NAME
printcap – printer capability database
DESCRIPTION
The printcap file is a simplified version of the termcap(5) database used to describe line printers. The spooling system accesses the printcap file every time it is used, allowing dynamic addition and deletion of printers. Each entry in the database is used to describe one printer. This database may not be substituted for, as is possible for termcap(5), because it may allow accounting to be bypassed.
The default printer is normally “lp”, though the environment variable PRINTER may be used to override this. Each spooling utility supports an option, -Pprinter, to allow explicit naming of a destination printer.
Refer to the for a complete discussion on how to set up the database for a given printer.
CAPABILITIES
Refer to termcap(5) for a description of the file layout.
| Name | Type | Default | Description |
| af | str | NULL | name of accounting file |
| br | num | none | if lp is a tty, set baud rate |
| cf | str | NULL | cifplot data filter |
| df | str | NULL | tex data filter (DVI format) |
| ff | str | ‘\f’ | string to send for a form feed |
| fo | bool | false | print a form feed when device is opened |
| gf | str | NULL | graph data filter |
| hl | bool | false | print the burst header page last |
| ic | bool | false | supports non-standard ioctl to indent printout |
| if | str | NULL | name of text filter which does accounting |
| lf | str | /dev/console | error logging file name |
| lo | str | lock | name of lock file |
| lp | str | /dev/lp | local printer device, or port@host for remote |
| mc | num | 0 | maximum number of copies allowed; 0=unlimited |
| ms | str | NULL | if lp is a tty, a comma-separated, |
| mx | num | 0 | max file size (in |
| nd | str | NULL | next directory for queues list (unimplemented) |
| nf | str | NULL | ditroff data filter (device independent troff) |
| of | str | NULL | name of output filtering program |
| pc | num | 200 | price per foot or page in hundredths of cents |
| pl | num | 66 | page length (in lines) |
| pw | num | 132 | page width (in characters) |
| px | num | 0 | page width in pixels (horizontal) |
| py | num | 0 | page length in pixels (vertical) |
| rf | str | NULL | filter for printing FORTRAN style text files |
| rg | str | NULL | restricted group-only group members can access |
| rm | str | NULL | machine name for remote printer |
| rp | str | ``lp'' | remote printer name argument |
| rs | bool | false | remote users must have a local account |
| rw | bool | false | open printer device for reading and writing |
| sb | bool | false | short banner (one line only) |
| sc | bool | false | suppress multiple copies |
| sd | str | /var/spool/output/lpd | spool directory |
| sf | bool | false | suppress form feeds |
| sh | bool | false | suppress printing of burst page header |
| st | str | status | status file name |
| tf | str | NULL | troff data filter (C/A/T phototypesetter) |
| tr | str | NULL | trailer string to print when queue empties |
| vf | str | NULL | raster image filter |
The classic port number used for remote printing is printer (515). Many newer printers work better with jetdirect (9100).
If the local line printer driver supports indentation, the daemon must understand how to invoke it.
FILTERS
If a printer is specified via lp (either local or remote), the lpd(8) daemon creates a pipeline of “filters” to process files for various printer types. The pipeline is not set up for remote printers specified via rm unless the local host is the same as the remote printer host given. The filters selected depend on the flags passed to lpr(1). The pipeline set up is:
p pr | if regular text + pr(1) none if regular text c cf cifplot d df DVI (tex) g gf plot(3) n nf ditroff f rf Fortran t tf troff v vf raster image
The if filter is invoked with arguments:
if [-c] -wwidth -llength -iindent -n login -h host acct-file
The -c flag is passed only if the -l flag (pass control characters literally) is specified to lpr(1). width and length specify the page width and length (from pw and pl, respectively) in characters. The -n and -h parameters specify the login name and host name of the owner of the job, respectively. The acct-file function is passed from the af printcap entry.
If no if is specified, of is used instead, with the distinction that of is opened only once, while if is opened for every individual job. Thus, if is better suited to performing accounting. The of is only given the width and length flags.
All other filters are called as:
filter -xwidth -ylength -n login -h host acct-file
where width and length are represented in pixels, specified by the px and py entries, respectively. All filters take stdin as the file, stdout as the printer, may log either to stderr or using syslog(3), and must not ignore SIGINT.
LOGGING
Error messages generated by the line printer programs themselves are logged by syslog(3) using the LPR facility. Messages printed on stderr by the filters are sent to the corresponding lf file. The filters may, of course, use syslog(3) themselves.
Error messages sent to the console have a carriage return and a line feed appended to them, rather than just a line feed.
FILES
- /etc/printcap
-
Default location of the database file.
- /etc/examples/printcap
-
Example database file.
SEE ALSO
lpq(1), lpr(1), lprm(1), termcap(5), lpc(8), lpd(8) 4.3 BSD Line Printer Spooler Manual.
HISTORY
The printcap file format appeared in 4.2BSD.