On Monday 12 May 2008, Kevin J. Cummings wrote: >Gene Heskett wrote: >-- >Kevin J. Cummings >kjchome@xxxxxxx >cummings@xxxxxxxxxxxxxxxxxx >cummings@xxxxxxxxxxxxxxxxxxxxxxx >Registered Linux User #1232 (http://counter.li.org) > >> On Monday 12 May 2008, Mikkel L. Ellertson wrote: >>> Gene Heskett wrote: >>>> But, this command line, which outputs to the screen very nicely if the >>>> pipe and the rest of the line are removed, seems to send the data to >>>> /dev/null: >>>> >>>> #>cat /dev/ttyUSB1 | lpr -Plp1 >>> >>> Try something like: >>> cat /dev/ttyUSB1 | lpr -Plp1 - >>> or >>> cat /dev/ttyUSB1 | lpr -Plp1 -- - >> >> Either of those give this: >> [root@coyote ~]# cat /dev/ttyUSB1 | lpr -Plp1 - >> lpr: Error - unknown option ' >> ^C >> [root@coyote ~]# cat /dev/ttyUSB1 | lpr -Plp1 -- - >> lpr: Error - unknown option '-'! >> >> Thanks. >> >>> From the lp man page: >>> lp submits files for printing or alters a pending job. Use a >>> filename of "-" to force printing from the standard input. > > From the lpr man page: >> lpr submits files for printing. Files named on the command line are >> sent to the named printer (or the system default destination if no >> destination is specified). If no files are listed on the command-line, lpr >> reads the print file from the standard input. > >So: > >cat /dev/ttyUSB1 | lpr -Plp1 > >should be all that's needed.... sorry about the late rely here Kevin. The above example, except to -Plp3, has been running for about 4 hours, and I have sent 11 copies of that directory listing up the /dev/ttyUSB1 cable now with nothing going to that printer, or when changed to lp1 which is right beside me. Neither that, nor a cat /dev/ttyUSB1 | lp -d lp3 - works, both apparently doing exactly the same thing with the data, stuffing it into a file in /tmp, which is not printed, and which is deleted if I ctl-c the command line. That has resulted in some activity I can see with htop, for both cat and lpr, and there is now a file of some 105k in /tmp that contains these directory listings. The tail end of this /tmp/file looks like this in text format: [root@coyote tmp]# tail 482b58beea317 0 2008/05/13 21:00 --e-rewr 6B08 1B01 ed 0 2006/04/21 13:38 --e-rewr 1EF6C 16C wcreate 0 2006/04/21 13:38 --e-rewr 1EF70 439 xmode 0 2008/05/12 13:05 ------wr BFF4 211 GSort 0 2008/05/13 21:54 --e-rewr 3FF0 4EA noautoex 0 2008/05/13 21:09 --e-rewr FEDC 4EA multivue 0 1995/04/30 16:30 ----rewr FFF8 39BF GShell 0 1987/09/29 19:27 --e-rewr 1ECAC 3A6E Control 0 1988/02/19 20:02 --e-rewr 1ECB4 1DE compare And in hexdump -C format: 00003c20 38 20 20 20 20 20 20 33 39 42 46 20 47 53 68 65 |8 39BF GShe| 00003c30 6c 6c 0a 20 20 20 30 20 20 31 39 38 37 2f 30 39 |ll. 0 1987/09| 00003c40 2f 32 39 20 31 39 3a 32 37 20 20 2d 2d 65 2d 72 |/29 19:27 --e-r| 00003c50 65 77 72 20 20 20 31 45 43 41 43 20 20 20 20 20 |ewr 1ECAC | 00003c60 20 33 41 36 45 20 43 6f 6e 74 72 6f 6c 0a 20 20 | 3A6E Control. | 00003c70 20 30 20 20 31 39 38 38 2f 30 32 2f 31 39 20 32 | 0 1988/02/19 2| 00003c80 30 3a 30 32 20 20 2d 2d 65 2d 72 65 77 72 20 20 |0:02 --e-rewr | 00003c90 20 31 45 43 42 34 20 20 20 20 20 20 20 31 44 45 | 1ECB4 1DE| 00003ca0 20 63 6f 6d 70 61 72 65 0a 0a 1b | compare...| perhaps there is a clue here, like some control character missing? As the src machine is not sending \n's, only \r's, /dev/ttyUSB1 is set to translate \r's to \n's with stty options. Does it need an EOF ($1B) to trigger the actual printing? I'm not sure I can make the src machine do that, but I'll try. Yes, I could, but as a separate line of the program and it shows in the above hexdump. As a test its ok, but for day to day operations it would be a dud. lpr is the owner of this file according to "lsof|grep lpr": lpr 3533 root 4u REG 8,3 15531 82903079 /tmp/482b9fa495624 And just now, switching screens, I locked the machine up tight and had to hit the reset button. 6 day uptime for 2.6.26-rc1 wrecked. Perhaps the trigger for lpr to actually print it is some other control character? I'm bumfuzzled to be sure, 2 days of screwing with this. Many thanks, to Kevin J. Cummings, or anyone else who can shed some light on this. >-- >Kevin J. Cummings >kjchome@xxxxxxx >cummings@xxxxxxxxxxxxxxxxxx >cummings@xxxxxxxxxxxxxxxxxxxxxxx >Registered Linux User #1232 (http://counter.li.org) -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) The Edsel. New Coke. Windows 2000. All mandatory case studies for bizschool students in 2020. -- Bear Giles (in a LinuxToday post) -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list
