[apache] / server / util_script.c

/* ====================================================================
 * Copyright (c) 1995-1999 The Apache Group.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * 4. The names "Apache Server" and "Apache Group" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Group and was originally based
 * on public domain software written at the National Center for
 * Supercomputing Applications, University of Illinois, Urbana-Champaign.
 * For more information on the Apache Group and the Apache HTTP server
 * project, please see <http://www.apache.org/>.
 *
 */

#define CORE_PRIVATE
#include "httpd.h"
#include "http_config.h"
#include "http_main.h"
#include "http_log.h"
#include "http_core.h"
#include "http_protocol.h"
#include "http_request.h"       /* for sub_req_lookup_uri() */
#include "util_script.h"
#include "util_date.h"          /* For parseHTTPdate() */

#ifdef OS2
#define INCL_DOS
#include <os2.h>
#endif

/*
 * Various utility functions which are common to a whole lot of
 * script-type extensions mechanisms, and might as well be gathered
 * in one place (if only to avoid creating inter-module dependancies
 * where there don't have to be).
 */

#define MALFORMED_MESSAGE "malformed header from script. Bad header="
#define MALFORMED_HEADER_LENGTH_TO_SHOW 30

/* If a request includes query info in the URL (stuff after "?"), and
 * the query info does not contain "=" (indicative of a FORM submission),
 * then this routine is called to create the argument list to be passed
 * to the CGI script.  When suexec is enabled, the suexec path, user, and
 * group are the first three arguments to be passed; if not, all three
 * must be NULL.  The query info is split into separate arguments, where
 * "+" is the separator between keyword arguments.
 *
 * XXXX: note that the WIN32 code uses one of the suexec strings 
 * to pass an interpreter name.  Remember this if changing the way they
 * are handled in create_argv.
 *
 */
static char **create_argv(ap_context_t *p, char *path, char *user, char *group,
                          char *av0, const char *args)
{
    int x, numwords;
    char **av;
    char *w;
    int idx = 0;

    /* count the number of keywords */

    for (x = 0, numwords = 1; args[x]; x++) {
        if (args[x] == '+') {
            ++numwords;
        }
    }

    if (numwords > APACHE_ARG_MAX - 5) {
        numwords = APACHE_ARG_MAX - 5;  /* Truncate args to prevent overrun */
    }
    av = (char **) ap_palloc(p, (numwords + 5) * sizeof(char *));

    if (path) {
        av[idx++] = path;
    }
    if (user) {
        av[idx++] = user;
    }
    if (group) {
        av[idx++] = group;
    }

    av[idx++] = av0;

    for (x = 1; x <= numwords; x++) {
        w = ap_getword_nulls(p, &args, '+');
        ap_unescape_url(w);
        av[idx++] = ap_escape_shell_cmd(p, w);
    }
    av[idx] = NULL;
    return av;
}


static char *http2env(ap_context_t *a, char *w)
{
    char *res = ap_pstrcat(a, "HTTP_", w, NULL);
    char *cp = res;

    while (*++cp) {
        if (!ap_isalnum(*cp) && *cp != '_') {
            *cp = '_';
        }
        else {
            *cp = ap_toupper(*cp);
        }
    }

    return res;
}

API_EXPORT(char **) ap_create_environment(ap_context_t *p, ap_table_t *t)
{
    ap_array_header_t *env_arr = ap_table_elts(t);
    ap_table_entry_t *elts = (ap_table_entry_t *) env_arr->elts;
    char **env = (char **) ap_palloc(p, (env_arr->nelts + 2) * sizeof(char *));
    int i, j;
    char *tz;
    char *whack;

    j = 0;
    if (!ap_table_get(t, "TZ")) {
        tz = getenv("TZ");
        if (tz != NULL) {
            env[j++] = ap_pstrcat(p, "TZ=", tz, NULL);
        }
    }
    for (i = 0; i < env_arr->nelts; ++i) {
        if (!elts[i].key) {
            continue;
        }
        env[j] = ap_pstrcat(p, elts[i].key, "=", elts[i].val, NULL);
        whack = env[j];
        if (ap_isdigit(*whack)) {
            *whack++ = '_';
        }
        while (*whack != '=') {
            if (!ap_isalnum(*whack) && *whack != '_') {
                *whack = '_';
            }
            ++whack;
        }
        ++j;
    }

    env[j] = NULL;
    return env;
}

API_EXPORT(void) ap_add_common_vars(request_rec *r)
{
    ap_table_t *e;
    server_rec *s = r->server;
    conn_rec *c = r->connection;
    const char *rem_logname;
    char *env_path;
#ifdef WIN32
    char *env_temp;
#endif
    const char *host;
    ap_array_header_t *hdrs_arr = ap_table_elts(r->headers_in);
    ap_table_entry_t *hdrs = (ap_table_entry_t *) hdrs_arr->elts;
    int i;

