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Diffstat (limited to 'man/man4/lp.4')
| -rw-r--r-- | man/man4/lp.4 | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/man/man4/lp.4 b/man/man4/lp.4 new file mode 100644 index 0000000..8b3e722 --- /dev/null +++ b/man/man4/lp.4 @@ -0,0 +1,137 @@ +'\" t +.\" Copyright (c) Michael Haardt (michael@cantor.informatik.rwth-aachen.de), +.\" Sun Jan 15 19:16:33 1995 +.\" +.\" SPDX-License-Identifier: GPL-2.0-or-later +.\" +.\" Modified, Sun Feb 26 15:02:58 1995, faith@cs.unc.edu +.TH lp 4 2024-05-02 "Linux man-pages (unreleased)" +.SH NAME +lp \- line printer devices +.SH SYNOPSIS +.nf +.B #include <linux/lp.h> +.fi +.SH CONFIGURATION +\fBlp\fP[0\[en]2] are character devices for the parallel line printers; +they have major number 6 and minor number 0\[en]2. +The minor numbers +correspond to the printer port base addresses 0x03bc, 0x0378, and 0x0278. +Usually they have mode 220 and are owned by user +.I root +and group +.IR lp . +You can use printer ports either with polling or with interrupts. +Interrupts are recommended when high traffic is expected, for example, +for laser printers. +For typical dot matrix printers, polling will usually be enough. +The default is polling. +.SH DESCRIPTION +The following +.BR ioctl (2) +calls are supported: +.TP +.BR "int ioctl(int " fd ", LPTIME, int " arg ) +Sets the amount of time that the driver sleeps before rechecking the printer +when the printer's buffer appears to be filled to +.IR arg . +If you have a fast printer, decrease this number; +if you have a slow printer, then increase it. +This is in hundredths of a second, the default 2 +being 0.02 seconds. +It influences only the polling driver. +.TP +.BR "int ioctl(int " fd ", LPCHAR, int " arg ) +Sets the maximum number of busy-wait iterations which the polling driver does +while waiting for the printer to get ready for receiving a character to +.IR arg . +If printing is too slow, increase this number; if the +system gets too slow, decrease this number. +The default is 1000. +It influences only the polling driver. +.TP +.BR "int ioctl(int " fd ", LPABORT, int " arg ) +If +.I arg +is 0, the printer driver will retry on errors, otherwise +it will abort. +The default is 0. +.TP +.BR "int ioctl(int " fd ", LPABORTOPEN, int " arg ) +If +.I arg +is 0, +.BR open (2) +will be aborted on error, otherwise error will be ignored. +The default is to ignore it. +.TP +.BR "int ioctl(int " fd ", LPCAREFUL, int " arg ) +If +.I arg +is 0, then the out-of-paper, offline, and error signals are +required to be false on all writes, otherwise they are ignored. +The default is to ignore them. +.TP +.BR "int ioctl(int " fd ", LPWAIT, int " arg ) +Sets the number of busy waiting iterations to wait before strobing the +printer to accept a just-written character, and the number of iterations to +wait before turning the strobe off again, +to +.IR arg . +The specification says this time should be 0.5 +microseconds, but experience has shown the delay caused by the code is +already enough. +For that reason, the default value is 0. +.\" FIXME . Actually, since Linux 2.2, the default is 1 +This is used for both the polling and the interrupt driver. +.TP +.BR "int ioctl(int " fd ", LPSETIRQ, int " arg ) +This +.BR ioctl (2) +requires superuser privileges. +It takes an +.I int +containing the new IRQ as argument. +As a side effect, the printer will be reset. +When +.I arg +is 0, the polling driver will be used, which is also default. +.TP +.BR "int ioctl(int " fd ", LPGETIRQ, int *" arg ) +Stores the currently used IRQ in +.IR arg . +.TP +.BR "int ioctl(int " fd ", LPGETSTATUS, int *" arg ) +Stores the value of the status port in +.IR arg . +The bits have the following meaning: +.TS +l l. +LP_PBUSY inverted busy input, active high +LP_PACK unchanged acknowledge input, active low +LP_POUTPA unchanged out-of-paper input, active high +LP_PSELECD unchanged selected input, active high +LP_PERRORP unchanged error input, active low +.TE +.IP +Refer to your printer manual for the meaning of the signals. +Note that undocumented bits may also be set, depending on your printer. +.TP +.BR "int ioctl(int " fd ", LPRESET)" +Resets the printer. +No argument is used. +.SH FILES +.I /dev/lp* +.\" .SH AUTHORS +.\" The printer driver was originally written by Jim Weigand and Linus +.\" Torvalds. +.\" It was further improved by Michael K.\& Johnson. +.\" The interrupt code was written by Nigel Gamble. +.\" Alan Cox modularized it. +.\" LPCAREFUL, LPABORT, LPGETSTATUS were added by Chris Metcalf. +.SH SEE ALSO +.BR chmod (1), +.BR chown (1), +.BR mknod (1), +.BR lpcntl (8), +.BR tunelp (8) |