending input within a certain timeout period,
 * otherwise the servlet will assume no input is coming and carry on running
 * the script.  The script's the standard input will be closed and handling of
 * any further input from the client is undefined.  Most likely it will be
 * ignored.  If this behavior becomes undesirable, then this servlet needs
 * to be enhanced to handle threading of the spawned process' stdin, stdout,
 * and stderr (which should not be too hard).
 * <br>
 * If you find your cgi scripts are timing out receiving input, you can set
 * the init parameter <code> of your webapps' cgi-handling servlet
 * to be
 * </p>
 * <p>
 *
 * <b>Metavariable Values: According to the CGI specificion,
 * implementations may choose to represent both null or missing values in an
 * implementation-specific manner, but must define that manner.  This
 * implementation chooses to always define all required metavariables, but
 * set the value to "" for all metavariables whose value is either null or
 * undefined.  PATH_TRANSLATED is the sole exception to this rule, as per the
 * CGI Specification.
 *
 * </p>
 * <p>
 *
 * <b>NPH --  Non-parsed-header implementation:  This implementation does
 * not support the CGI NPH concept, whereby server ensures that the data
 * supplied to the script are preceisely as supplied by the client and
 * unaltered by the server.
 * </p>
 * <p>
 * The function of a servlet container (including Tomcat) is specifically
 * designed to parse and possible alter CGI-specific variables, and as
 * such makes NPH functionality difficult to support.
 * </p>
 * <p>
 * The CGI specification states that compliant servers MAY support NPH output.
 * It does not state servers MUST support NPH output to be unconditionally
 * compliant.  Thus, this implementation maintains unconditional compliance
 * with the specification though NPH support is not present.
 * </p>
 * <p>
 *
 * The CGI specification is located at
 * <a href="http://cgi-spec.golux.com">http://cgi-spec.golux.com.
 *
 * </p>
 * <p>
 * <h3>TODO:
 * <ul>
 * <li> Support for setting headers (for example, Location headers don't work)
 * <li> Support for collapsing multiple header lines (per RFC 2616)
 * <li> Ensure handling of POST method does not interfere with 2.3 Filters
 * <li> Refactor some debug code out of core
 * <li> Ensure header handling preserves encoding
 * <li> Possibly rewrite CGIRunner.run()?
 * <li> Possibly refactor CGIRunner and CGIEnvironment as non-inner classes?
 * <li> Document handling of cgi stdin when there is no stdin
 * <li> Revisit IOException handling in CGIRunner.run()
 * <li> Better documentation
 * <li> Confirm use of ServletInputStream.available() in CGIRunner.run() is
 *      not needed
 * <li> Make checking for "." and ".." in servlet & cgi PATH_INFO less
 *      draconian
 * <li> [add more to this TODO list]
 * </ul>
 * </p>
 *
 * @author Martin T Dengler [root@martindengler.com]
 * @author Amy Roh
 * @version $Revision: 595801 $, $Date: 2007-11-16 21:07:07 +0100 (ven., 16 nov. 2007) $
 * @since Tomcat 4.0
 *
 */


public final class CGIServlet extends HttpServlet {

    /* some vars below copied from Craig R. McClanahan's InvokerServlet */

    /** the debugging detail level for this servlet. */
    private int debug = 0;

    /**
     *  The CGI search path will start at
     *    webAppRootDir + File.separator + cgiPathPrefix
     *    (or webAppRootDir alone if cgiPathPrefix is
     *    null)
     */
    private String cgiPathPrefix = null;

    /** the executable to use with the script */
    private String cgiExecutable = "perl";
    
    /** the encoding to use for parameters */
    private String parameterEncoding = System.getProperty("file.encoding",
                                                          "UTF-8");

    /** object used to ensure multiple threads don't try to expand same file */
    static Object expandFileLock = new Object();

    /** the shell environment variables to be passed to the CGI script */
    static Hashtable<String,String> shellEnv = new Hashtable();

    /**
     * Sets instance variables.
     * <P>
     * Modified from Craig R. McClanahan's InvokerServlet
     * </P>
     *
     * @param config                    a <code>ServletConfig object
     *                                  containing the servlet's
     *                                  configuration and initialization
     *                                  parameters
     *
     * @exception ServletException      if an exception has occurred that
     *                                  interferes with the servlet's normal
     *                                  operation
     */
    public void init(ServletConfig config) throws ServletException {

        super.init(config);