    /* use a temporary ap_table_t which we'll overlap onto
     * r->subprocess_env later
     */
    e = ap_make_table(r->pool, 25 + hdrs_arr->nelts);

    /* First, add environment vars from headers... this is as per
     * CGI specs, though other sorts of scripting interfaces see
     * the same vars...
     */

    for (i = 0; i < hdrs_arr->nelts; ++i) {
        if (!hdrs[i].key) {
            continue;
        }

        /* A few headers are special cased --- Authorization to prevent
         * rogue scripts from capturing passwords; content-type and -length
         * for no particular reason.
         */

        if (!strcasecmp(hdrs[i].key, "Content-type")) {
            ap_table_addn(e, "CONTENT_TYPE", hdrs[i].val);
        }
        else if (!strcasecmp(hdrs[i].key, "Content-length")) {
            ap_table_addn(e, "CONTENT_LENGTH", hdrs[i].val);
        }
        /*
         * You really don't want to disable this check, since it leaves you
         * wide open to CGIs stealing passwords and people viewing them
         * in the environment with "ps -e".  But, if you must...
         */
#ifndef SECURITY_HOLE_PASS_AUTHORIZATION
        else if (!strcasecmp(hdrs[i].key, "Authorization") 
                 || !strcasecmp(hdrs[i].key, "Proxy-Authorization")) {
            continue;
        }
#endif
        else {
            ap_table_addn(e, http2env(r->pool, hdrs[i].key), hdrs[i].val);
        }
    }

    if (!(env_path = getenv("PATH"))) {
        env_path = DEFAULT_PATH;
    }

#ifdef WIN32
    if (env_temp = getenv("SystemRoot")) {
        ap_table_addn(e, "SystemRoot", env_temp);         
    }
    if (env_temp = getenv("COMSPEC")) {
        ap_table_addn(e, "COMSPEC", env_temp);            
    }
    if (env_temp = getenv("WINDIR")) {
        ap_table_addn(e, "WINDIR", env_temp);
    }
#endif

    ap_table_addn(e, "PATH", env_path);
    ap_table_addn(e, "SERVER_SIGNATURE", ap_psignature("", r));
    ap_table_addn(e, "SERVER_SOFTWARE", ap_get_server_version());
    ap_table_addn(e, "SERVER_NAME", ap_get_server_name(r));
    ap_table_addn(e, "SERVER_ADDR", r->connection->local_ip);   /* Apache */
    ap_table_addn(e, "SERVER_PORT",
                  ap_psprintf(r->pool, "%u", ap_get_server_port(r)));
    host = ap_get_remote_host(c, r->per_dir_config, REMOTE_HOST);
    if (host) {
        ap_table_addn(e, "REMOTE_HOST", host);
    }
    ap_table_addn(e, "REMOTE_ADDR", c->remote_ip);
    ap_table_addn(e, "DOCUMENT_ROOT", ap_document_root(r));     /* Apache */
    ap_table_addn(e, "SERVER_ADMIN", s->server_admin);  /* Apache */
    ap_table_addn(e, "SCRIPT_FILENAME", r->filename);   /* Apache */

    ap_table_addn(e, "REMOTE_PORT",
                  ap_psprintf(r->pool, "%d", ntohs(c->remote_addr.sin_port)));

    if (r->user) {
        ap_table_addn(e, "REMOTE_USER", r->user);
    }
    if (r->ap_auth_type) {
        ap_table_addn(e, "AUTH_TYPE", r->ap_auth_type);
    }
    rem_logname = ap_get_remote_logname(r);
    if (rem_logname) {
        ap_table_addn(e, "REMOTE_IDENT", ap_pstrdup(r->pool, rem_logname));
    }

