1) 讀取程序執行時檔案，檔案內為程序Pid號
 2) 讀取程序號，呼叫系統呼叫kill,給程序發SIGTERM 訊號。


程式碼：
static int kill_spider_backgroud()
{
char path[MAX_PATH];
FILE *f;
int pid = 0; /* pid number from pid file */

/* set global dirs */

spd_snprintf(path, sizeof(path),"%s/%s", spd_global_dirs_PID_DIR, pfile);

if((f = fopen(path, "r")) == 0) {
fprintf(stderr, "Can't open pid file %s", path);
return -1;
}
if(fscanf(f, "d", &pid)!= 1) {
spd_log(LOG_ERROR, "unenble to get pid !\n");
}

/* send signal SIGTERM to kill */
if(pid > 0) {
spd_log(LOG_DEBUG, "Killing  %d\n", pid);
kill(pid, SIGTERM);
}

fclose(f);

return 0;
}