        // Verify that we were not accessed using the invoker servlet
        String servletName = getServletConfig().getServletName();
        if (servletName == null)
            servletName = "";
        if (servletName.startsWith("org.apache.catalina.INVOKER."))
            throw new UnavailableException
                ("Cannot invoke CGIServlet through the invoker");
        
        // Set our properties from the initialization parameters
        if (getServletConfig().getInitParameter("debug") != null)
            debug = Integer.parseInt(getServletConfig().getInitParameter("debug"));
        cgiPathPrefix = getServletConfig().getInitParameter("cgiPathPrefix");
        boolean passShellEnvironment = 
            Boolean.valueOf(getServletConfig().getInitParameter("passShellEnvironment")).booleanValue();

        if (passShellEnvironment) {
            try {
                shellEnv.putAll(getShellEnvironment());
            } catch (IOException ioe) {
                ServletException e = new ServletException(
                        "Unable to read shell environment variables", ioe);
                throw e;
            }
        }

        if (getServletConfig().getInitParameter("executable") != null) {
            cgiExecutable = getServletConfig().getInitParameter("executable");
        }

        if (getServletConfig().getInitParameter("parameterEncoding") != null) {
            parameterEncoding = getServletConfig().getInitParameter("parameterEncoding");
        }

    }



    /**
     * Prints out important Servlet API and container information
     *
     * <p>
     * Copied from SnoopAllServlet by Craig R. McClanahan
     * </p>
     *
     * @param  out    ServletOutputStream as target of the information
     * @param  req    HttpServletRequest object used as source of information
     * @param  res    HttpServletResponse object currently not used but could
     *                provide future information
     *
     * @exception  IOException  if a write operation exception occurs
     *
     */
    protected void printServletEnvironment(ServletOutputStream out,
        HttpServletRequest req, HttpServletResponse res) throws IOException {

        // Document the properties from ServletRequest
        out.println("<h1>ServletRequest Properties");
        out.println("<ul>");
        Enumeration attrs = req.getAttributeNames();
        while (attrs.hasMoreElements()) {
            String attr = (String) attrs.nextElement();
            out.println("<li>attribute " + attr + " = " +
                           req.getAttribute(attr));
        }
        out.println("<li>characterEncoding = " +
                       req.getCharacterEncoding());
        out.println("<li>contentLength = " +
                       req.getContentLength());
        out.println("<li>contentType = " +
                       req.getContentType());
        Enumeration locales = req.getLocales();
        while (locales.hasMoreElements()) {
            Locale locale = (Locale) locales.nextElement();
            out.println("<li>locale = " + locale);
        }
        Enumeration params = req.getParameterNames();
        while (params.hasMoreElements()) {
            String param = (String) params.nextElement();
            String values[] = req.getParameterValues(param);
            for (int i = 0; i < values.length; i++)
                out.println("<li>parameter " + param + " = " +
                               values[i]);
        }
        out.println("<li>protocol = " + req.getProtocol());
        out.println("<li>remoteAddr = " + req.getRemoteAddr());
        out.println("<li>remoteHost = " + req.getRemoteHost());
        out.println("<li>scheme = " + req.getScheme());
        out.println("<li>secure = " + req.isSecure());
        out.println("<li>serverName = " + req.getServerName());
        out.println("<li>serverPort = " + req.getServerPort());
        out.println("</ul>");
        out.println("<hr>");

