/*
*******************************************************************************
*  Copyright (c) 1997 Martin Poole
*******************************************************************************
**
** WARNING !!  WARNING !! WARNING !! WARNING !! WARNING !! WARNING !!
**
** Any changes to be made to this file should first be checked with
** mplib1 source control for library integrity.
**
** mplib1 source control can be reached at  mplib1@quatermass.co.uk
** 
*
*  $Source: /home/cvs/cvsroot/onelan/onelan/src/mplib1/util/watch_run.c,v $
*  $Author: mpoole $
*  $Date: 2002/10/07 09:37:30 $
*  $Revision: 1.2 $
*
*******************************************************************************
*
* Change History
*
* $Log: watch_run.c,v $
* Revision 1.2  2002/10/07 09:37:30  mpoole
* Initial checkin of mplib1-3.1.0
*
* Revision 1.1  2002/10/07 09:37:09  mpoole
* Initial checkin of mplib1-3.1.0
*
*
*******************************************************************************
*/

#ident "$Header: /home/cvs/cvsroot/onelan/onelan/src/mplib1/util/watch_run.c,v 1.2 2002/10/07 09:37:30 mpoole Exp $"

/* ------------------------------------------------------------------
    Include files
   ------------------------------------------------------------------ */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <memory.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ipc.h>
#include <sys/mman.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>

#include <mplib1/dl_list.h>
#include <mplib1/cfg_file.h>
#include <mplib1/pid_check.h>
#include <mplib1/fprintfile.h>
#include <mplib1/fgetline.h>
#include <mplib1/bpo_queue.h>
#include <mplib1/build_argv.h>
#include <mplib1/daemon.h>

#include "watchdog.h"

/* ------------------------------------------------------------------
    structures / defines
   ------------------------------------------------------------------ */

static int watch_run_debug=0;

/* ------------------------------------------------------------------
    Code starts here
   ------------------------------------------------------------------ */

static void
set_env_variable( const char *name, const char *val )
{
    char *nep, obuf[500];
    if (name && *name && val && *val)
    {
	sprintf( obuf, "%s=%s", name, val );
	nep = strdup(obuf);
	putenv( nep );
    }
    return;
}

static void
load_env_file( const char *envname )
{
    char tbuf[255];
    FILE *fp;
    char *nep;

    if ( (fp=fopen(envname, "r" )) )
    {
        while (fgetline2( fp, tbuf, 255 ) ==0)
        {
            if (strchr( tbuf, '=' ))
            {
                nep = strdup(tbuf);
                putenv( nep );
            }
        }
        fclose(fp);
    }
    return;
}

static int
add_pid_track( struct program_hdr *pptr, int exp_time )
{
    struct pid_track *ptp;
    int rv=0;
    ptp = alloc_pid_track( pptr, exp_time );
    if (ptp)
    {
	rv=1;
    }
    return(rv);
}

static int
add_this_pid_track( struct program_hdr *pptr, pid_t the_pid )
{
    struct pid_track *ptp;
    int rv=0;
    ptp = alloc_pid_track( pptr, 0 );
    if (ptp)
    {
	/* Now update the status of this track */
	ptp->starting=0;
	ptp->dying = 0;
	ptp->the_pid = the_pid;
	ptp->track_by_pid=1;
	gen_pid_str( ptp->pid_str, the_pid );
	rv=1;
    }
    return(rv);
}

static int
is_dir( const char *dir_name )
{
    struct stat d_stat;
    int rv=0;
    if (stat(dir_name,&d_stat)==0)
    {
	rv = S_ISDIR(d_stat.st_mode);
    }
    return(rv);
}

int
start_this_program( int nbr_to_start,
		    struct program_hdr *pptr,
		    const char *env_name,
		    const char *out_name,
		    const char *err_name,
		    const char *run_dir,
		    int exp_time,
		    int track_by_pid )
{
    pid_t child_pid;
    int nbr_started=0;
    struct argv_track *argvtp;
    char *rdir;

    watch_run_debug = get_config_flag("WATCH_RUN_DEBUG");

    exp_time = get_default_int( exp_time, "START_HYSTERESIS", 15 );

    if (watch_run_debug)
    {
	fprintfile( stderr, "start_this_program: %s (%s %s)  %d copies\n",
		    pptr->prg_name, pptr->exe_name,
		    pptr->opt_name, nbr_to_start );
    }
    if (pptr->env_name && *pptr->env_name)
	env_name = pptr->env_name;
    if (pptr->out_name && *pptr->out_name)
	out_name = pptr->out_name;
    if (pptr->err_name && *pptr->err_name)
	err_name = pptr->err_name;

    if (exp_time<1)
	exp_time=2;
    argvtp = build_argv_track( NULL, pptr->exe_name, pptr->opt_name, NULL );
    if (argvtp)
    {
	while(nbr_to_start--)
	{
	    /* First we fork */
	    child_pid = fork();

	    if (child_pid == (pid_t)0)
	    {
		/* OK so set things up and exec */
		if (env_name && *env_name)
		    load_env_file( env_name );
		if (pptr->grp_name)
		    set_env_variable( "PROGRAM_GROUP", pptr->grp_name );
		if (pptr->prg_name)
		    set_env_variable( "PROGRAM_NAME", pptr->prg_name );
		restart_these_files( NULL, out_name, err_name );
		if (    pptr->run_dir
		    && *pptr->run_dir
		    && (rdir=eval_config_default(NULL,pptr->run_dir))
		    && is_dir(rdir)
		   )
		{
		    if (chdir(run_dir))
		    {
			fprintfile( stderr, "Unable to chdir %s<%d>\n", rdir, errno );
		    }
		}else
		if (   run_dir
		    && *run_dir
		    && is_dir(run_dir)
		   )
		{
		    if (chdir(run_dir))
		    {
			fprintfile( stderr, "Unable to chdir %s<%d>\n", run_dir, errno );
		    }
		}
		execvp( pptr->exe_name, argvtp->argv );
		fprintfile( stderr, "Unable to exec %s\n", pptr->prg_name );
		exit(1);
	    }else if (child_pid > (pid_t)0)
	    {
		/* Add a program_pid entry */
		nbr_started++;
		if (track_by_pid)
		    add_this_pid_track( pptr, child_pid );
		else
		    add_pid_track( pptr, exp_time );
	    }else
	    {
		fprintfile( stderr, "Unable to fork for %s\n", pptr->prg_name );
	    }
	};
	free_argv_track(argvtp);
    }
    return(nbr_started);
}

void
start_some_program( struct program_hdr *pptr, int copies )
{
    char *env_name,*out_name,*err_name,*run_dir;
    int stime;

    stime = pptr->startup;

    /* need to start some more */
    env_name = strdup( eval_config_default( "ENVIRONMENT",
					"$HOME/config/environment" ) );
    err_name = strdup( eval_config_default( "NEWSTDERR", "/dev/null" ));
    out_name = strdup( eval_config_default( "NEWSTDOUT", "/dev/null" ));
    run_dir = strdup( eval_config_default( "RUN_DIR", "." ));
    start_this_program( copies, pptr,
			env_name, out_name, err_name, run_dir,
			stime, pptr->track_by_pid );
    free( run_dir );
    free( out_name );
    free( err_name );
    free( env_name );
    return;
}

/* -- End of File -- */