start-stop-daemon.c

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/* ==================================================================== 
 * The Kannel Software License, Version 1.0 
 * 
 * Copyright (c) 2001-2008 Kannel Group  
 * Copyright (c) 1998-2001 WapIT Ltd.   
 * 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. The end-user documentation included with the redistribution, 
 *    if any, must include the following acknowledgment: 
 *       "This product includes software developed by the 
 *        Kannel Group (http://www.kannel.org/)." 
 *    Alternately, this acknowledgment may appear in the software itself, 
 *    if and wherever such third-party acknowledgments normally appear. 
 * 
 * 4. The names "Kannel" and "Kannel Group" must not be used to 
 *    endorse or promote products derived from this software without 
 *    prior written permission. For written permission, please  
 *    contact org@kannel.org. 
 * 
 * 5. Products derived from this software may not be called "Kannel", 
 *    nor may "Kannel" appear in their name, without prior written 
 *    permission of the Kannel Group. 
 * 
 * THIS SOFTWARE IS PROVIDED ``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 KANNEL 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 Kannel Group.  For more information on  
 * the Kannel Group, please see <http://www.kannel.org/>. 
 * 
 * Portions of this software are based upon software originally written at  
 * WapIT Ltd., Helsinki, Finland for the Kannel project.  
 */ 

/* This utility was added to the Kannel source tree for the benefit of
 * those distributions that aren't Debian.  It is used by kannel-init.d
 * to start and stop the run_kannel_box daemon. 
 * It was copied from the dpkg 1.6.11 source tree on 21 March 2000.
 * If that was very long ago, refreshing the copy would be a good idea,
 * in case bugs were fixed.
 * Richard Braakman
 */

/*
 * A rewrite of the original Debian's start-stop-daemon Perl script
 * in C (faster - it is executed many times during system startup).
 *
 * Written by Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>,
 * public domain.  Based conceptually on start-stop-daemon.pl, by Ian
 * Jackson <ijackson@gnu.ai.mit.edu>.  May be used and distributed
 * freely for any purpose.  Changes by Christian Schwarz
 * <schwarz@monet.m.isar.de>, to make output conform to the Debian
 * Console Message Standard, also placed in public domain.  Minor
 * changes by Klee Dienes <klee@debian.org>, also placed in the Public
 * Domain.
 *
 * Changes by Ben Collins <bcollins@debian.org>, added --chuid, --background
 * and --make-pidfile options, placed in public domain aswell.
 */

#include "gw-config.h"

#if defined(linux)
#define OSLinux
#elif defined(__GNU__)
#define OSHURD
#elif defined(SunOS)
#elif defined(__CYGWIN__)
#elif defined(__FreeBSD__) || defined(__APPLE__)
#define FreeBSD
#else
#error Unknown architecture - cannot build start-stop-daemon
#endif

#ifdef HAVE_HURH_H
#include <hurd.h>
#endif
#ifdef HAVE_PS_H
#include <ps.h>
#endif

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <signal.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#if HAVE_GETOPT_H
#include <getopt.h>
#endif
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/termios.h>
#include <fcntl.h>

/*Solaris needs to be told how
to talk to it's proc filesystem*/
#define _STRUCTURED_PROC 1
#ifdef SunOS
#include <sys/procfs.h>
#endif


#ifdef HAVE_ERROR_H
#include <error.h>
#endif
#ifdef HURD_IHASH_H
#include <hurd/ihash.h>
#endif

static int testmode = 0;
static int quietmode = 0;
static int exitnodo = 1;
static int start = 0;
static int stop = 0;
static int background = 0;
static int mpidfile = 0;
static int signal_nr = 15;
static const char *signal_str = NULL;
static int user_id = -1;
static int runas_uid = -1;
static int runas_gid = -1;
static const char *userspec = NULL;
static char *changeuser = NULL;
static char *changegroup = NULL;
static char *changeroot = NULL;
static const char *cmdname = NULL;
static char *execname = NULL;
static char *startas = NULL;
static const char *pidfile = NULL;
static const char *progname = "";

static struct stat exec_stat;
#if defined(OSHURD)
static struct ps_context *context;
static struct proc_stat_list *procset;
#endif


struct pid_list {
    struct pid_list *next;
    int pid;
};

static struct pid_list *found = NULL;
static struct pid_list *killed = NULL;

static void *xmalloc(int size);
static void push(struct pid_list **list, int pid);
static void do_help(void);
static void parse_options(int argc, char * const *argv);
#if defined(OSLinux) || defined(OSHURD) || defined(SunOS) || defined(FreeBSD)
static int pid_is_user(int pid, int uid);
static int pid_is_cmd(int pid, const char *name);
#endif
static void check(int pid);
static void do_pidfile(const char *name);
static int do_stop(void);
#if defined(OSLinux)
static int pid_is_exec(int pid, const struct stat *esb);
#endif
#if defined(OSHURD)
static void do_psinit(void);
#endif