        // Document the properties from HttpServletRequest
        out.println("<h1>HttpServletRequest Properties");
        out.println("<ul>");
        out.println("<li>authType = " + req.getAuthType());
        out.println("<li>contextPath = " +
                       req.getContextPath());
        Cookie cookies[] = req.getCookies();
        if (cookies!=null) {
            for (int i = 0; i < cookies.length; i++)
                out.println("<li>cookie " + cookies[i].getName() +" = " +cookies[i].getValue());
        }
        Enumeration headers = req.getHeaderNames();
        while (headers.hasMoreElements()) {
            String header = (String) headers.nextElement();
            out.println("<li>header " + header + " = " +
                           req.getHeader(header));
        }
        out.println("<li>method = " + req.getMethod());
        out.println("<li>pathInfo = "
                    + req.getPathInfo());
        out.println("<li>pathTranslated = " +
                       req.getPathTranslated());
        out.println("<li>queryString = " +
                       req.getQueryString());
        out.println("<li>remoteUser = " +
                       req.getRemoteUser());
        out.println("<li>requestedSessionId = " +
                       req.getRequestedSessionId());
        out.println("<li>requestedSessionIdFromCookie = " +
                       req.isRequestedSessionIdFromCookie());
        out.println("<li>requestedSessionIdFromURL = " +
                       req.isRequestedSessionIdFromURL());
        out.println("<li>requestedSessionIdValid = " +
                       req.isRequestedSessionIdValid());
        out.println("<li>requestURI = " +
                       req.getRequestURI());
        out.println("<li>servletPath = " +
                       req.getServletPath());
        out.println("<li>userPrincipal = " +
                       req.getUserPrincipal());
        out.println("</ul>");
        out.println("<hr>");

        // Document the servlet request attributes
        out.println("<h1>ServletRequest Attributes");
        out.println("<ul>");
        attrs = req.getAttributeNames();
        while (attrs.hasMoreElements()) {
            String attr = (String) attrs.nextElement();
            out.println("<li>" + attr + " = " +
                           req.getAttribute(attr));
        }
        out.println("</ul>");
        out.println("<hr>");

        // Process the current session (if there is one)
        HttpSession session = req.getSession(false);
        if (session != null) {

            // Document the session properties
            out.println("<h1>HttpSession Properties");
            out.println("<ul>");
            out.println("<li>id = " +
                           session.getId());
            out.println("<li>creationTime = " +
                           new Date(session.getCreationTime()));
            out.println("<li>lastAccessedTime = " +
                           new Date(session.getLastAccessedTime()));
            out.println("<li>maxInactiveInterval = " +
                           session.getMaxInactiveInterval());
            out.println("</ul>");
            out.println("<hr>");

            // Document the session attributes
            out.println("<h1>HttpSession Attributes");
            out.println("<ul>");
            attrs = session.getAttributeNames();
            while (attrs.hasMoreElements()) {
                String attr = (String) attrs.nextElement();
                out.println("<li>" + attr + " = " +
                               session.getAttribute(attr));
            }
            out.println("</ul>");
            out.println("<hr>");

        }

        // Document the servlet configuration properties
        out.println("<h1>ServletConfig Properties");
        out.println("<ul>");
        out.println("<li>servletName = " +
                       getServletConfig().getServletName());
        out.println("</ul>");
        out.println("<hr>");

        // Document the servlet configuration initialization parameters
        out.println("<h1>ServletConfig Initialization Parameters");
        out.println("<ul>");
        params = getServletConfig().getInitParameterNames();
        while (params.hasMoreElements()) {
            String param = (String) params.nextElement();
            String value = getServletConfig().getInitParameter(param);
            out.println("<li>" + param + " = " + value);
        }
        out.println("</ul>");
        out.println("<hr>");

        // Document the servlet context properties
        out.println("<h1>ServletContext Properties");
        out.println("<ul>");
        out.println("<li>majorVersion = " +
                       getServletContext().getMajorVersion());
        out.println("<li>minorVersion = " +
                       getServletContext().getMinorVersion());
        out.println("<li>realPath('/') = " +
                       getServletContext().getRealPath("/"));
        out.println("<li>serverInfo = " +
                       getServletContext().getServerInfo());
        out.println("</ul>");
        out.println("<hr>");

        // Document the servlet context initialization parameters
        out.println("<h1>ServletContext Initialization Parameters");
        out.println("<ul>");
        params = getServletContext().getInitParameterNames();
        while (params.hasMoreElements()) {
            String param = (String) params.nextElement();
            String value = getServletContext().getInitParameter(param);
            out.println("<li>" + param + " = " + value);
        }
        out.println("</ul>");
        out.println("<hr>");

        // Document the servlet context attributes
        out.println("<h1>ServletContext Attributes");
        out.println("<ul>");
        attrs = getServletContext().getAttributeNames();
        while (attrs.hasMoreElements()) {
            String attr = (String) attrs.nextElement();
            out.println("<li>" + attr + " = " +
                           getServletContext().getAttribute(attr));
        }
        out.println("</ul>");
        out.println("<hr>");



