Setting up lp for PC

[Luther Huffman, Jr. lutherh@mail.infinet.com]

Thanks! And, boy, am I glad the solution didn't make me feel 
bone/stick/stone stupid for not figuring it out for myself (e.g., 
setting up swap for my system took only changing two lines in termrc; 
or installing the kernel by copying 9pcdisk to /dev/hd1boot).  Plan 9 
has done a marvelous job of keeping my ego in check.  =;-)


On  8 Jan 96 at 9:31, G. David Butler wisely noted:

> This is how I added a postscript printer on serial port
> eia1 on a PC cpu server named cpu1.
> 
> To drive a printer on the parallel port, a different
> approach is required since tcpostio requires feedback
> from the printer and the parallel interface is one way.
> Basically a lptsrv needs to be written that opens
> /dev/lpt1data write only and emulates the responses
> from tcpostio.  A simpler approach would be to change
> the daemon side alltogether so it doesn't chat with
> the printer.
> 
> Since I have a file server that does *NOT* have a WORM,
> I have all the cpus and terminals share the /sys/lib/lp
> directory and use the queue and tmp directories there.
> (In other words, no bootes "other" file system.)
> 
> After these changes, one can print from the cpu console
> and any terminal or cpu window.
> 
> I would like to have some feedback to the code in eiasrv.c.
> Did I do all the "proper" Plan 9 things?
> 
> Enjoy.
> 
> David Butler
> gdb@dbSystems.com
> 
> 
> ==================================================
> add to /sys/lib/lp/devices: (line broken for readability)
> ps	Office	cpu1	/srv/eia1	512	post+nohead	generic
> generic	generic	generic	tcppost	FIFO
> 
> ==================================================
> /sys/lib/lp/bin/lpsend.rc (/sys/src/cmd/lp/lpsend.rc):
> diff -e lpsend.rc.cdrom lpsend.rc
> 24,32c
> #if (test -e /net/dk/clone || import helix /net/dk) {
> # 	dialstring=`{ndb/query sys $1 dk}
> #	network=dk
> #	if (! ~ $dialstring '') {
> #		if(lpsend $dialstring $network printer) exit ''
> #	}
> #	rv=$rv^', dk failed'
> #}
> #if not rv=$rv^', no dk'
> .
> 5c
> if (test -e /net/tcp/clone || import cpu1 /net/tcp) {
> .
> 
> ==================================================
> /rc/bin/lp (/sys/src/cmd/lp/lp.rc):
> diff -e lp.rc.cdrom lp.rc
> 17,21c
> #if (! test -r /srv/bootes) srv -m bootes
> #if (! mount -c /srv/bootes /n/bootesother other || ! bind -a
> #/n/bootesother/lp /sys/lib/lp) { 	echo 'could not properly setup
> #LPSPOOL' >[1=2] 	exit 'LPSPOOL setup'
> #}
> .
> 
> ==================================================
> /386/bin/aux/lpdaemon (/sys/src/cmd/lp/lpdaemon.c):
> diff -e lpdaemon.c.cdrom lpdaemon.c
> 423a
>   ACK();
> .
> 153c
>  return(fd);
> .
> 151d
> 146c
>  close(fd);
>  if((fd=open(tmpf, 2)) < 0) {
> .
> 141c
>  if((fd=creat(tmpf, 0666)) < 0) {
> .
> 137,138c
>  char tmpf[100];
>  int fd;
> .
> 92a
> #else
>  fputs(s1, fp);
> #endif
> .
> 91a
> #ifndef PLAN9
> .
> 90a
> #else
>  vfprintf(fp, s1, ap);
> #endif
> .
> 89a
> #ifndef PLAN9
> .
> 79a
> #endif
> .
> 77a
> #ifndef PLAN9
> .
> 
> ==================================================
> /386/bin/aux/tcpostio (/sys/src/cmd/postscript/tcpostio.l):
> diff -e tcpostio.l.cdrom tcpostio.l
> 412c
>     fprint(2, ". %5.2f%% sent, %.100s\n",
>     bytes_sent*100.0/bytes_to_send, statusbuf);
> .
> 283c
>     blocksize = atoi(av);
> .
> 197c
> byte statusbuf[PRBUFSIZ];
> .
> 177c
>    if (write(printerfd, "\004", 1) != 1) {
> .
> 162c
>      if (write(printerfd, "\004", 1) != 1) {
> .
> 149c
>    if (write(printerfd, "\024", 1) != 1) {
> .
> 123,124c
>     if (*(ke = find(ks, ":")) == '\0') {
>      return(PR_UNKNOWN);
>     }
>     kl = ke - ks;
> .
> 120a
>     return(statuslist[i].val);
> .
> 117,118c
>       break;
> .
> 103c
>    vl = ve - vs;
> .
> 91,92c
>   if (*(ke = find(ks, ":")) == '\0') {
>    return(PR_UNKNOWN);
>   }
>   kl = ke - ks;
> .
> 59c
>  { nil, PR_UNKNOWN }
> .
> 
> ==================================================
> /386/bin/aux/eiasrv (/sys/src/cmd/aux/eiasrv.c):
> cat eiasrv.c
> /*
>  * Copyright (c) 1996 G. David Butler
>  * All Rights Reserved.
>  *
>  * Unrestricted use of this source is granted as long as
>  * the above copyright remains.
>  */
> 
> #include <u.h>
> #include <libc.h>
> 
