bluetoothctl demo

//client.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/socket.h>
#include <bluetooth/bluetooth.h>
#include <bluetooth/rfcomm.h>

int main( int argc , char **argv)
{
   struct sockaddr_rc addr={0};
   int s,status;
   char buf[1024];
   char dst[] = "58:88:97:4F:2C:41";
   time_t t;

   // a l l o c a t e a s oc k e t
   s=socket(PF_BLUETOOTH,SOCK_STREAM,BTPROTO_RFCOMM);
   if(s<0) {
       perror("create socket error");
       exit(1);
   }

   // s e t the conne c t ion parameter s (who to connect to )
   addr.rc_family=AF_BLUETOOTH;
   addr.rc_channel=(uint8_t)1;
   str2ba(dst,&addr.rc_bdaddr);
   // connect to s e r v e r
   printf("connectting...\n");
   status=connect(s,(struct sockaddr *)&addr,sizeof(addr));

   // send a message
   if(status==0) {
     printf("scuess!\n");

     do{
        gets(buf);
        time(&t);
        sprintf(buf, "{\"ssid\":\"%s\", \"psw\":\"%s\", \"timestamp\":%ld}","360ND", "00000000", t);
   //   sprintf(buf, "{\"ssid\":\"%s\", \"psw\":\"%s\", \"timestamp\":%ld}","SEC", "sec12345", t);
        printf("[%s]\n", buf);
        status=write(s,buf,strlen(buf));
        if(status<0) perror("uh oh");
     }while(strcmp(buf,"goodbye")!=0);
   }
   else {
     printf("Failed!\n");
   }

   close(s);
   return 0;
}