    }



    /**
     * Provides CGI Gateway service -- delegates to <code>doGet
     *
     * @param  req   HttpServletRequest passed in by servlet container
     * @param  res   HttpServletResponse passed in by servlet container
     *
     * @exception  ServletException  if a servlet-specific exception occurs
     * @exception  IOException  if a read/write exception occurs
     *
     * @see javax.servlet.http.HttpServlet
     *
     */
    protected void doPost(HttpServletRequest req, HttpServletResponse res)
        throws IOException, ServletException {
        doGet(req, res);
    }



    /**
     * Provides CGI Gateway service
     *
     * @param  req   HttpServletRequest passed in by servlet container
     * @param  res   HttpServletResponse passed in by servlet container
     *
     * @exception  ServletException  if a servlet-specific exception occurs
     * @exception  IOException  if a read/write exception occurs
     *
     * @see javax.servlet.http.HttpServlet
     *
     */
    protected void doGet(HttpServletRequest req, HttpServletResponse res)
        throws ServletException, IOException {

        // Verify that we were not accessed using the invoker servlet
        if (req.getAttribute(Globals.INVOKED_ATTR) != null)
            throw new UnavailableException
                ("Cannot invoke CGIServlet through the invoker");

        CGIEnvironment cgiEnv = new CGIEnvironment(req, getServletContext());

        if (cgiEnv.isValid()) {
            CGIRunner cgi = new CGIRunner(cgiEnv.getCommand(),
                                          cgiEnv.getEnvironment(),
                                          cgiEnv.getWorkingDirectory(),
                                          cgiEnv.getParameters());
            //if POST, we need to cgi.setInput
            //REMIND: how does this interact with Servlet API 2.3's Filters?!
            if ("POST".equals(req.getMethod())) {
                cgi.setInput(req.getInputStream());
            }
            cgi.setResponse(res);
            cgi.run();
        }

        if (!cgiEnv.isValid()) {
            res.setStatus(404);
        }
 
        if (debug >= 10) {

            ServletOutputStream out = res.getOutputStream();
            out.println("<HTML>");
            out.println("<BODY>$Header$
");

            if (cgiEnv.isValid()) {
                out.println(cgiEnv.toString());
            } else {
                out.println("<H3>");
                out.println("CGI script not found or not specified.");
                out.println("</H3>");
                out.println("<H4>");
                out.println("Check the <b>HttpServletRequest ");
                out.println("<a href=\"#pathInfo\">pathInfo ");
                out.println("property to see if it is what you meant ");
                out.println("it to be.  You must specify an existant ");
                out.println("and executable file as part of the ");
                out.println("path-info.");
                out.println("</H4>");
                out.println("<H4>");
                out.println("For a good discussion of how CGI scripts ");
                out.println("work and what their environment variables ");
                out.println("mean, please visit the <a ");
                out.println("href=\"http://cgi-spec.golux.com\">CGI ");
                out.println("Specification page</a>.");
                out.println("</H4>");

            }

            printServletEnvironment(out, req, res);

            out.println("</BODY>");

        }


    } //doGet



    /** For future testing use only; does nothing right now */
    public static void main(String[] args) {
        System.out.println("$Header$");
    }

    /**
     * Get all shell environment variables. Have to do it this rather ugly way
     * as the API to obtain is not available in 1.4 and earlier APIs.
     *
     * See <a href="http://www.rgagnon.com/javadetails/java-0150.html">Read environment
     * variables from an application</a> for original source and article.
     */
    private Hashtable<String,String> getShellEnvironment() throws IOException {
        Hashtable<String,String> envVars = new Hashtable();
        Process p = null;
        Runtime r = Runtime.getRuntime();
        String OS = System.getProperty("os.name").toLowerCase();
        boolean ignoreCase;

        if (OS.indexOf("windows 9") > -1) {
            p = r.exec( "command.com /c set" );
            ignoreCase = true;
        } else if ( (OS.indexOf("nt") > -1)
                || (OS.indexOf("windows 20") > -1)
                || (OS.indexOf("windows xp") > -1) ) {
            // thanks to JuanFran for the xp fix!
            p = r.exec( "cmd.exe /c set" );
            ignoreCase = true;
        } else {
            // our last hope, we assume Unix (thanks to H. Ware for the fix)
            p = r.exec( "env" );
            ignoreCase = false;
        }

