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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | FILES | NOTES | AVAILABILITY | COLOPHON |
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TUNELP(8) System Administration TUNELP(8)
tunelp - set various parameters for the lp device
tunelp [options] device
tunelp sets several parameters for the /dev/lp? devices, for
better performance (or for any performance at all, if your
printer won't work without it...) Without parameters, it tells
whether the device is using interrupts, and if so, which one.
With parameters, it sets the device characteristics accordingly.
-i, --irq argument
specifies the IRQ to use for the parallel port in
question. If this is set to something non-zero, -t and -c
have no effect. If your port does not use interrupts,
this option will make printing stop. The command tunelp
-i 0 restores non-interrupt driven (polling) action, and
your printer should work again. If your parallel port
does support interrupts, interrupt-driven printing should
be somewhat faster and efficient, and will probably be
desirable.
NOTE: This option will have no effect with kernel 2.1.131
or later since the irq is handled by the parport driver.
You can change the parport irq for example via
/proc/parport/*/irq. Read
/usr/src/linux/Documentation/admin-guide/parport.rst for
more details on parport.
-t, --time milliseconds
is the amount of time in jiffies that the driver waits if
the printer doesn't take a character for the number of
tries dictated by the -c parameter. 10 is the default
value. If you want fastest possible printing, and don't
care about system load, you may set this to 0. If you
don't care how fast your printer goes, or are printing
text on a slow printer with a buffer, then 500 (5 seconds)
should be fine, and will give you very low system load.
This value generally should be lower for printing graphics
than text, by a factor of approximately 10, for best
performance.
-c, --chars characters
is the number of times to try to output a character to the
printer before sleeping for -t TIME. It is the number of
times around a loop that tries to send a character to the
printer. 120 appears to be a good value for most printers
in polling mode. 1000 is the default, because there are
some printers that become jerky otherwise, but you must
set this to `1' to handle the maximal CPU efficiency if
you are using interrupts. If you have a very fast
printer, a value of 10 might make more sense even if in
polling mode. If you have a really old printer, you can
increase this further.
Setting -t TIME to 0 is equivalent to setting -c CHARS to
infinity.
-w, --wait milliseconds
is the number of usec we wait while playing with the
strobe signal. While most printers appear to be able to
deal with an extremely short strobe, some printers demand
a longer one. Increasing this from the default 1 may make
it possible to print with those printers. This may also
make it possible to use longer cables. It's also possible
to decrease this value to 0 if your printer is fast enough
or your machine is slow enough.
-a, --abort <on|off>
This is whether to abort on printer error - the default is
not to. If you are sitting at your computer, you probably
want to be able to see an error and fix it, and have the
printer go on printing. On the other hand, if you aren't,
you might rather that your printer spooler find out that
the printer isn't ready, quit trying, and send you mail
about it. The choice is yours.
-o, --check-status <on|off>
This option is much like -a. It makes any open(2) of this
device check to see that the device is on-line and not
reporting any out of paper or other errors. This is the
correct setting for most versions of lpd.
-C, --careful <on|off>
This option adds extra ("careful") error checking. When
this option is on, the printer driver will ensure that the
printer is on-line and not reporting any out of paper or
other errors before sending data. This is particularly
useful for printers that normally appear to accept data
when turned off.
NOTE: This option is obsolete because it's the default in
2.1.131 kernel or later.
-s, --status
This option returns the current printer status, both as a
decimal number from 0..255, and as a list of active flags.
When this option is specified, -q off, turning off the
display of the current IRQ, is implied.
-r, --reset
This option resets the port. It requires a Linux kernel
version of 1.1.80 or later.
-q, --print-irq <on|off>
This option sets printing the display of the current IRQ
setting.
/dev/lp?
/proc/parport/*/*
-o, -C, and -s all require a Linux kernel version of 1.1.76 or
later.
-C requires a Linux version prior to 2.1.131.
The tunelp command is part of the util-linux package and is
available from Linux Kernel Archive
⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩.
This page is part of the util-linux (a random collection of Linux
utilities) project. Information about the project can be found
at ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you
have a bug report for this manual page, send it to
util-linux@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
2021-03-21. (At that time, the date of the most recent commit
that was found in the repository was 2021-03-19.) If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for
the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original
manual page), send a mail to man-pages@man7.org
util-linux October 2011 TUNELP(8)
Pages that refer to this page: lp(4)
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