    /* Apache custom error responses. If we have redirected set two new vars */

    if (r->prev) {
        if (r->prev->args) {
            ap_table_addn(e, "REDIRECT_QUERY_STRING", r->prev->args);
        }
        if (r->prev->uri) {
            ap_table_addn(e, "REDIRECT_URL", r->prev->uri);
        }
    }

    ap_overlap_tables(r->subprocess_env, e, AP_OVERLAP_TABLES_SET);
}

/* This "cute" little function comes about because the path info on
 * filenames and URLs aren't always the same. So we take the two,
 * and find as much of the two that match as possible.
 */

API_EXPORT(int) ap_find_path_info(const char *uri, const char *path_info)
{
    int lu = strlen(uri);
    int lp = strlen(path_info);

    while (lu-- && lp-- && uri[lu] == path_info[lp]);

    if (lu == -1) {
        lu = 0;
    }

    while (uri[lu] != '\0' && uri[lu] != '/') {
        lu++;
    }
    return lu;
}

/* Obtain the Request-URI from the original request-line, returning
 * a new string from the request ap_context_t containing the URI or "".
 */
static char *original_uri(request_rec *r)
{
    char *first, *last;

    if (r->the_request == NULL) {
        return (char *) ap_pcalloc(r->pool, 1);
    }

    first = r->the_request;     /* use the request-line */

    while (*first && !ap_isspace(*first)) {
        ++first;                /* skip over the method */
    }
    while (ap_isspace(*first)) {
        ++first;                /*   and the space(s)   */
    }

    last = first;
    while (*last && !ap_isspace(*last)) {
        ++last;                 /* end at next whitespace */
    }

    return ap_pstrndup(r->pool, first, last - first);
}

API_EXPORT(void) ap_add_cgi_vars(request_rec *r)
{
    ap_table_t *e = r->subprocess_env;

    ap_table_setn(e, "GATEWAY_INTERFACE", "CGI/1.1");
    ap_table_setn(e, "SERVER_PROTOCOL", r->protocol);
    ap_table_setn(e, "REQUEST_METHOD", r->method);
    ap_table_setn(e, "QUERY_STRING", r->args ? r->args : "");
    ap_table_setn(e, "REQUEST_URI", original_uri(r));

    /* Note that the code below special-cases scripts run from includes,
     * because it "knows" that the sub_request has been hacked to have the
     * args and path_info of the original request, and not any that may have
     * come with the script URI in the include command.  Ugh.
     */

    if (!strcmp(r->protocol, "INCLUDED")) {
        ap_table_setn(e, "SCRIPT_NAME", r->uri);
        if (r->path_info && *r->path_info) {
            ap_table_setn(e, "PATH_INFO", r->path_info);
        }
    }
    else if (!r->path_info || !*r->path_info) {
        ap_table_setn(e, "SCRIPT_NAME", r->uri);
    }
    else {
        int path_info_start = ap_find_path_info(r->uri, r->path_info);

        ap_table_setn(e, "SCRIPT_NAME",
                      ap_pstrndup(r->pool, r->uri, path_info_start));

        ap_table_setn(e, "PATH_INFO", r->path_info);
    }

    if (r->path_info && r->path_info[0]) {
        /*
         * To get PATH_TRANSLATED, treat PATH_INFO as a URI path.
         * Need to re-escape it for this, since the entire URI was
         * un-escaped before we determined where the PATH_INFO began.
         */
        request_rec *pa_req;

        pa_req = ap_sub_req_lookup_uri(ap_escape_uri(r->pool, r->path_info), r);

        if (pa_req->filename) {
#ifdef WIN32
            char buffer[HUGE_STRING_LEN];
#endif
            char *pt = ap_pstrcat(r->pool, pa_req->filename, pa_req->path_info,
                                  NULL);
#ifdef WIN32
            /* We need to make this a real Windows path name */
            GetFullPathName(pt, HUGE_STRING_LEN, buffer, NULL);
            ap_table_setn(e, "PATH_TRANSLATED", ap_pstrdup(r->pool, buffer));
#else
            ap_table_setn(e, "PATH_TRANSLATED", pt);
#endif
        }
        ap_destroy_sub_req(pa_req);
    }
}


static int set_cookie_doo_doo(void *v, const char *key, const char *val)
{
    ap_table_addn(v, key, val);
    return 1;
}