        BufferedReader br = new BufferedReader
            ( new InputStreamReader( p.getInputStream() ) );
        String line;
        while( (line = br.readLine()) != null ) {
            int idx = line.indexOf( '=' );
            String key = line.substring( 0, idx );
            String value = line.substring( idx+1 );
            if (ignoreCase) {
                key = key.toUpperCase();
            }
            envVars.put(key, value);
        }
        return envVars;
    }







    /**
     * Encapsulates the CGI environment and rules to derive
     * that environment from the servlet container and request information.
     *
     * <p>
     * </p>
     *
     * @version  $Revision: 595801 $, $Date: 2007-11-16 21:07:07 +0100 (ven., 16 nov. 2007) $
     * @since    Tomcat 4.0
     *
     */
    protected class CGIEnvironment {


        /** context of the enclosing servlet */
        private ServletContext context = null;

        /** context path of enclosing servlet */
        private String contextPath = null;

        /** servlet URI of the enclosing servlet */
        private String servletPath = null;

        /** pathInfo for the current request */
        private String pathInfo = null;

        /** real file system directory of the enclosing servlet's web app */
        private String webAppRootDir = null;

        /** tempdir for context - used to expand scripts in unexpanded wars */
        private File tmpDir = null;

        /** derived cgi environment */
        private Hashtable env = null;

        /** cgi command to be invoked */
        private String command = null;

        /** cgi command's desired working directory */
        private File workingDirectory = null;

        /** cgi command's command line parameters */
        private ArrayList<String> cmdLineParameters = new ArrayList();

        /** whether or not this object is valid or not */
        private boolean valid = false;


        /**
         * Creates a CGIEnvironment and derives the necessary environment,
         * query parameters, working directory, cgi command, etc.
         *
         * @param  req       HttpServletRequest for information provided by
         *                   the Servlet API
         * @param  context   ServletContext for information provided by the
         *                   Servlet API
         *
         */
        protected CGIEnvironment(HttpServletRequest req,
                                 ServletContext context) throws IOException {
            setupFromContext(context);
            setupFromRequest(req);

            this.valid = setCGIEnvironment(req);

            if (this.valid) {
                workingDirectory = new File(command.substring(0,
                      command.lastIndexOf(File.separator)));
            }

        }



        /**
         * Uses the ServletContext to set some CGI variables
         *
         * @param  context   ServletContext for information provided by the
         *                   Servlet API
         */
        protected void setupFromContext(ServletContext context) {
            this.context = context;
            this.webAppRootDir = context.getRealPath("/");
            this.tmpDir = (File) context.getAttribute(Globals.WORK_DIR_ATTR);
        }



        /**
         * Uses the HttpServletRequest to set most CGI variables
         *
         * @param  req   HttpServletRequest for information provided by
         *               the Servlet API
         * @throws UnsupportedEncodingException 
         */
        protected void setupFromRequest(HttpServletRequest req)
                throws UnsupportedEncodingException {

            boolean isIncluded = false;

            // Look to see if this request is an include
            if (req.getAttribute(Globals.INCLUDE_REQUEST_URI_ATTR) != null) {
                isIncluded = true;
            }
            if (isIncluded) {
                this.contextPath = (String) req.getAttribute(
                        Globals.INCLUDE_CONTEXT_PATH_ATTR);
                this.servletPath = (String) req.getAttribute(
                        Globals.INCLUDE_SERVLET_PATH_ATTR);
                this.pathInfo = (String) req.getAttribute(
                        Globals.INCLUDE_PATH_INFO_ATTR);
            } else {
                this.contextPath = req.getContextPath();
                this.servletPath = req.getServletPath();
                this.pathInfo = req.getPathInfo();
            }
            // If getPathInfo() returns null, must be using extension mapping
            // In this case, pathInfo should be same as servletPath
            if (this.pathInfo == null) {
                this.pathInfo = this.servletPath;
            }

