Monitoring System Activity

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Fred wishes to see a printed listing of the file private.txt he would enter the

command:

lpr private.txt

If this is a busy system, Fred will not expect his job to print right away. He

can look at the position of his job in the queue using lpq to list the jobs waiting

in the print queue. This command lists the jobs in the queue, in the order they

will be printed. A job number is associated with each entry in the queue.

This number can be passed to lprm if it becomes necessary to remove a print

job from the queue. Fred can, of course, only remove his own jobs from the

queue, while the root account can remove any job found there.

If the file to be printed is more complex than simple ASCII text, then a filter

will need to be applied in the /etc/printcap file. Packages like magicfilter

provide a wide range of filters for most printers. These filters will allow you

to print PostScript files to a non PostScript printer. In combination with

programs like dvips (which converts a dvi file to PostScript output) the output

of almost any Linux file format can be converted and sent to the printer.