API_EXPORT(int) ap_scan_script_header_err_core(request_rec *r, char *buffer,
                                       int (*getsfunc) (char *, int, void *),
                                       void *getsfunc_data)
{
    char x[MAX_STRING_LEN];
    char *w, *l;
    int p;
    int cgi_status = HTTP_OK;
    ap_table_t *merge;
    ap_table_t *cookie_table;

    if (buffer) {
        *buffer = '\0';
    }
    w = buffer ? buffer : x;

    /* temporary place to hold headers to merge in later */
    merge = ap_make_table(r->pool, 10);

    /* The HTTP specification says that it is legal to merge duplicate
     * headers into one.  Some browsers that support Cookies don't like
     * merged headers and prefer that each Set-Cookie header is sent
     * separately.  Lets humour those browsers by not merging.
     * Oh what a pain it is.
     */
    cookie_table = ap_make_table(r->pool, 2);
    ap_table_do(set_cookie_doo_doo, cookie_table, r->err_headers_out, "Set-Cookie", NULL);

    while (1) {

        if ((*getsfunc) (w, MAX_STRING_LEN - 1, getsfunc_data) == 0) {
            ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                          "Premature end of script headers: %s", r->filename);
            return HTTP_INTERNAL_SERVER_ERROR;
        }

        /* Delete terminal (CR?)LF */

        p = strlen(w);
        if (p > 0 && w[p - 1] == '\n') {
            if (p > 1 && w[p - 2] == '\015') {
                w[p - 2] = '\0';
            }
            else {
                w[p - 1] = '\0';
            }
        }

        /*
         * If we've finished reading the headers, check to make sure any
         * HTTP/1.1 conditions are met.  If so, we're done; normal processing
         * will handle the script's output.  If not, just return the error.
         * The appropriate thing to do would be to send the script process a
         * SIGPIPE to let it know we're ignoring it, close the channel to the
         * script process, and *then* return the failed-to-meet-condition
         * error.  Otherwise we'd be waiting for the script to finish
         * blithering before telling the client the output was no good.
         * However, we don't have the information to do that, so we have to
         * leave it to an upper layer.
         */
        if (w[0] == '\0') {
            int cond_status = OK;

            if ((cgi_status == HTTP_OK) && (r->method_number == M_GET)) {
                cond_status = ap_meets_conditions(r);
            }
            ap_overlap_tables(r->err_headers_out, merge,
                AP_OVERLAP_TABLES_MERGE);
            if (!ap_is_empty_table(cookie_table)) {
                /* the cookies have already been copied to the cookie_table */
                ap_table_unset(r->err_headers_out, "Set-Cookie");
                r->err_headers_out = ap_overlay_tables(r->pool,
                    r->err_headers_out, cookie_table);
            }
            return cond_status;
        }

        /* if we see a bogus header don't ignore it. Shout and scream */

#ifdef CHARSET_EBCDIC
            /* Chances are that we received an ASCII header text instead of
             * the expected EBCDIC header lines. Try to auto-detect:
             */
        if (!(l = strchr(w, ':'))) {
            int maybeASCII = 0, maybeEBCDIC = 0;
            char *cp;

            for (cp = w; *cp != '\0'; ++cp) {
                if (isprint(*cp) && !isprint(os_toebcdic[*cp]))
                    ++maybeEBCDIC;
                if (!isprint(*cp) && isprint(os_toebcdic[*cp]))
                    ++maybeASCII;
                }
            if (maybeASCII > maybeEBCDIC) {
                ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r->server,
                         "CGI Interface Error: Script headers apparently ASCII: (CGI = %s)", r->filename);
                ascii2ebcdic(w, w, cp - w);
            }
        }
#endif
        if (!(l = strchr(w, ':'))) {
            char malformed[(sizeof MALFORMED_MESSAGE) + 1
                           + MALFORMED_HEADER_LENGTH_TO_SHOW];

            strcpy(malformed, MALFORMED_MESSAGE);
            strncat(malformed, w, MALFORMED_HEADER_LENGTH_TO_SHOW);

            if (!buffer) {
                /* Soak up all the script output - may save an outright kill */
                while ((*getsfunc) (w, MAX_STRING_LEN - 1, getsfunc_data)) {
                    continue;
                }
            }

            ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                          "%s: %s", malformed, r->filename);
            return HTTP_INTERNAL_SERVER_ERROR;
        }

        *l++ = '\0';
        while (*l && ap_isspace(*l)) {
            ++l;
        }

        if (!strcasecmp(w, "Content-type")) {
            char *tmp;

            /* Nuke trailing whitespace */

            char *endp = l + strlen(l) - 1;
            while (endp > l && ap_isspace(*endp)) {
                *endp-- = '\0';
            }

            tmp = ap_pstrdup(r->pool, l);
            ap_content_type_tolower(tmp);
            r->content_type = tmp;
        }
        /*
         * If the script returned a specific status, that's what
         * we'll use - otherwise we assume 200 OK.
         */
        else if (!strcasecmp(w, "Status")) {
            r->status = cgi_status = atoi(l);
            r->status_line = ap_pstrdup(r->pool, l);
        }
        else if (!strcasecmp(w, "Location")) {
            ap_table_set(r->headers_out, w, l);
        }
        else if (!strcasecmp(w, "Content-Length")) {
            ap_table_set(r->headers_out, w, l);
        }
        else if (!strcasecmp(w, "Transfer-Encoding")) {
            ap_table_set(r->headers_out, w, l);
        }
        /*
         * If the script gave us a Last-Modified header, we can't just
         * pass it on blindly because of restrictions on future values.
         */
        else if (!strcasecmp(w, "Last-Modified")) {
            time_t mtime = ap_parseHTTPdate(l);

            ap_update_mtime(r, mtime);
            ap_set_last_modified(r);
        }
        else if (!strcasecmp(w, "Set-Cookie")) {
            ap_table_add(cookie_table, w, l);
        }
        else {
            ap_table_add(merge, w, l);
        }
    }
}

static int getsfunc_FILE(char *buf, int len, void *f)
{
    return fgets(buf, len, (FILE *) f) != NULL;
}

API_EXPORT(int) ap_scan_script_header_err(request_rec *r, FILE *f,
                                          char *buffer)
{
    return ap_scan_script_header_err_core(r, buffer, getsfunc_FILE, f);
}

static int getsfunc_BUFF(char *w, int len, void *fb)
{
    return ap_bgets(w, len, (BUFF *) fb) > 0;
}

API_EXPORT(int) ap_scan_script_header_err_buff(request_rec *r, BUFF *fb,
                                               char *buffer)
{
    return ap_scan_script_header_err_core(r, buffer, getsfunc_BUFF, fb);
}


API_EXPORT(void) ap_send_size(size_t size, request_rec *r)
{
    /* XXX: this -1 thing is a gross hack */
    if (size == (size_t)-1) {
        ap_rputs("    -", r);
    }
    else if (!size) {
        ap_rputs("   0k", r);
    }
    else if (size < 1024) {
        ap_rputs("   1k", r);
    }
    else if (size < 1048576) {
        ap_rprintf(r, "%4dk", (size + 512) / 1024);
    }
    else if (size < 103809024) {
        ap_rprintf(r, "%4.1fM", size / 1048576.0);
    }
    else {
        ap_rprintf(r, "%4dM", (size + 524288) / 1048576);
    }
}

#if defined(OS2) || defined(WIN32)
static char **create_argv_cmd(ap_context_t *p, char *av0, const char *args, char *path)
{
    register int x, n;
    char **av;
    char *w;

    for (x = 0, n = 2; args[x]; x++) {
        if (args[x] == '+') {
            ++n;
        }
    }

    /* Add extra strings to array. */
    n = n + 2;

    av = (char **) ap_palloc(p, (n + 1) * sizeof(char *));
    av[0] = av0;

    /* Now insert the extra strings we made room for above. */
    av[1] = strdup("/C");
    av[2] = strdup(path);

    for (x = (1 + 2); x < n; x++) {
        w = ap_getword(p, &args, '+');
        ap_unescape_url(w);
        av[x] = ap_escape_shell_cmd(p, w);
    }
    av[n] = NULL;
    return av;
}
#endif

/* ZZZ need to look at this in more depth and convert to an AP func so we 
   can get rid of OS specific code.
   */
API_EXPORT(int) ap_call_exec(request_rec *r, ap_child_info_t *pinfo, char *argv0,
                             char **env, int shellcmd)
{
    int pid = 0;