            // If the request method is GET, POST or HEAD and the query string
            // does not contain an unencoded "=" this is an indexed query.
            // The parsed query string becomes the command line parameters
            // for the cgi command.
            if (req.getMethod().equals("GET")
                || req.getMethod().equals("POST")
                || req.getMethod().equals("HEAD")) {
                String qs;
                if (isIncluded) {
                    qs = (String) req.getAttribute(
                            Globals.INCLUDE_QUERY_STRING_ATTR);
                } else {
                    qs = req.getQueryString();
                }
                if (qs != null && qs.indexOf("=") == -1) {
                    StringTokenizer qsTokens = new StringTokenizer(qs, "+");
                    while ( qsTokens.hasMoreTokens() ) {
                        cmdLineParameters.add(URLDecoder.decode(qsTokens.nextToken(),
                                              parameterEncoding));
                    }
                }
            }
        }


        /**
         * Resolves core information about the cgi script.
         *
         * <p>
         * Example URI:
         * <PRE> /servlet/cgigateway/dir1/realCGIscript/pathinfo1 

* <ul> * <LI>path = $CATALINA_HOME/mywebapp/dir1/realCGIscript * <LI>scriptName = /servlet/cgigateway/dir1/realCGIscript * <LI>cgiName = /dir1/realCGIscript * <LI>name = realCGIscript * </ul> * </p> * <p> * CGI search algorithm: search the real path below * <my-webapp-root> and find the first non-directory in * the getPathTranslated("/"), reading/searching from left-to-right. *</p> *<p> * The CGI search path will start at * webAppRootDir + File.separator + cgiPathPrefix * (or webAppRootDir alone if cgiPathPrefix is * null). *</p> *<p> * cgiPathPrefix is defined by setting * this servlet's cgiPathPrefix init parameter * *</p> * * @param pathInfo String from HttpServletRequest.getPathInfo() * @param webAppRootDir String from context.getRealPath("/") * @param contextPath String as from * HttpServletRequest.getContextPath() * @param servletPath String as from * HttpServletRequest.getServletPath() * @param cgiPathPrefix subdirectory of webAppRootDir below which * the web app's CGIs may be stored; can be null. * The CGI search path will start at * webAppRootDir + File.separator + cgiPathPrefix * (or webAppRootDir alone if cgiPathPrefix is * null). cgiPathPrefix is defined by setting * the servlet's cgiPathPrefix init parameter. * * * @return * <ul> * <li> * <code>path - full file-system path to valid cgi script, * or null if no cgi was found * <li> * <code>scriptName - * CGI variable SCRIPT_NAME; the full URL path * to valid cgi script or null if no cgi was * found * <li> * <code>cgiName - servlet pathInfo fragment corresponding to * the cgi script itself, or null if not found * <li> * <code>name - simple name (no directories) of the * cgi script, or null if no cgi was found * </ul> * * @since Tomcat 4.0 */ protected String[] findCGI(String pathInfo, String webAppRootDir, String contextPath, String servletPath, String cgiPathPrefix) { String path = null; String name = null; String scriptname = null; String cginame = ""; if ((webAppRootDir != null) && (webAppRootDir.lastIndexOf(File.separator) == (webAppRootDir.length() - 1))) { //strip the trailing "/" from the webAppRootDir webAppRootDir = webAppRootDir.substring(0, (webAppRootDir.length() - 1)); } if (cgiPathPrefix != null) { webAppRootDir = webAppRootDir + File.separator + cgiPathPrefix; } if (debug >= 2) { log("findCGI: path=" + pathInfo + ", " + webAppRootDir); } File currentLocation = new File(webAppRootDir); StringTokenizer dirWalker = new StringTokenizer(pathInfo, "/"); if (debug >= 3) { log("findCGI: currentLoc=" + currentLocation); } while (!currentLocation.isFile() && dirWalker.hasMoreElements()) { if (debug >= 3) { log("findCGI: currentLoc=" + currentLocation); } String nextElement = (String) dirWalker.nextElement(); currentLocation = new File(currentLocation, nextElement); cginame = cginame + "/" + nextElement; } if (!currentLocation.isFile()) { return new String[] { null, null, null, null }; } else { if (debug >= 2) { log("findCGI: FOUND cgi at " + currentLocation); } path = currentLocation.getAbsolutePath(); name = currentLocation.getName(); if (".".equals(contextPath)) { scriptname = servletPath; } else { scriptname = contextPath + servletPath; } if (!servletPath.equals(cginame)) { scriptname = scriptname + cginame; } } if (debug >= 1) { log("findCGI calc: name=" + name + ", path=" + path + ", scriptname=" + scriptname + ", cginame=" + cginame); } return new String[] { path, scriptname, cginame, name }; } /** * Constructs the CGI environment to be supplied to the invoked CGI * script; relies heavliy on Servlet API methods and findCGI * * @param req request associated with the CGI * invokation * * @return true if environment was set OK, false if there * was a problem and no environment was set */ protected boolean setCGIEnvironment(HttpServletRequest req) throws IOException { /* * This method is slightly ugly; c'est la vie. * "You cannot stop [ugliness], you can only hope to contain [it]" * (apologies to Marv Albert regarding MJ) */ Hashtable<String,String> envp = new Hashtable(); // Add the shell environment variables (if any) envp.putAll(shellEnv); // Add the CGI environment variables String sPathInfoOrig = null; String sPathTranslatedOrig = null; String sPathInfoCGI = null; String sPathTranslatedCGI = null; String sCGIFullPath = null; String sCGIScriptName = null; String sCGIFullName = null; String sCGIName = null; String[] sCGINames; sPathInfoOrig = this.pathInfo; sPathInfoOrig = sPathInfoOrig == null ? "" : sPathInfoOrig; sPathTranslatedOrig = req.getPathTranslated(); sPathTranslatedOrig = sPathTranslatedOrig == null ? "" : sPathTranslatedOrig; if (webAppRootDir == null ) { // The app has not been deployed in exploded form webAppRootDir = tmpDir.toString(); expandCGIScript(); } sCGINames = findCGI(sPathInfoOrig, webAppRootDir, contextPath, servletPath, cgiPathPrefix); sCGIFullPath = sCGINames[0]; sCGIScriptName = sCGINames[1]; sCGIFullName = sCGINames[2]; sCGIName = sCGINames[3]; if (sCGIFullPath == null || sCGIScriptName == null || sCGIFullName == null || sCGIName == null) { return false; } envp.put("SERVER_SOFTWARE", "TOMCAT"); envp.put("SERVER_NAME", nullsToBlanks(req.getServerName())); envp.put("GATEWAY_INTERFACE", "CGI/1.1"); envp.put("SERVER_PROTOCOL", nullsToBlanks(req.getProtocol())); int port = req.getServerPort(); Integer iPort = (port == 0 ? new Integer(-1) : new Integer(port)); envp.put("SERVER_PORT", iPort.toString()); envp.put("REQUEST_METHOD", nullsToBlanks(req.getMethod())); envp.put("REQUEST_URI", nullsToBlanks(req.getRequestURI())); /*- * PATH_INFO should be determined by using sCGIFullName: * 1) Let sCGIFullName not end in a "/" (see method findCGI) * 2) Let sCGIFullName equal the pathInfo fragment which * corresponds to the actual cgi script. * 3) Thus, PATH_INFO = request.getPathInfo().substring( * sCGIFullName.length()) * * (see method findCGI, where the real work is done) * */ if (pathInfo == null || (pathInfo.substring(sCGIFullName.length()).length() <= 0)) { sPathInfoCGI = ""; } else { sPathInfoCGI = pathInfo.substring(sCGIFullName.length()); } envp.put("PATH_INFO", sPathInfoCGI); /*- * PATH_TRANSLATED must be determined after PATH_INFO (and the * implied real cgi-script) has been taken into account. * * The following example demonstrates: * * servlet info = /servlet/cgigw/dir1/dir2/cgi1/trans1/trans2 * cgifullpath = /servlet/cgigw/dir1/dir2/cgi1 * path_info = /trans1/trans2 * webAppRootDir = servletContext.getRealPath("/") * * path_translated = servletContext.getRealPath("/trans1/trans2") * * That is, PATH_TRANSLATED = webAppRootDir + sPathInfoCGI * (unless sPathInfoCGI is null or blank, then the CGI * specification dictates that the PATH_TRANSLATED metavariable * SHOULD NOT be defined. * */ if (sPathInfoCGI != null && !