Re: [SLUG] A simple script and printing question (?)

From: Eben King (
Date: Thu Apr 13 2006 - 13:05:41 EDT

On Thu, 13 Apr 2006, Macy1 Hallock wrote:

> Eben King wrote:
>> On Wed, 12 Apr 2006, Macy1 Hallock wrote:
>>> I'm hacking a vendors ancient COBOL program output to print using lpr (via
>>> cups) in Fedora.
>>> Given a program output similar to that produced by "cat textfile.txt >"
>>> If I append the sting "/dev/ttyS01" it prints to the serial port. But I
>>> want to print using the cups spooler. I can't using lpr, because the pipe
>>> metacharacter won't function.
>>> So, how can I print the stdout via lpr under cups, not using a pipe?
>>> Note that I can't modify the command shown in quotes, I can only append to
>>> it, and there's a 15 character field limit to boot.
>> Dump to a temp file, and print that? "cat textfile.txt >/tmp/x;lpr x" will
>> fit (10 chars) and sorta work. Unless /tmp/x already exists. Don't know a
>> way to cram even basic security in 15 chars.
> Clever enough, but doesn't work. Since I'm submitting a destination to a
> redirect, the semicolon does not work for command chaining.

OK, how about a wrapper then? In your wrapper script, run

cp /dev/null /tmp/foo
chmod 600 /tmp/foo

then tell the program to write to /tmp/foo, then in the wrapper run

lpr /tmp/foo

> Both Eben and Wayne suggested using a named pipe, which I thought would be a
> good solution. However, it does not work, error message returned by cups is
> lpr: unable to print file: client-error-bad-request

Of course, if the program repeatedly does something like (open the file,
send som text, close the file), then maybe something like "tail -f" is in
order. I wonder what lpr's beef was. Is there anything in a log?

Maybe you can use the "named pipe" trick, with a script reading from it,
writing whatever it reads to a file, and later printing that file.

Does this COBOL program output text or binary data?

-eben    ebQenW1@EtaRmpTabYayU.rIr.OcoPm

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