#if !defined(WIN32) && !defined(OS2)
    /* the fd on r->server->error_log is closed, but we need somewhere to
     * put the error messages from the log_* functions. So, we use stderr,
     * since that is better than allowing errors to go unnoticed.  Don't do
     * this on Win32, though, since we haven't fork()'d.
     */
    r->server->error_log = stderr;
#endif

    /* TODO: all that RLimit stuff should become part of the spawning API,
     * and not something in the core_dir_config... define a special rlimit
     * structure and pass it in here.
     */

#ifdef OS2
    {
        /* Additions by Alec Kloss, to allow exec'ing of scripts under OS/2 */
        int is_script = 0;
        char interpreter[2048]; /* hope it's enough for the interpreter path */
        char error_object[260];
        FILE *program;
        char *cmdline = r->filename, *cmdline_pos;
        int cmdlen;
        char *args = "", *args_end;
        ULONG rc;
        RESULTCODES rescodes;
        int env_len, e;
        char *env_block, *env_block_pos;

        if (r->args && r->args[0] && !strchr(r->args, '='))
            args = r->args;
            
        program = fopen(r->filename, "rt");
        
        if (!program) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, r, "fopen(%s) failed",
                         r->filename);
            return (pid);
        }
        
        fgets(interpreter, sizeof(interpreter), program);
        fclose(program);
        
        if (!strncmp(interpreter, "#!", 2)) {
            is_script = 1;
            interpreter[strlen(interpreter) - 1] = '\0';
            if (interpreter[2] != '/' && interpreter[2] != '\\' && interpreter[3] != ':') {
                char buffer[300];
                if (DosSearchPath(SEARCH_ENVIRONMENT, "PATH", interpreter+2, buffer, sizeof(buffer)) == 0) {
                    strcpy(interpreter+2, buffer);
                } else {
                    strcat(interpreter, ".exe");
                    if (DosSearchPath(SEARCH_ENVIRONMENT, "PATH", interpreter+2, buffer, sizeof(buffer)) == 0) {
                        strcpy(interpreter+2, buffer);
                    }
                }
            }
        }

        if (is_script) {
            cmdline = ap_pstrcat(r->pool, interpreter+2, " ", r->filename, NULL);
        }
        else if (strstr(strupr(r->filename), ".CMD") > 0) {
            /* Special case to allow use of REXX commands as scripts. */
            os2pathname(r->filename);
            cmdline = ap_pstrcat(r->pool, SHELL_PATH, " /C ", r->filename, NULL);
        }
        else {
            cmdline = r->filename;
        }
        
        args = ap_pstrdup(r->pool, args);
        ap_unescape_url(args);
        args = ap_double_quotes(r->pool, args);
        args_end = args + strlen(args);

        if (args_end - args > 4000) { /* cmd.exe won't handle lines longer than 4k */
            args_end = args + 4000;
            *args_end = 0;
        }

        /* +4 = 1 space between progname and args, 2 for double null at end, 2 for possible quote on first arg */
        cmdlen = strlen(cmdline) + strlen(args) + 4; 
        cmdline_pos = cmdline;

        while (*cmdline_pos) {
            cmdlen += 2 * (*cmdline_pos == '+');  /* Allow space for each arg to be quoted */
            cmdline_pos++;
        }

        cmdline = ap_pstrndup(r->pool, cmdline, cmdlen);
        cmdline_pos = cmdline + strlen(cmdline);

        while (args < args_end) {
            char *arg;
            
            arg = ap_getword_nc(r->pool, &args, '+');

            if (strpbrk(arg, "&|<> "))
                arg = ap_pstrcat(r->pool, "\"", arg, "\"", NULL);

            *(cmdline_pos++) = ' ';
            strcpy(cmdline_pos, arg);
            cmdline_pos += strlen(cmdline_pos);
        }

        *(++cmdline_pos) = 0; /* Add required second terminator */
        args = strchr(cmdline, ' ');
        
        if (args) {
            *args = 0;
            args++;
        }

        /* Create environment block from list of envariables */
        for (env_len=1, e=0; env[e]; e++)
            env_len += strlen(env[e]) + 1;

        env_block = ap_palloc(r->pool, env_len);
        env_block_pos = env_block;

        for (e=0; env[e]; e++) {
            strcpy(env_block_pos, env[e]);
            env_block_pos += strlen(env_block_pos) + 1;
        }

