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irgenwie bekomme ich das select nicht so ganz hin...es wird immer auf die fifo gewartet. wenn da mal was kam, wird auch die serielle ausgelesen und beides geht gleichzeitig. aber wie kann man dieses erste senden vermeiden?
ich habe auch schon mit timeout probiert, aber auch ohne erfolg...das nonblocked-flag scheint zu funktionieren, aber es ist wahrscheinlich besser über select, oder?
/*
serial.c - serielle Schnittstelle
*/
//gcc -Wall serial.c -o serial
# include <stdio.h>
# include <unistd.h>
# include <fcntl.h>
# include <termios.h>
# include <errno.h>
//fifo
#include <sys/stat.h>
//#include <linux/stat.h>
//# define TERM_DEVICE "/dev/ttyS0" /* = COM1 */
//# define TERM_DEVICE "/dev/ttyACM0"
# define TERM_DEVICE "/dev/arduinoUNO"
//# define TERM_SPEED B19200 /* Bit/Sek */
# define TERM_SPEED B9600 /* Bit/Sek */
#define FIFO_FILE "/tmp/arduinoUNO"
#define true 1;
#define false 0;
/*
int fileexists(const char *file)
{
FILE *fp = fopen("file","r");
if( fp )
{
fclose(fp);
return true;
}else return false;
}*/
int fileexists(const char *file)
{
if (access(file, F_OK) == 0)
{
return true;
}else return false;
}
int main()
{
//vars for serial access
int fd_serial;
ssize_t length_serial,length_fifo;
char buffer_serial[16];
//vars for fifo
//FILE *fp;
int fd_fifo;
char buffer_fifo[80];
//for select (input switch)
fd_set input_fdset;
/* Create the FIFO if it does not exist */
if (!fileexists(FIFO_FILE))
{
umask(0);
mknod(FIFO_FILE, S_IFIFO|0666, 0);
}
struct termios term_attr;
if ((fd_serial = open(TERM_DEVICE, O_RDWR /*| O_NONBLOCK*/)) == -1)
{
perror("terminal: Can't open device " TERM_DEVICE);
return(1);
}
/* RS232 konfigurieren */
if (tcgetattr(fd_serial, &term_attr) != 0)
{
perror("terminal: tcgetattr() failed");
return(1);
}
term_attr.c_cflag = TERM_SPEED | CS8 | CRTSCTS | CLOCAL | CREAD;
term_attr.c_iflag = 0;
term_attr.c_oflag = OPOST;// | ONLCR;
term_attr.c_lflag = 0;
if (tcsetattr(fd_serial, TCSAFLUSH, &term_attr) != 0)
perror("terminal: tcsetattr() failed");
//open fifo
if((fd_fifo=open(FIFO_FILE,O_RDONLY /*| O_NONBLOCK*/))==(-1))
{
perror("Failure 'open pipe'");
}
int max;
if (fd_serial>fd_fifo) max=fd_serial;else max=fd_fifo;
//timeout für select
struct timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 500;
while (1)
{
FD_ZERO(&input_fdset);
FD_SET(fd_serial, &input_fdset);
FD_SET(fd_fifo, &input_fdset);
if (select(max+1, &input_fdset, NULL, NULL, &tv) == -1)
perror("terminal: select() failed");
if (!fileexists(TERM_DEVICE))
{
perror("<Symlink removed!!!>");
break;
}
int res_serial;
if (FD_ISSET(fd_serial, &input_fdset))
{
errno=0;
res_serial=(length_serial = read(fd_serial, buffer_serial, 16));
printf("[SERIAL] res: %d, length:%d, errno: %d\n",res_serial,length_serial,errno);
if (errno!=0) perror("[SERIAL error]");
}
int res_fifo;
if (FD_ISSET(fd_fifo, &input_fdset))
{
errno=0;
res_fifo=(length_fifo = read(fd_fifo, buffer_fifo, 80));
printf("[FIFO] res: %d, length:%d, errno: %d\n",res_fifo,length_fifo,errno);
if (errno!=0) perror("[PIPE error]");
}
if (res_serial>0)
{
buffer_serial[length_serial]='\0';
printf("[SERIAL] Received string: %s\n",buffer_serial);
}
if (res_fifo>0)
{
buffer_fifo[length_fifo]='\0';
printf("[PIPE] Received string: %s\n", buffer_fifo);
write(fd_serial, buffer_fifo, length_fifo); //write data from fifo to serial fd
}
sleep(1);//sleep for 1 second
}
printf("Aborted.\n");
//clean up
close(fd_fifo);
close(fd_serial);
remove(FIFO_FILE);
return(0);
}
