[SOLVED] Send more than one SMS at the same time with SIMCom Sim 300

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <termios.h>
#include <unistd.h>

#define STANDARD_BAUDRATE	B115200
#define MODEM_TTY "/dev/ttyS0"

static int open_port(void)
{
	int fd;
	fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY);
	if (fd == -1)
	{
		perror("open_port: Unable to open /dev/ttyS0 - ");
	}
	else
		fcntl(fd, F_SETFL, 0);

	return (fd);
}

static int sendModemChars(int fd, char *phone, char *msg)
{
	char buffer[255], *bufptr, foo[255];
	int  nbytes, msgLen;
	const char byte = 26;

	memset(buffer, 0x00, sizeof(buffer));
	memset(foo, 0x00, sizeof(foo));
	msgLen = strlen(msg);

	if (write(fd, "AT\r", 3) < 3)
	{
		printf("command AT failed!\n");
		return -1;
	}
	/* ler os caracteres retornado pelo MODEM */
	bufptr = buffer;
	while ( ( nbytes = read( fd, bufptr, (255 - 1) ) ) > 0 )
		bufptr += nbytes;

	*bufptr = '\0';
	nbytes = strlen(buffer);
	printf("command: %s\n", buffer);
	if (strncmp(&buffer[nbytes-4], "OK", 2) != 0)
	{
		printf("MODEM NOT_OK!!");
		return (-1);
	}

	printf("MODEM OK!!\n");
	sprintf(foo, "AT+CMGS=\"%s\"\r", phone);
	/* enviar comando para SMS do mondem */
	if (write(fd, foo, 25) < 25)
	{
		printf("comando AT+CMGS=\"%s\" falied!\n", phone);
		return -1;
	}
	memset(buffer, 0x00, sizeof(buffer));
	bufptr = buffer;
	while ( ( nbytes = read( fd, bufptr, (255 - 1) ) ) > 0 )
		bufptr += nbytes;

	*bufptr = '\0';
	nbytes = strlen(buffer);
	if (strncmp(&buffer[nbytes+5], ">", 1) == 0)
	{
		memset(foo, 0x00, sizeof(foo));
		sprintf(foo, "%s%c", msg, byte);
		if (write(fd, foo, (msgLen+1)) < (msgLen+1))
		{
			printf("msg Buffer failed.\n");
			return -1;
		}
		while ( ( nbytes = read( fd, bufptr, (255 - 1) ) ) > 0 ) /*just read*/

		sleep(2);
		memset(buffer, 0x00, sizeof(buffer));
		bufptr = buffer;
		while ( ( nbytes = read( fd, bufptr, (255 - 1) ) ) > 0 )
			bufptr += nbytes;

		*bufptr = '\0';
		nbytes = strlen(buffer);
		if (strncmp(&buffer[nbytes-4], "OK", 2) == 0)
		{
			printf("%s\n", buffer);
			return (0);
		}
		else return (-1);
	}
	return (-1);
}

int main( int argc, char *argv[] )
{
	int fd, ret;
	struct termios options;
	char phone[12+1], msg[160+1];

	memset(phone, 0x00, sizeof(phone));
	memset(msg, 0x00, sizeof(msg));
	memcpy(msg, "TEST SMS", 8);
	if(argc < 2 || argc > 2)
	{
		printf("Oops.. phone number??\n");
		exit(EXIT_FAILURE);
	}
	memcpy(phone, argv[1], strlen(argv[1]));
	fd = open_port();
	if ( fd < 0 )
	{
		perror(MODEM_TTY);
		exit(-1);
	}

	/* get the current options */
	tcgetattr(fd, &options);

	/* set raw input, 1 second timeout */
	options.c_cflag     |= ( CLOCAL | CREAD );
	options.c_lflag     &= ~(ICANON | ECHO | ECHOE | ISIG);
	options.c_oflag     &= ~OPOST;
	options.c_cc[VMIN]  = 0;
	options.c_cc[VTIME] = 10;

	/* set the options */
	tcsetattr(fd, TCSANOW, &options);

	ret = sendModemChars(fd, phone, msg);
	if ( ret == -1 )
		printf("modem NOK!!\n");

	close(fd);
	return 0;
}