        *env_block_pos = 0; /* environment block is terminated by a double null */

        rc = DosExecPgm(error_object, sizeof(error_object), EXEC_ASYNC, cmdline, env_block, &rescodes, cmdline);
        
        if (rc) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, r, "DosExecPgm(%s %s) failed, %s - %s",
                          cmdline, args ? args : "", ap_os_error_message(rc), error_object );
            return -1;
        }
        
        return rescodes.codeTerminate;
    }
#elif defined(WIN32)
    {
        /* Adapted from Alec Kloss' work for OS/2 */
        char *interpreter = NULL;
        char *arguments = NULL;
        char *ext = NULL;
        char *exename = NULL;
        char *s = NULL;
        char *quoted_filename;
        char *pCommand;
        char *pEnvBlock, *pNext;

        int i;
        int iEnvBlockLen;

        file_type_e fileType;

        STARTUPINFO si;
        PROCESS_INFORMATION pi;

        memset(&si, 0, sizeof(si));
        memset(&pi, 0, sizeof(pi));

        pid = -1;

        if (!shellcmd) {

            fileType = ap_get_win32_interpreter(r, &interpreter);

            if (fileType == eFileTypeUNKNOWN) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, r,
                              "%s is not executable; ensure interpreted scripts have "
                              "\"#!\" first line", 
                              r->filename);
                return (pid);
            }

            /*
             * Look at the arguments...
             */
            arguments = "";
            if ((r->args) && (r->args[0]) && !strchr(r->args, '=')) { 
                /* If we are in this leg, there are some other arguments
                 * that we must include in the execution of the CGI.
                 * Because CreateProcess is the way it is, we have to
                 * create a command line like format for the execution
                 * of the CGI.  This means we need to create on long
                 * string with the executable and arguments.
                 *
                 * The arguments string comes in the request structure,
                 * and each argument is separated by a '+'.  We'll replace
                 * these pluses with spaces.
                 */

                int iStringSize = 0;
                int x;
            
                /*
                 *  Duplicate the request structure string so we don't change it.
                 */                                   
                arguments = ap_pstrdup(r->pool, r->args);
                
                /*
                 *  Change the '+' to ' '
                 */
                for (x=0; arguments[x]; x++) {
                    if ('+' == arguments[x]) {
                        arguments[x] = ' ';
                    }
                }
       
                /*
                 * We need to unescape any characters that are 
                 * in the arguments list.
                 */
                ap_unescape_url(arguments);
                arguments = ap_escape_shell_cmd(r->pool, arguments);
            }

            /*
             * We have the interpreter (if there is one) and we have 
             * the arguments (if there are any).
             * Build the command string to pass to CreateProcess. 
             */
            quoted_filename = ap_pstrcat(r->pool, "\"", r->filename, "\"", NULL);
            if (interpreter && *interpreter) {
                pCommand = ap_pstrcat(r->pool, interpreter, " ", 
                                      quoted_filename, " ", arguments, NULL);
            }
            else {
                pCommand = ap_pstrcat(r->pool, quoted_filename, " ", arguments, NULL);
            }

         } else {

            char *shell_cmd = "CMD.EXE /C ";
            OSVERSIONINFO osver;
            osver.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
         
            /*
             * Use CMD.EXE for NT, COMMAND.COM for WIN95
             */
            if (GetVersionEx(&osver)) {
                if (osver.dwPlatformId != VER_PLATFORM_WIN32_NT) {
                    shell_cmd = "COMMAND.COM /C ";
                }
            }       
            pCommand = ap_pstrcat(r->pool, shell_cmd, argv0, NULL);
        }

        /*
         * Make child process use hPipeOutputWrite as standard out,
         * and make sure it does not show on screen.
         */
        si.cb = sizeof(si);
        si.dwFlags     = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
        si.wShowWindow = SW_HIDE;
        si.hStdInput   = pinfo->hPipeInputRead;
        si.hStdOutput  = pinfo->hPipeOutputWrite;
        si.hStdError   = pinfo->hPipeErrorWrite;
  