#ifdef __GNUC__
static void fatal(const char *format, ...)
    __attribute__((noreturn, format(printf, 1, 2)));
static void badusage(const char *msg)
    __attribute__((noreturn));
#else
static void fatal(const char *format, ...);
static void badusage(const char *msg);
#endif

static void
fatal(const char *format, ...)
{
    va_list arglist;

    fprintf(stderr, "%s: ", progname);
    va_start(arglist, format);
    vfprintf(stderr, format, arglist);
    va_end(arglist);
    putc('\n', stderr);
    exit(2);
}


static void *
xmalloc(int size)
{
    void *ptr;

    ptr = malloc(size);
    if (ptr)
        return ptr;
    fatal("malloc(%d) failed", size);
}


static void
push(struct pid_list **list, int pid)
{
    struct pid_list *p;

    p = xmalloc(sizeof(*p));
    p->next = *list;
    p->pid = pid;
    *list = p;
}


static void
do_help(void)
{

/*Print the help for systems that have getopt long*/

#ifndef SunOS     /*Solaris doesn't*/

    printf("\
start-stop-daemon for Debian GNU/Linux - small and fast C version written by\n\
Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>, public domain.\n"
GW_VERSION "\n\
\n\
Usage:\n\
  start-stop-daemon -S|--start options ... -- arguments ...\n\
  start-stop-daemon -K|--stop options ...\n\
  start-stop-daemon -H|--help\n\
  start-stop-daemon -V|--version\n\
\n\
Options (at least one of --exec|--pidfile|--user is required):\n\
  -x|--exec <executable>        program to start/check if it is running\n\
  -p|--pidfile <pid-file>       pid file to check\n\
  -c|--chuid <name|uid[:group|gid]>\n\
        change to this user/group before starting process\n\
  -u|--user <username>|<uid>    stop processes owned by this user\n\
  -n|--name <process-name>      stop processes with this name\n\
  -s|--signal <signal>          signal to send (default TERM)\n\
  -a|--startas <pathname>       program to start (default is <executable>)\n\
  -b|--background               force the process to detach\n\
  -m|--make-pidfile             create the pidfile before starting\n\
  -t|--test                     test mode, don't do anything\n\
  -o|--oknodo                   exit status 0 (not 1) if nothing done\n\
  -q|--quiet                    be more quiet\n\
  -v|--verbose                  be more verbose\n\
\n\
Exit status:  0 = done  1 = nothing done (=> 0 if --oknodo)  2 = trouble\n");

#else /* Deal with systems that don't have getopt long, like Solaris*/

    printf("\
start-stop-daemon for Debian GNU/Linux - small and fast C version written by\n\
Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>, public domain.\n"
GW_VERSION "\n\
\n\
Usage:\n\
  start-stop-daemon -S options ... -- arguments ...\n\
  start-stop-daemon -K options ...\n\
  start-stop-daemon -H\n\
  start-stop-daemon -V\n\
\n\
Options (at least one of --exec|--pidfile|--user is required):\n\
  -x <executable>               program to start/check if it is running\n\
  -p <pid-file>                 pid file to check\n\
  -c <name|uid[:group|gid]>     change to this user/group before starting process\n\
  -u <username>|<uid>           stop processes owned by this user\n\
  -n <process-name>             stop processes with this name\n\
  -s <signal>                   signal to send (default TERM)\n\
  -a <pathname>                 program to start (default is <executable>)\n\
  -b                            force the process to detach\n\
  -m                            create the pidfile before starting\n\
  -t                            test mode, don't do anything\n\
  -o                            exit status 0 (not 1) if nothing done\n\
  -q                            be more quiet\n\
  -v                            be more verbose\n\
\n\
Exit status:  0 = done  1 = nothing done (=> 0 if -o)  2 = trouble\n");
#endif   /*No more OS ( getopt ) specific stuff this function... */
}


static void
badusage(const char *msg)
{
    if (msg)
        fprintf(stderr, "%s: %s\n", progname, msg);

