24.4 Text-Editing, Processing, and Printing

24.4.1 Objective 1: Perform Basic File-Editing Operations Using vi

• Start vi with vi file1 file2. See Table 24-2.

Table 24-2. Basic vi Editing Commands

Command	Description
ZZ	Write the file contents (if changed) and quit.
:x	Write the file contents (if changed) and quit (the ex equivalent of ZZ).
:q	Quit without saving changes.
:q!	Quit without saving changes and without confirmation.
:n	Next file. When multiple files are specified for editing, this command loads the next file.
Esc (the Escape key)	Exit insert mode and put the editor back into command mode.
h	Left one character.
j	Down one line.
k	Up one line.
l (ell)	Right one character.
0 (zero)	Beginning of the current line.
^	First non-whitespace character on the current line.
$	End of the current line.
H	Top of the screen.
L	Bottom of the screen.
G	End-of-file.
Ctrl-F	Down one screen.
Ctrl-B	Up one screen.
i	Enter insert mode to place text before the cursor.
a	Enter insert mode to place text after the cursor (append). This is necessary at the ends of lines.
C	Delete to end-of-line and enter insert mode.
R	Enter replace mode (a variant of insert mode) and overwrite existing characters.
dm	Delete a text block defined by a movement command m relative to the location where the command started.
dd	Delete the entire current line.
D	Delete to end-of-line (same as d$)
ym	Yank (copy) a text block defined by a movement command m relative to the location where the command started.
yy	Yank the entire current line.
P	Paste text on a line before the cursor.
p	Paste text on a line after the cursor.
/pattern	Search forward for pattern.
?pattern	Search backward for pattern.
n	Repeat the last search.
N	Repeat the last search in the opposite direction.

24.4.2 Objective 2: Manage Printers and Print Queues

• Printers are assigned to queues, which are managed by lpd , the print daemon. lpd listens for inbound print requests, forking a copy of itself for each active print queue.

• lpr submits jobs to print queues.

• lpq queries and displays queue status.

• lprm allows jobs to be removed from print queues.

• lpc allows root to administer queues; it has both interactive and command-line forms.

• filters translate data formats into a printer definition language.

• Spool directories hold spooled job data.

24.4.3 Objective 3: Print Files

• Files are printed with the lpr command:

# lpr /etc/lilo.conf
# man -t 5 myfile.txt | lpr -Pqueue2

24.4.4 Objective 4: Install and Configure Local and Remote Printers

24.4.4.1 /etc/printcap

• New printer definitions are added to /etc/printcap:

  lp|ljet:\
          :sd=/var/spool/lpd/lp:\
          :mx#0:\
          :sh:\
          :lp=/dev/lp0:\
          :if=/var/spool/lpd/lp/filter:
          :lf=/var/spool/lpd/lp/log:

  The lines in this example are defined as follows:

  lp|ljet:\

  This parameter defines two alternate names for the printer, lp or ljet.

  sd=spool_directory

  This parameter specifies the spool directory, under /var/spool/lpd.

  mx=max_size

  The maximum size of a print job in blocks. Setting this to #0 indicates no limit.

  sh

  Suppress header pages. Placing this attribute in printcap sets it, eliminating the headers.

  lp=printer_device

  The local printer device, such as a parallel port.

  if=input_filter

  The input filter to be used. See Section 24.4.4.2 for additional information.

  lf=log_file

  The file where error messages are logged.

24.4.4.2 Filters

• APSfilter is implemented as executable scripts. Installation configures /etc/printcap automatically. Multiple queues may be defined to give the user access to specific printer capabilities.

• Magicfilter is a binary program; installation does not automatically create print queues.

24.4.4.3 Remote queues and Samba printers

• Printing on a remote system or network printer is done through a local queue. /etc/printcap for the local queue looks something like this:

  rlp:\
          :sd=/var/spool/lpd/rlp:\
          :rm=lphost:\
          :rp=rlp:\
          :mx#0:\
          :sh:\
          :if=/usr/local/bin/magicfilter:

• Printing to Windows printers is similar and uses the smbprint filter:

  winpr:\
          :sd=/var/spool/lpd/winpr:\
          :mx#0:\
          :sh:\
          :if=/usr/bin/smbprint: