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| OS:linux 2.4.26
sometimes, possible after noise in line, I receive situation when
select() on port return then there are data available for read but
following read() return 0 bytes.
according to man tcsetattr and analogue with socket I understand this
situation as EOF.
All following pair select()/read() return same situation regardless
from data in port.
serial port open/tune via code:
<code>
port->fd =3D open(devfile, O_RDWR | O_NOCTTY);
if (port->fd =3D=3D -1) {syslog(LOG_ERR,"watcher_open_port():error
opening '%s': %m", devfile); free(port);return NULL; }
if (tcgetattr(port->fd, &ti) < 0)
{ syslog(LOG_ERR, "%s(%s):error getting terminal line modes:
%m",__func__, devfile); close(port->fd);free(port); return
NULL; }
cfmakeraw(&ti);
cfsetispeed(&ti, WATCHER_PORT_SPEED);
cfsetospeed(&ti, WATCHER_PORT_SPEED);
//c_iflag &=3D
~(IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNC
R|ICRNL|IXON);
ti.c_iflag |=3D IGNBRK;//??? =D0=B2=D0=BE=D0=B7=D0=BC=D0=BE=D0=B6=D0=
BD=
=D0=BE =D0=B8=D0=BC=D0=B5=D0=B5=D1=82 =D1=81=D0=BC=D1=8B=D1=81=D0=BB
=D0=BE=D1=81=D1=82=D0=B0=D0=B2=D0=B8=D1=
82=D1=8C =D1=8D=D1=82=D0=BE=D1=82 =
=D1=84=D0=BB=D0=B0=D0=B3 =D1=81=D0=BD=D1=8F=D1=82=D1=8B=D0=BC =D0=B0 =D0=B2=
=D0=BC=D0=B5=D1=81=D1=82=D0=BE
=D0=BD=D0=B5=D0=B3=D0=BE =D0=BF=D0=BE=D0=B4=D0=BD=D1=8F=D1=82=D1=
8C BRKINT?=
??
ti.c_iflag |=3D IGNPAR;//Ignore framing errors and parity errors.
ti.c_iflag &=3D ~(INPCK | PARMRK);
ti.c_iflag &=3D ~(IXOFF | IXON | IXANY); /* disable start/stop i/o
flow control*/
//c_oflag &=3D ~OPOST;
ti.c_cflag &=3D ~(PARENB | PARODD); /* no parity */
ti.c_cflag &=3D ~CSTOPB; /* 1 stop bit */
ti.c_cflag &=3D ~CRTSCTS; /* no i/o rts/cts flow control
*/
ti.c_cflag |=3D CLOCAL;
ti.c_cflag |=3D HUPCL;
ti.c_cflag |=3D CREAD;
//c_lflag &=3D ~(ECHO|ECHONL|ICANON|ISIG|IEXTEN);
//Disable flushing the input and output queues when
generating the SIGINT, SIGQUIT and SIGSUSP signals.
//ti.c_lflag &=3D ~(NOFLSH);//???=D0=B2=D0=BE=D0=B7=D0=BC=D0=BE=D0=
=B6=D0=BD=D0=BE
=D0=BF=D0=BE=D1=82=D1=80=D0=B5=D0=B1=D1=
83=D0=B5=D1=82=D1=81=D1=8F =D1=83=
=D1=81=D1=82=D0=B0=D0=BD=D0=BE=D0=B2=D0=
B8=D1=82=D1=8C/=D1=81=D0=BD=D1=8F=
=D1=82=D1=8C???
ti.c_cc[VMIN] =3D 0;
ti.c_cc[VTIME] =3D 0;
if (tcsetattr(port->fd, TCSANOW, &ti) < 0)
{ syslog(LOG_ERR,"%s(%s):error setting terminal line modes: %m",
__func__, devfile); close(port->fd);free(port); return
NULL; }
</code>
any idea???
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