/* -------------------------------------------------------------------- * $Id: bla_serial_terminal.c,v 1.3 2009/01/24 15:50:00 akurz Exp $ * simple serial line terminal * * Copyright 2006 by Alexander Kurz * * This is free software. * You may copy and redistibute this software according to the * GNU public Licence 2 or any later verson. * * ----------------------------------------------------------------- */ #include // stat #include // stat #include // serial line stuff #include // O_NONBLOCK flags #include // read() #include #include #include #define MAX_STRLEN 4096 /* ------------ global ------------ */ struct termios oldtio_l, oldtio_c; /*-------- print usage-information ------------------------*/ void usage(char* prog){ fprintf(stderr, "Usage: %s [option(s)]\n" "without options, connect 9600n81 to /dev/ttyS0\n" "type ^X to exit\n" " -h, --help print this help-information and exit\n" " -v, --version print version and exit\n\n", prog); } /*-------- check TTY speed --------------------------------*/ speed_t check_termios_speed(const int rate) { switch(rate) { case 50: return B50; case 75: return B75; case 150: return B150; case 300: return B300; case 600: return B600; case 1200: return B1200; case 2400: return B2400; case 4800: return B4800; case 9600: return B9600; case 19200: return B19200; case 38400: return B38400; default: fprintf(stderr,"unsupported TTY speed"); } return B0; } /*-------- check and open TTY device ----------------------*/ int check_open_tty(const char* ttyport) { int fd; /* --------- check tty port */ struct stat buf; if (stat(ttyport,&buf)!=0) { fprintf(stderr,"%s: %s\n",ttyport,strerror(errno)); return -1; } if (!S_ISCHR(buf.st_mode)) { fprintf(stderr,"%s is not a char device\n",ttyport); return -1; } /* --------- open tty port */ fd = open(ttyport, O_RDWR|O_NONBLOCK|O_NOCTTY); if (fd<0) { fprintf(stderr,"%s: %s\n",ttyport,strerror(errno)); } return fd; } /*-------- save old and set new TTY settings --------------*/ int set_termios(int fd, struct termios* oldtio_p, const speed_t termios_speed) { struct termios newtio; memset(&newtio, 0, sizeof(newtio)); /* --------- save old and set new tty parameters */ if( tcgetattr(fd,oldtio_p) == -1 ){ perror("failed to save old tty state"); return 1; } /* --- control flags */ /* 8 bits/byte, ignore modem control lines */ newtio.c_cflag |= CS8 | CLOCAL | CREAD; /* 8 bits/byte, ignore modem control lines, hardware flow control */ /* newtio.c_cflag |= CS8 | CLOCAL | CREAD | CRTSCTS; */ /* --- output flags */ /* baud rate */ cfsetospeed(&newtio,termios_speed); /* output processing off */ newtio.c_oflag &= ~(OPOST); /* --- input flags */ /* input speed same as output speed */ cfsetispeed(&newtio,0); /* dont ignore input parity errors */ /* newtio.c_iflag &= ~IGNPAR;*/ /* enable software flow control */ /* newtio.c_iflag |= (IXON | IXOFF); */ /* disable software flow control */ newtio.c_iflag &= ~(IXON | IXOFF); /* no SIGINT on BREAK, CR to NL off, input pariry check off, dont strip 8th bit */ newtio.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON ); /* --- local flags */ /* set echo off, input non-canonical mode, no extended input processing, no signal chars */ newtio.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG); /* --- control chars */ /* inter-character timer unused, blocking read until 1 chars received */ newtio.c_cc[VTIME] = 0; newtio.c_cc[VMIN] = 1; /* --- flush old bits out of the input buffer */ if( tcflush(fd, TCIFLUSH) == -1 ){ perror("flush tty"); return 1; } /* --- write new port settings */ if( tcsetattr(fd,TCSANOW,&newtio) == -1 ){ perror("write new tty settings"); return 1; } return 0; } int main(int argc, char** argv) { int fd; int baudrate=9600; const char ttyport[] = "/dev/ttyS0"; speed_t termios_speed; fprintf(stderr,"type ^X to exit\n"); if ((termios_speed = check_termios_speed(baudrate))==B0) return 1; if ((fd = check_open_tty(ttyport))<0) return 1; if (set_termios(fd, &oldtio_l, termios_speed)==-1) return 1; if (set_termios(0, &oldtio_c, termios_speed)==-1) return 1; /* --------- port is ready now */ if(1) { struct timeval tv; fd_set readfds; int responsetime=3*1000; unsigned int size=MAX_STRLEN; int num = 0; /* number of new bytes read */ int eoc = 0; /* end of communication, nothing new read */ int quit = 0; char buf[MAX_STRLEN]; while(!quit) { eoc = 0; tv.tv_sec = (int)(responsetime/1000); tv.tv_usec = 1000*(responsetime-1000*(int)(responsetime/1000)); while(!eoc){ FD_ZERO(&readfds); FD_SET(fd,&readfds); /* tty-Port */ FD_SET(0,&readfds); /* stdin */ if (select(fd+1,&readfds,NULL,NULL,&tv)==-1){ fprintf(stderr,"error: ttyport %s: %s\n",ttyport,strerror(errno)); return 1; } if (!(FD_ISSET(fd, &readfds)|FD_ISSET(0, &readfds))){ // select timeout eoc = 1; }else{ if (FD_ISSET(fd, &readfds)){ num = read(fd,buf,size); if (num<0){ fprintf(stderr,"error: ttyport %s: %s\n",ttyport,strerror(errno)); return 1; }else if (num==0){ /* fd is set, but nothing was there to read ---> finish */ eoc = 1; }else{ tv.tv_sec = (int)(responsetime/1000); tv.tv_usec = 1000*(responsetime-1000*(int)(responsetime/1000)); if (write(1,buf,num) != num) { fprintf(stderr,"error: partial/no write %i\n",num); return 1; } } } if (FD_ISSET(0, &readfds)){ num = read(0,buf,size); if (num<0){ fprintf(stderr,"error: stdin: %s\n",strerror(errno)); return 1; }else if (num==0){ /* fd is set, but nothing was there to read ---> finish */ eoc = 1; }else{ tv.tv_sec = (int)(responsetime/1000); tv.tv_usec = 1000*(responsetime-1000*(int)(responsetime/1000)); buf[num] = '\0'; if (buf[0] == '\30') { quit=1; break; } if (write(fd,buf,num) != num) { fprintf(stderr,"error: partial/no write %i\n",num); return 1; } tcdrain(fd); /* wait until all data is written */ } } } } } } /* --------- restore old tty parameters, cleanup */ tcsetattr(fd,TCSANOW,&oldtio_l); tcsetattr(0,TCSANOW,&oldtio_c); close(fd); return 0; }