    #ifndef SunOS
    fprintf(stderr, "Try `%s --help' for more information.\n", progname);
    #else
    fprintf(stderr, "Try `%s -H' for more information.\n", progname);
    #endif

    exit(2);
}

struct sigpair {
    const char *name;
    int signal;
};

static const struct sigpair siglist[] = {
    { "ABRT", SIGABRT },
    { "ALRM", SIGALRM },
    { "FPE", SIGFPE },
    { "HUP", SIGHUP },
    { "ILL", SIGILL },
    { "INT", SIGINT },
    { "KILL", SIGKILL },
    { "PIPE", SIGPIPE },
    { "QUIT", SIGQUIT },
    { "SEGV", SIGSEGV },
    { "TERM", SIGTERM },
    { "USR1", SIGUSR1 },
    { "USR2", SIGUSR2 },
    { "CHLD", SIGCHLD },
    { "CONT", SIGCONT },
    { "STOP", SIGSTOP },
    { "TSTP", SIGTSTP },
    { "TTIN", SIGTTIN },
    { "TTOU", SIGTTOU }
};
static int sigcount = sizeof (siglist) / sizeof (siglist[0]);

static int parse_signal (const char *signal_str, int *signal_nr)
{
    int i;
    for (i = 0; i < sigcount; i++) {
        if (strcmp (signal_str, siglist[i].name) == 0) {
            *signal_nr = siglist[i].signal;
            return 0;
        }
    }
    return -1;
}

static void
parse_options(int argc, char * const *argv)
{

#if HAVE_GETOPT_LONG
    static struct option longopts[] = {
        { "help",     0, NULL, 'H'},
        { "stop",     0, NULL, 'K'},
        { "start",    0, NULL, 'S'},
        { "version",      0, NULL, 'V'},
        { "startas",      1, NULL, 'a'},
        { "name",     1, NULL, 'n'},
        { "oknodo",   0, NULL, 'o'},
        { "pidfile",      1, NULL, 'p'},
        { "quiet",    0, NULL, 'q'},
        { "signal",   1, NULL, 's'},
        { "test",     0, NULL, 't'},
        { "user",     1, NULL, 'u'},
        { "chroot",   1, NULL, 'r'},
        { "verbose",      0, NULL, 'v'},
        { "exec",     1, NULL, 'x'},
        { "chuid",    1, NULL, 'c'},
        { "background",   0, NULL, 'b'},
        { "make-pidfile", 0, NULL, 'm'},
        { NULL,     0, NULL, 0}
    };
#endif
    int c;

    for (;;) {
#if HAVE_GETOPT_LONG
        c = getopt_long(argc, argv, "HKSVa:n:op:qr:s:tu:vx:c:bm",
                longopts, (int *) 0);
#else
        c = getopt(argc, argv, "HKSVa:n:op:qr:s:tu:vx:c:bm");
#endif
        if (c == -1)
            break;
        switch (c) {
        case 'H':  /* --help */
            do_help();
            exit(0);
        case 'K':  /* --stop */
            stop = 1;
            break;
        case 'S':  /* --start */
            start = 1;
            break;
        case 'V':  /* --version */
            printf("start-stop-daemon " GW_VERSION "\n");
            exit(0);
        case 'a':  /* --startas <pathname> */
            startas = optarg;
            break;
        case 'n':  /* --name <process-name> */
            cmdname = optarg;
            break;
        case 'o':  /* --oknodo */
            exitnodo = 0;
            break;
        case 'p':  /* --pidfile <pid-file> */
            pidfile = optarg;
            break;
        case 'q':  /* --quiet */
            quietmode = 1;
            break;
        case 's':  /* --signal <signal> */
            signal_str = optarg;
            break;
        case 't':  /* --test */
            testmode = 1;
            break;
        case 'u':  /* --user <username>|<uid> */
            userspec = optarg;
            break;
        case 'v':  /* --verbose */
            quietmode = -1;
            break;
        case 'x':  /* --exec <executable> */
            execname = optarg;
            break;
        case 'c':  /* --chuid <username>|<uid> */
            /* we copy the string just in case we need the
             * argument later. */
            changeuser = strdup(optarg);
            changeuser = strtok(changeuser, ":");
            changegroup = strtok(NULL, ":");
            break;
        case 'r':  /* --chroot /new/root */
            changeroot = optarg;
            break;
        case 'b':  /* --background */
            background = 1;
            break;
        case 'm':  /* --make-pidfile */
            mpidfile = 1;
            break;
        default:
            badusage(NULL);  /* message printed by getopt */
        }
    }

