SCO Unix/System V Printing FAQ
This is caused by the different ways that DOS and Unix handle the end of a text line. Unix ends a line with a LF (Line Feed, 0x0A) character, while DOS uses both a LF and a CR (Carriage Return, 0x0D).
In Linux, your printer setup tool should offer this translation as an option.
Staircase is when you printer prints like this:
Everything starts out OK, but when you reach the end of a line, it moves down but not back
(With a laser printer, the same problem will cause only one or even no lines to print)
If a printer is expecting both characters, getting only a LF tells it to only do a Line Feed without a Carriage Return, so that's just what it does, and that's just what you get.
There are at least five ways to fix this:
- Change the printer so that it generates a CR when it gets a line feed. Most printers can do this, and if you use it for DOS, it just means there is an "extra" CR, which changes nothing. This is done with dip switches or a printer configuration panel.
- Change the printer by sending it whatever escape sequences it needs to add CR's to LF's. This is going to vary, and you are going to need to add it in the interface script low enough that it doesn't get reset by some other command being sent out.
- (Linux)Filter the output through "todos". This involves piping the output through that on it's way out: " cat printfile.txt | todos | lpr". If you wanted to do more, perl -ne 'chop; print $_,"\r\n"' takes care of the translation part and you could add more.
- (SCO) Filter the output through /usr/lib/lponlcr or xtod. This involves piping the output through that on it's way out. In the "standard" script, you might set "FILTER=/usr/lib/lponlcr". In other scripts, just add " | /usr/lib/lponlcr" on the line that cats the file.
- (SCO) Set the "stty onlcr opost" in the interface script. This can be done from the printer manager on Release 4 and 5, or by using the "crnlmap" model; unfortunately it does not always work (for example, it can't work for network printers). See: /Unixart/netprint.html
- (SCO) Move the "stty onlcr opost" to a "hold-open" script (see the article on serial printers) for this port. This works, but it's annoying, and again won't work for network printers.
(SCO) If you are using an HP network printer, you can add "-n" or even
"-N" to the the interface.
Don't add it to the "HPNPF=" line; add it in the line(s) that
actually uses $HPNPF. For example, you'd change
if $REALMODEL "$@" | $HPNPF -x $PERIPH 2> $LOG > /dev/null to if $REALMODEL "$@" | $HPNPF -x $PERIPH -n 2> $LOG > /dev/nullYou can download http://aplawrence.com/pub/netcat.hp.model See man hpnpf
David DiPieto offered these thoughts:
Date: Tue, 29 Dec 1998 16:05:40 -0500 From: David DiPietro <firstname.lastname@example.org> To: email@example.com Subject: printer stairstepping ... Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit I thought I'd share a little opost experience with you. When I install our application software I automatically add a "holdopen" for each parallel and serial printer to append the <cr> to <lf> as you mention in your printer discussion. Most of our sites now involve some kind of networking and printer sharing. I had been putting the high-speed lasers on the parallel ports on the SCO Unix server but starting having a problem with Windows applications printing graphics. I would often loose data or get garbled graphics. I finally decided to take the time to figure out what was going on using the hex dump mode on a Lexmark Laser. Apparently, and with understanding, having opost onlcr turned on will do a straight binary filter of the printer data replacing all <nl> with <cr><nl> - even if it occurs in the middle of a raster graphics string. This could - and will most likely - reak havoc on the output! You may want to address this in your discussion. In my case, the problem was solved completely by turning on the auto <cr> at the printer. Dave DiPietro/Abacus Systems Inc. (973) 875-9900
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