> #define PRBUFSIZ 8192	/* from
> #/sys/src/cmd/postscript/tcpostio/tcpostio.h */
> 
> char Srvfilename[256];
> int Childpid;
> 
> /* remove the /srv entry and kill the child at exit */
> void
> cleanup(void)
> {
>  remove(Srvfilename);
>  postnote(PNPROC, Childpid, "kill");
> }
> 
> /* on interrupt, if in the child writing to pipe, OK */
> /* else, cleanup and exit */
> int
> notehandler(void *, char *note) {
>  static char *pipenote = "sys: write on closed pipe";
> 
>  if (strncmp(note, pipenote, sizeof(pipenote) - 1) == 0) {
>   return 1;
>  }
>  cleanup();
>  return 0;
> }
> 
> void
> main(int argc, char *argv[])
> {
>  int blocksize;	/* see tcpostio.l about this */
>  int baud;		/* rate of the serial device */
>  int outputfd;	/* fd to serial device */
>  int inputfd;	/* fd from pipe on /srv */
>  int pipefd[2];
>  char buf[PRBUFSIZ];
> 
>  blocksize = PRBUFSIZ;
>  baud = 9600;	/* default rate */
> 
>  ARGBEGIN {
>  case 'B':
>   blocksize = atoi(ARGF());
>   break;
>  case 'b':
>   baud = atoi(ARGF());
>   break;
>  default:
>   fprint(2, "%s: badflag('%c')\n", argv0, ARGC());
>   break;
>  } ARGEND
> 
>  if (argc != 1 || baud == 0) {
>   fprint(2, "Usage: %s [-B blocksize] [-b baud] device\n", argv0);
>   exits("fatal");
>  }
> 
>  if (blocksize < 1 || blocksize > PRBUFSIZ) {
>   blocksize = PRBUFSIZ;
>  }
> 
>  if ((outputfd = open(*argv, ORDWR)) < 0) {
>   fprint(2, "%s: open of (%s) failed: %r\n", argv0, *argv);
>   exits("fatal");
>  }
> 
>  /* set the port up correctly for I/O */
>  sprint(Srvfilename, "%sctl", *argv);
>  if ((inputfd = open(Srvfilename, OWRITE)) < 0) {
>   fprint(2, "%s: open of (%s) failed: %r\n", argv0, Srvfilename);
>   exits("fatal");
>  }
> 
>  sprint(buf, "b%d", baud);
>  if (write(inputfd, buf, strlen(buf)) < 0 ||
>      write(inputfd, "d1", 2) < 0 ||
>      write(inputfd, "r1", 2) < 0 ||
>      write(inputfd, "m1", 2) < 0 ||
>      write(inputfd, "pn", 2) < 0 ||
>      write(inputfd, "s1", 2) < 0 ||
>      write(inputfd, "l8", 2) < 0) {
>   fprint(2, "%s: write to (%s) failed: %r\n", argv0, Srvfilename);
>   exits("fatal");
>  }
>  close(inputfd);
> 
>  /* this is the name of our "named pipe" */
>  sprint(Srvfilename, "/srv%s", strrchr(*argv, '/'));
>  if ((inputfd = create(Srvfilename, OWRITE, 0666)) < 0) {
>   fprint(2, "%s: create of (%s) failed: %r\n", argv0, Srvfilename);
>   exits("fatal");
>  }
> 
>  atexit(cleanup);
> 
>  if (pipe(pipefd) < 0) {
>   fprint(2, "%s: pipe failed: %r\n", argv0);
>   exits("fatal");
>  }
> 
>  sprint(buf, "%d", pipefd[0]);
>  if (write (inputfd, buf, strlen(buf)) < 0) {
>   fprint(2, "%s: write to (%s) failed: %r\n", argv0, Srvfilename);
>   exits("fatal");
>  }
> 
>  close(inputfd);
>  close(pipefd[0]);
>  inputfd = pipefd[1];
> 
>  atnotify(notehandler, 1);
> 
>  /* the parent and child can share */
>  if (Childpid = rfork(RFPROC)) {
> 
>   while ((pipefd[0] = read(inputfd, buf, blocksize)) >= 0) {
>    pipefd[1] = 0;
>    while (pipefd[1] < pipefd[0]) {
>     if ((baud = write(outputfd, buf, pipefd[0])) < 0) {
>      fprint(2, "%s: parent write failed: %r\n", argv0);
>      exits("fatal");
>     }
>     pipefd[1] += baud;
>    }
>   }
> 
>   if (pipefd[0] < 0) {
>    fprint(2, "%s: parent read failed: %r\n", argv0);
>    exits("fatal");
>   } else {
>    exits("");
>   }
> 
>  } else {
> 
>   while ((pipefd[0] = read(outputfd, buf, blocksize)) >= 0) {
>    pipefd[1] = 0;
>    while (pipefd[1] < pipefd[0]) {
>     if ((baud = write(inputfd, buf, pipefd[0])) < 0) {
>      buf[0] = '\0';
>      errstr(buf);
>      if (strcmp(buf, "interrupted") == 0) {
>       pipefd[1] = pipefd[0];
>       continue;
>      } else {
>       fprint(2, "%s: child write failed: %s\n", argv0, buf);
>       exits("fatal");
>      }
>     }
>     pipefd[1] += baud;
>    }
>   }
> 
>   if (pipefd[0] < 0) {
>    fprint(2, "%s: child read failed: %r\n", argv0);
>    exits("fatal");
>   } else {
>    exits("");
>   }
>  }
> }
> 
> 
> ==================================================
> /sys/src/cmd/aux/mkfile:
> diff -e mkfile.cdrom mkfile
> 10a
>  eiasrv\
> .
> 
> 
> ==================================================
> /rc/bin/cpurc:
>  add a line to your cpu server bootup like:
>   aux/eiasrv -b 38400 /dev/eia1 &
> 
>