    if (signal_str != NULL) {
        if (sscanf (signal_str, "%d", &signal_nr) != 1) {
            if (parse_signal (signal_str, &signal_nr) != 0) {
                badusage ("--signal takes a numeric argument or name of signal (KILL, INTR, ...)");
            }
        }   
    }

    if (start == stop)
        #ifndef SunOS
        badusage("need one of --start or --stop");
        #else
        badusage("need one of -S (start) or -K (stop)");
        #endif

    if (!execname && !pidfile && !userspec)
        badusage("need at least one of --exec, --pidfile or --user");

    if (!startas)
        startas = execname;

    if (start && !startas)
        badusage("--start needs --exec or --startas");

    if (mpidfile && pidfile == NULL)
        badusage("--make-pidfile is only relevant with --pidfile");

    if (background && !start)
        badusage("--background is only relevant with --start");

}

#if defined(OSLinux)
static int
pid_is_exec(int pid, const struct stat *esb)
{
    struct stat sb;
    char buf[32];

    sprintf(buf, "/proc/%d/exe", pid);
    if (stat(buf, &sb) != 0)
        return 0;
    return (sb.st_dev == esb->st_dev && sb.st_ino == esb->st_ino);
}


static int
pid_is_user(int pid, int uid)
{
    struct stat sb;
    char buf[32];

    sprintf(buf, "/proc/%d", pid);
    if (stat(buf, &sb) != 0)
        return 0;
    return ((int) sb.st_uid == uid);
}


static int
pid_is_cmd(int pid, const char *name)
{
    char buf[32];
    FILE *f;
    int c;

    sprintf(buf, "/proc/%d/stat", pid);
    f = fopen(buf, "r");
    if (!f)
        return 0;
    while ((c = getc(f)) != EOF && c != '(')
        ;
    if (c != '(') {
        fclose(f);
        return 0;
    }
    /* this hopefully handles command names containing ')' */
    while ((c = getc(f)) != EOF && c == *name)
        name++;
    fclose(f);
    return (c == ')' && *name == '\0');
}
#endif /* OSLinux */

#if defined(OSHURD)
static int
pid_is_user(int pid, int uid)
{
   struct stat sb;
   char buf[32];
   struct proc_stat *pstat;

   sprintf(buf, "/proc/%d", pid);
   if (stat(buf, &sb) != 0)
       return 0;
   return (sb.st_uid == uid);
   pstat = proc_stat_list_pid_proc_stat (procset, pid);
   if (pstat == NULL)
       fatal ("Error getting process information: NULL proc_stat struct");
   proc_stat_set_flags (pstat, PSTAT_PID | PSTAT_OWNER_UID);
   return (pstat->owner_uid == uid);
}

static int
pid_is_cmd(int pid, const char *name)
{
   struct proc_stat *pstat;
   pstat = proc_stat_list_pid_proc_stat (procset, pid);
   if (pstat == NULL)
       fatal ("Error getting process information: NULL proc_stat struct");
   proc_stat_set_flags (pstat, PSTAT_PID | PSTAT_ARGS);
   return (!strcmp (name, pstat->args));
}
#endif /* OSHURD */

#if defined(SunOS)
/*
Lots of lovely system dependant functions for Solaris.  I used to like the
idea of proc, but now I'm not so sure.  It feels to much like a kludge.
*/

/*
pid_is_user, takes the pid and a uid, normally ours, but can be someone
elses, to allow you to identify the process' owner. returns zero on success,
and either true or the uid of the owner on failure (this may be undefined,
or I may be misremembering.
*/
static int
pid_is_user(int pid, int uid)
{
   struct stat sb;
   char buf[32];

   sprintf(buf, "/proc/%d", pid);
   if (stat(buf, &sb) != 0)
      return 0; /*I can stat it so it seems to be mine...*/
   return ((int) sb.st_uid == uid);
}

/*
pid_is_cmd, takes a pid, and a string representing the process' (supposed)
name.  Compares the process' supposed name with the name reported by the
system.  Returns zero on failure, and nonzero on success.
*/
static int
pid_is_cmd(int pid, const char *name)
{
   char buf[32];
   FILE *f;
   psinfo_t pid_info;

   sprintf(buf, "/proc/%d/psinfo", pid);
   f = fopen(buf, "r");
   if (!f)
      return 0;
   fread(&pid_info,sizeof(psinfo_t),1,f);
   return (!strcmp(name,pid_info.pr_fname));
}
#endif /*SunOS*/