("".equals(sPathInfoCGI))) { sPathTranslatedCGI = context.getRealPath(sPathInfoCGI); } else { sPathTranslatedCGI = null; } if (sPathTranslatedCGI == null || "".equals(sPathTranslatedCGI)) { //NOOP } else { envp.put("PATH_TRANSLATED", nullsToBlanks(sPathTranslatedCGI)); } envp.put("SCRIPT_NAME", nullsToBlanks(sCGIScriptName)); envp.put("QUERY_STRING", nullsToBlanks(req.getQueryString())); envp.put("REMOTE_HOST", nullsToBlanks(req.getRemoteHost())); envp.put("REMOTE_ADDR", nullsToBlanks(req.getRemoteAddr())); envp.put("AUTH_TYPE", nullsToBlanks(req.getAuthType())); envp.put("REMOTE_USER", nullsToBlanks(req.getRemoteUser())); envp.put("REMOTE_IDENT", ""); //not necessary for full compliance envp.put("CONTENT_TYPE", nullsToBlanks(req.getContentType())); /* Note CGI spec says CONTENT_LENGTH must be NULL ("") or undefined * if there is no content, so we cannot put 0 or -1 in as per the * Servlet API spec. */ int contentLength = req.getContentLength(); String sContentLength = (contentLength <= 0 ? "" : (new Integer(contentLength)).toString()); envp.put("CONTENT_LENGTH", sContentLength); Enumeration headers = req.getHeaderNames(); String header = null; while (headers.hasMoreElements()) { header = null; header = ((String) headers.nextElement()).toUpperCase(); //REMIND: rewrite multiple headers as if received as single //REMIND: change character set //REMIND: I forgot what the previous REMIND means if ("AUTHORIZATION".equalsIgnoreCase(header) || "PROXY_AUTHORIZATION".equalsIgnoreCase(header)) { //NOOP per CGI specification section 11.2 } else { envp.put("HTTP_" + header.replace('-', '_'), req.getHeader(header)); } } File fCGIFullPath = new File(sCGIFullPath); command = fCGIFullPath.getCanonicalPath(); envp.put("X_TOMCAT_SCRIPT_PATH", command); //for kicks envp.put("SCRIPT_FILENAME", command); //for PHP this.env = envp; return true; } /** * Extracts requested resource from web app archive to context work * directory to enable CGI script to be executed. */ protected void expandCGIScript() { StringBuffer srcPath = new StringBuffer(); StringBuffer destPath = new StringBuffer(); InputStream is = null; // paths depend on mapping if (cgiPathPrefix == null ) { srcPath.append(pathInfo); is = context.getResourceAsStream(srcPath.toString()); destPath.append(tmpDir); destPath.append(pathInfo); } else { // essentially same search algorithm as findCGI() srcPath.append(cgiPathPrefix); StringTokenizer pathWalker = new StringTokenizer (pathInfo, "/"); // start with first element while (pathWalker.hasMoreElements() && (is == null)) { srcPath.append("/"); srcPath.append(pathWalker.nextElement()); is = context.getResourceAsStream(srcPath.toString()); } destPath.append(tmpDir); destPath.append("/"); destPath.append(srcPath); } if (is == null) { // didn't find anything, give up now if (debug >= 2) { log("expandCGIScript: source '" + srcPath + "' not found"); } return; } File f = new File(destPath.toString()); if (f.exists()) { // Don't need to expand if it already exists return; } // create directories String dirPath = new String (destPath.toString().substring( 0,destPath.toString().lastIndexOf("/"))); File dir = new File(dirPath); dir.mkdirs(); try { synchronized (expandFileLock) { // make sure file doesn't exist if (f.exists()) { return; } // create file if (!f.createNewFile()) { return; } FileOutputStream fos = new FileOutputStream(f); // copy data IOTools.flow(is, fos); is.close(); fos.close(); if (debug >= 2) { log("expandCGIScript: expanded '" + srcPath + "' to '" + destPath + "'"); } } } catch (IOException ioe) { // delete in case file is corrupted if (f.exists()) { f.delete(); } } } /** * Print important CGI environment information in a easy-to-read HTML * table * * @return HTML string containing CGI environment info * */ public String toString() { StringBuffer sb = new StringBuffer(); sb.append("<TABLE border=2>"); sb.append("<tr>