        /*
         * Win32's CreateProcess call requires that the environment
         * be passed in an environment block, a null terminated block of
         * null terminated strings.
         */  
        i = 0;
        iEnvBlockLen = 1;
        while (env[i]) {
            iEnvBlockLen += strlen(env[i]) + 1;
            i++;
        }
  
        pEnvBlock = (char *)ap_pcalloc(r->pool,iEnvBlockLen);
    
        i = 0;
        pNext = pEnvBlock;
        while (env[i]) {
            strcpy(pNext, env[i]);
            pNext = pNext + strlen(pNext) + 1;
            i++;
        }

        if (CreateProcess(NULL, pCommand, NULL, NULL, TRUE, DETACHED_PROCESS, pEnvBlock,
                          ap_make_dirstr_parent(r->pool, r->filename),
                          &si, &pi)) {
            if (fileType == eFileTypeEXE16) {
                /* Hack to get 16-bit CGI's working. It works for all the 
                 * standard modules shipped with Apache. pi.dwProcessId is 0 
                 * for 16-bit CGIs and all the Unix specific code that calls 
                 * ap_call_exec interprets this as a failure case. And we can't 
                 * use -1 either because it is mapped to 0 by the caller.
                 */
                pid = -2;
            }
            else {
                pid = pi.dwProcessId;
                /*
                 * We must close the handles to the new process and its main thread
                 * to prevent handle and memory leaks.
                 */ 
                CloseHandle(pi.hProcess);
                CloseHandle(pi.hThread);
            }
        }
        return (pid);
    }

#else
    /* TODO: re ap_context_t mplement suexec */
#if 0
    if (ap_suexec_enabled
        && ((r->server->server_uid != ap_user_id)
            || (r->server->server_gid != ap_group_id)
            || (!strncmp("/~", r->uri, 2)))) {

        char *execuser, *grpname;
        struct passwd *pw;
        struct group *gr;

        if (!strncmp("/~", r->uri, 2)) {
            gid_t user_gid;
            char *username = ap_pstrdup(r->pool, r->uri + 2);
            char *pos = strchr(username, '/');

            if (pos) {
                *pos = '\0';
            }

            if ((pw = getpwnam(username)) == NULL) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
                             "getpwnam: invalid username %s", username);
                return (pid);
            }
            execuser = ap_pstrcat(r->pool, "~", pw->pw_name, NULL);
            user_gid = pw->pw_gid;

            if ((gr = getgrgid(user_gid)) == NULL) {
                if ((grpname = ap_palloc(r->pool, 16)) == NULL) {
                    return (pid);
                }
                else {
                    ap_snprintf(grpname, 16, "%ld", (long) user_gid);
                }
            }
            else {
                grpname = gr->gr_name;
            }
        }
        else {
            if ((pw = getpwuid(r->server->server_uid)) == NULL) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
                             "getpwuid: invalid userid %ld",
                             (long) r->server->server_uid);
                return (pid);
            }
            execuser = ap_pstrdup(r->pool, pw->pw_name);

            if ((gr = getgrgid(r->server->server_gid)) == NULL) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
                             "getgrgid: invalid groupid %ld",
                             (long) r->server->server_gid);
                return (pid);
            }
            grpname = gr->gr_name;
        }

        if (shellcmd) {
            execle(SUEXEC_BIN, SUEXEC_BIN, execuser, grpname, argv0,
                   NULL, env);
        }

        else if ((!r->args) || (!r->args[0]) || strchr(r->args, '=')) {
            execle(SUEXEC_BIN, SUEXEC_BIN, execuser, grpname, argv0,
                   NULL, env);
        }

        else {
            execve(SUEXEC_BIN,
                   create_argv(r->pool, SUEXEC_BIN, execuser, grpname,
                               argv0, r->args),
                   env);
        }
    }
    else {
#endif
        if (shellcmd) {
            execle(SHELL_PATH, SHELL_PATH, "-c", argv0, NULL, env);
        }

        else if ((!r->args) || (!r->args[0]) || strchr(r->args, '=')) {
            execle(r->filename, argv0, NULL, env);
        }

        else {
            execve(r->filename,
                   create_argv(r->pool, NULL, NULL, NULL, argv0, r->args),
                   env);
        }
#if 0
    }
#endif
    return (pid);
#endif
}