#ifdef FreeBSD
static int pid_is_user(int pid, int uid)
{
 struct stat sb;
 char buf[32];

 sprintf(buf, "/proc/%d", pid);
 if (stat(buf, &sb) != 0)
  return 0;
 return ((int) sb.st_uid == uid);
}

static int
pid_is_cmd(int pid, const char *name)
{
    char buf[32];
    FILE *f;
    int c;

    sprintf(buf, "/proc/%d/stat", pid);
    f = fopen(buf, "r");
    if (!f)
        return 0;
    while ((c = getc(f)) != EOF && c != '(')
        ;
    if (c != '(') {
        fclose(f);
        return 0;
    }
    /* this hopefully handles command names containing ')' */
    while ((c = getc(f)) != EOF && c == *name)
        name++;
    fclose(f);
    return (c == ')' && *name == '\0');
}
#endif /*FreeBSD*/

static void
check(int pid)
{
#if defined(OSLinux)
    if (execname && !pid_is_exec(pid, &exec_stat))
        return;
#elif defined(OSHURD)
    /* I will try this to see if it works */
    if (execname && !pid_is_cmd(pid, execname))
        return;
#endif
    if (userspec && !pid_is_user(pid, user_id))
        return;
    if (cmdname && !pid_is_cmd(pid, cmdname))
        return;
    push(&found, pid);
}


static void
do_pidfile(const char *name)
{
    FILE *f;
    int pid;

    f = fopen(name, "r");
    if (f) {
        if (fscanf(f, "%d", &pid) == 1)
            check(pid);
        fclose(f);
    }
}

/* WTA: this  needs to be an autoconf check for /proc/pid existance.
 */
#if defined(OSLinux) || defined (SunOS) || defined(FreeBSD)
static void
do_procinit(void)
{
    DIR *procdir;
    struct dirent *entry;
    int foundany, pid;

    procdir = opendir("/proc");
    if (!procdir)
        fatal("opendir /proc: %s", strerror(errno));

    foundany = 0;
    while ((entry = readdir(procdir)) != NULL) {
        if (sscanf(entry->d_name, "%d", &pid) != 1)
            continue;
        foundany++;
        check(pid);
    }
    closedir(procdir);
    if (!foundany)
        fatal("nothing in /proc - not mounted?");
}
#endif /* OSLinux */


#if defined(OSHURD)
error_t
check_all (void *ptr)
{
   struct proc_stat *pstat = ptr;

   check (pstat->pid);
   return (0);
}

static void
do_psinit(void)
   error_t err;

   err = ps_context_create (getproc (), &context);
   if (err)
       error (1, err, "ps_context_create");

   err = proc_stat_list_create (context, &procset);
   if (err)
       error (1, err, "proc_stat_list_create");

   err = proc_stat_list_add_all (procset, 0, 0);
   if (err)
       error (1, err, "proc_stat_list_add_all");

   /* Check all pids */
   ihash_iterate (context->procs, check_all);
}
#endif /* OSHURD */

/* return 1 on failure */
static int
do_stop(void)
{
    char what[1024];
    struct pid_list *p;
    int retval = 0;

    if (cmdname)
        strcpy(what, cmdname);
    else if (execname)
        strcpy(what, execname);
    else if (pidfile)
        sprintf(what, "process in pidfile `%s'", pidfile);
    else if (userspec)
        sprintf(what, "process(es) owned by `%s'", userspec);
    else
        fatal("internal error, please report");

    if (!found) {
        if (quietmode <= 0)
            printf("No %s found running; none killed.\n", what);
        exit(exitnodo);
    }
    for (p = found; p; p = p->next) {
        if (testmode)
            printf("Would send signal %d to %d.\n",
                   signal_nr, p->pid);
        else if (kill(p->pid, signal_nr) == 0)
            push(&killed, p->pid);
        else {
            printf("%s: warning: failed to kill %d: %s\n",
                   progname, p->pid, strerror(errno));
            retval += exitnodo;
        }
    }
    if (quietmode < 0 && killed) {
        printf("Stopped %s (pid", what);
        for (p = killed; p; p = p->next)
            printf(" %d", p->pid);
        printf(").\n");
    }
    return retval;
}


