[SOLVED] How to read serial with interrupt serial?

How to read serial with interrupt serial?

I'm trying to read NMEA message in Linux. But I can't get a completely message:

54.441,V,,,,,0.00,0.00,010720,,,N*42
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,020954.441,,,,,0,0,,,M,,M,,*43
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,1,1,00*79
$GLGSV,1,1,00*65
$GPGLL,,,,,020954.441,V,N*71
$GP

The first line and last line is the one message but it have been splited. I thing, It's cause by sleep 1 second. And It's not right at all. I think I should use interrupt serial.

My idea is when data in come, interrupt serial will run a function which read serial and handle it. After that, system will sleep until next message. I searched some material but It's doesn't help.

This is my new code and it's not working:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <fcntl.h>
#include <sys/signal.h>
#include <errno.h>
#include <termios.h>

void signal_handler_IO ();  

int fd;
int connected;
struct termios termAttr;
struct sigaction saio;

int main(int argc, char *argv[])
{
     fd = open("/dev/ttyUSB0", O_RDWR | O_NOCTTY | O_NDELAY);
     if (fd == -1)
     {
        perror("open_port: Unable to open port\n");
        exit(1);
     }
     saio.sa_handler = signal_handler_IO;
     saio.sa_flags = 0;
     saio.sa_restorer = NULL; 
     sigaction(SIGIO,&saio,NULL);

     fcntl(fd, F_SETFL, FNDELAY);
     fcntl(fd, F_SETOWN, getpid());
     fcntl(fd, F_SETFL,  O_ASYNC );

     tcgetattr(fd,&termAttr);       
     cfsetispeed(&termAttr,B9600);  
     cfsetospeed(&termAttr,B9600);  
     termAttr.c_cflag &= ~PARENB;   
     termAttr.c_cflag &= ~CSTOPB;   
     termAttr.c_cflag &= ~CSIZE;
     termAttr.c_cflag |= CS8;         
     termAttr.c_cflag |= (CLOCAL | CREAD); 
     termAttr.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); 
     termAttr.c_iflag &= ~(IXON | IXOFF | IXANY); 
     termAttr.c_oflag &= ~OPOST; 
     tcsetattr(fd,TCSANOW,&termAttr);
     printf("UART1 configured....\n");

     while(1){
         sleep(1);
     }
     close(fd);
     exit(0);   
          
}

void signal_handler_IO ()
{
    FILE *csv;
    char buff [1024];
    int n = read(fd, &buff, sizeof(buff));
    char * token = strtok(buff, ",");
    csv=fopen("csvfile.csv","w");
    while( token != NULL ) {
      fprintf(csv,"%s\n",token);
      token = strtok(NULL, ","); 
    }
    fclose(csv);
}

What should I do now ?

Solution

NMEA message are lines, ending with a '\n'.

Change read() to fgets() (open using fopen()) and read as a line into a string for later strtok() processing.