프로세스 종료 함수 wait() 에 대해서 질문이 있습니다. 전에 질문 내용을 보강 했습니다.^^;

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <signal.h>
#include <errno.h>
#include <time.h>
#include <pthread.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/msg.h>
 
#if 0
#  include <sqlite3.h>
#  define RESOLV_CONF           "/etc/resolv.conf"
#else
#  define RESOLV_CONF           "/tmp/resolv.conf"
#  define DEFAULT_SERVERIP_M    "0.0.0.0"
#  define DEFAULT_SERVERPORT_M  "0"
#  define DEFAULT_SERVERIP_S    "0.0.0.0"
#  define DEFAULT_SERVERPORT_S  "0"
 
#  define sqlite3               void
#  define SqliteDBOpen(x)       (void*)(NULL)
#  define SqliteDBDelete(x)     do {} while (0)
#  define SqliteDBInsert(x,y,z) do {} while (0)
#  define SqliteDBClose(x)      do {} while (0)
 
#  define ConnectFlowFileSave() do {} while (0)
#  define Process_exec(a,b,c,d,e) do {} while (0)
#  define ProcessIDFileSave()   do {} while (0)
struct config_file {
};
static struct ShmConfig {
        char ServerIp_M[64];
        char ServerPort_M[64];
        char ServerIp_S[64];
        char ServerPort_S[64];
        char LocalDns1[64];
        char LocalDns2[64];
        int Status;
} ShmConfig;
static struct ShmConfig *_ShmConfigPtr = &ShmConfig;
#endif
 
int ProcessWait( void )
{
        sqlite3  *WritDB = 0;
        FILE     *wfp;
 
        int      stat, n;
 
        struct config_file *_sptr;
        char   sptrbuf[sizeof( struct config_file )];
 
        _sptr = (struct config_file *)sptrbuf;
         memset( &sptrbuf[0], 0, sizeof( struct config_file ) );
 
        stat = -1;
        n = wait( &stat );
#ifdef DEBUG
        fprintf( stdout, "CO>> %d wait = (child stat=%d)\n", n, stat );
#endif
        if( n < 0 ) {
                if( errno == ECHILD ) { return 1; }
                else if( errno == EINTR ) { return 2; }
        }
        else if( n > 0 ) {
                if( stat == 7680 ) { //Process Fail
                        sleep( 4 );
                        WritDB = SqliteDBOpen( WritDB );
                        SqliteDBDelete( WritDB );
                        strcpy( &_ShmConfigPtr->ServerIp_M[0],   DEFAULT_SERVERIP_M );
                        strcpy( &_ShmConfigPtr->ServerIp_S[0],   DEFAULT_SERVERIP_S );
                        strcpy( &_ShmConfigPtr->ServerPort_M[0], DEFAULT_SERVERPORT_M );
                        strcpy( &_ShmConfigPtr->ServerPort_S[0], DEFAULT_SERVERPORT_S );
                        SqliteDBInsert( WritDB, _sptr, 2 ); SqliteDBClose( WritDB ); ConnectFlowFileSave();
                        Process_exec( RES_TCP_PROC, MSGQ_KEY01, NULL, SHM_KEY00, 3 );
                        ProcessIDFileSave();
                }
                else if( stat == 10240 || stat == 10496 || stat == 5120 ) {
                        sleep( 4 );
                        Process_exec( RES_TCP_PROC, MSGQ_KEY01, NULL, SHM_KEY00, 3 );
                        ProcessIDFileSave();
                }
                else if( stat == 10752 ) {
                        if( _ShmConfigPtr->Status == 1 ) {
                                sleep( 1 ); Process_exec( NULL, NULL, NULL, NULL, 21 );
                                sleep( 1 ); Process_exec( NULL, NULL, NULL, NULL, 23 );
                                sleep( 1 ); Process_exec( RES_TCP_PROC, MSGQ_KEY01, NULL,   SHM_KEY00, 3 );
                                ProcessIDFileSave();
                        }
                        else if( _ShmConfigPtr->Status == 2 ) {
                                sleep( 1 ); Process_exec( NULL, NULL, NULL, NULL, 24 );
                                sleep( 1 ); Process_exec( NULL, NULL, NULL, NULL, 22 );
                                sleep( 1 ); wfp = fopen( RESOLV_CONF, "w" );
                                fprintf( wfp, "nameserver %s\n", _ShmConfigPtr->LocalDns1 );
                                fprintf( wfp, "nameserver %s\n", _ShmConfigPtr->LocalDns2 );
                                fclose( wfp );
                                sleep( 1 ); Process_exec( NULL, NULL, NULL, NULL, 23 );
                                sleep( 1 ); Process_exec( RES_TCP_PROC, MSGQ_KEY01, NULL,   SHM_KEY00, 3 );
                                ProcessIDFileSave();
                        }
                        else if( _ShmConfigPtr->Status == 3 ) {
                                sleep( 4 );
                                Process_exec( RES_COM_PROC, MSGQ_KEY01, NULL,   SHM_KEY00, 4 );
                                ProcessIDFileSave();
                        }
                }
                return 2;
        }
        return 0;
}
 
int main()
{
        int rtn;
 
        while( 1 ){
                rtn = ProcessWait();
                if( rtn == 1 ) { break; }
                if( rtn == 2 ) { continue; }
        }
        return 0;
}