int
main(int argc, char **argv)
{
    progname = argv[0];

    parse_options(argc, argv);
    argc -= optind;
    argv += optind;

    if (execname && stat(execname, &exec_stat))
        fatal("stat %s: %s", execname, strerror(errno));

    if (userspec && sscanf(userspec, "%d", &user_id) != 1) {
        struct passwd *pw;

        pw = getpwnam(userspec);
        if (!pw)
            fatal("user `%s' not found\n", userspec);

        user_id = pw->pw_uid;
    }
    
    if (changegroup && sscanf(changegroup, "%d", &runas_gid) != 1) {
        struct group *gr = getgrnam(changegroup);
        if (!gr)
            fatal("group `%s' not found\n", changegroup);
        runas_gid = gr->gr_gid;
    }
    if (changeuser && sscanf(changeuser, "%d", &runas_uid) != 1) {
        struct passwd *pw = getpwnam(changeuser);
        if (!pw)
            fatal("user `%s' not found\n", changeuser);
        runas_uid = pw->pw_uid;
        if (changegroup == NULL) { /* pass the default group of this user */
            changegroup = ""; /* just empty */
            runas_gid = pw->pw_gid;
        }
    }

    if (pidfile)
        do_pidfile(pidfile);
    else
        do_procinit();

    if (stop) {
        int i = do_stop();
        if (i) {
            if (quietmode <= 0)
                printf("%d pids were not killed\n", i);
            exit(1);
        }
        exit(0);
    }

    if (found) {
        if (quietmode <= 0)
            printf("%s already running.\n", execname);
        exit(exitnodo);
    }
    if (testmode) {
        printf("Would start %s ", startas);
        while (argc-- > 0)
            printf("%s ", *argv++);
        if (changeuser != NULL) {
            printf(" (as user %s[%d]", changeuser, runas_uid);
            if (changegroup != NULL)
                printf(", and group %s[%d])", changegroup, runas_gid);
            else
                printf(")");
        }
        if (changeroot != NULL)
            printf(" in directory %s", changeroot);
        printf(".\n");
        exit(0);
    }
    if (quietmode < 0)
        printf("Starting %s...\n", startas);
    *--argv = startas;
    if (changeroot != NULL) {
        if (chdir(changeroot) < 0)
            fatal("Unable to chdir() to %s", changeroot);
        if (chroot(changeroot) < 0)
            fatal("Unable to chroot() to %s", changeroot);
    }
    if (changeuser != NULL) {
        if (setgid(runas_gid))
            fatal("Unable to set gid to %d", runas_gid);
        if (initgroups(changeuser, runas_gid))
            fatal("Unable to set initgroups() with gid %d", runas_gid);
        if (setuid(runas_uid))
            fatal("Unable to set uid to %s", changeuser);
    }
    
    if (background) { /* ok, we need to detach this process */
        int i, fd;
        if (quietmode < 0)
            printf("Detatching to start %s...", startas);
        i = fork();
        if (i<0) {
            fatal("Unable to fork.\n");
        }
        if (i) { /* parent */
            if (quietmode < 0)
                printf("done.\n");
            exit(0);
        }
         /* child continues here */
         /* now close all extra fds */
        for (i=getdtablesize()-1; i>=0; --i) close(i);
         /* change tty */
        fd = open("/dev/tty", O_RDWR);
        ioctl(fd, TIOCNOTTY, 0);
        close(fd);
        chdir("/");
        umask(022); /* set a default for dumb programs */
#ifndef FreeBSD
        setpgrp();  /* set the process group */
#else
        setpgrp(0, runas_gid);  /* set the process group */
#endif
        fd=open("/dev/null", O_RDWR); /* stdin */
        dup(fd); /* stdout */
        dup(fd); /* stderr */
    }
    if (mpidfile && pidfile != NULL) { /* user wants _us_ to make the pidfile :) */
        FILE *pidf = fopen(pidfile, "w");
        pid_t pidt = getpid();
        if (pidf == NULL)
            fatal("Unable to open pidfile `%s' for writing: %s", pidfile,
                strerror(errno));
        fprintf(pidf, "%d\n", (int)pidt);
        fclose(pidf);
    }
    execv(startas, argv);
    fatal("Unable to start %s: %s", startas, strerror(errno));
}

See file LICENSE for details about the license agreement for using, modifying, copying or deriving work from this software.