Release Notes - Duplex 0.2.1 - 11/22/2012
Maintenance Release - with minor bug fixes
Switched from using zenity to yad for gui interface.
Duplex (two-sided) printing saves paper, money, trees, and space. Several other utilities are available
which provide this functionality, but most require the user to select options in a popup window and are
prone to user error. No utility I am aware of will (gracefully) allow a user to print multiple duplex print
jobs in a batch.
The duplex package is a set of shell scripts for duplex printing. The nature of shell scripts makes them
relatively easy to extend and modify. I have tried to use string constants and put system dependencies in
functions to further facilitate this.
Once the package (tarball) is unpacked, the scripts are ready to use. Just put them in a directory that is
in your PATH (e.g. $HOME/bin) so your shell can find them.
Several of the scripts use enscript to convert text files to postscript.
For this to work correctly, add the following to the file .enscriptrc in your home directory.
If this file does not exist, create it.
# Defaults for enscript (used by duplexpr package)
where "<path>" is the full path of the directory where you installed dplx.
For example, if you installed dplx in /home/joe/bin then it would be:
You may also need to set the default paper type as in:
(Replace Letterdj with the page definition for the paper you use.)
All of the scripts are optional. Use those that fit your work style.
The script names are intended to be unique (should not replace any existing commands on your system), but be
sure to verify this for yourself BEFORE installing them.
Brief synopsis of the scripts (see duplex.txt for details):
dplx - Prints one two-sided print job by setting up the parameters and calling duplex
duplex - Prints one two-sided print job
mpr - Multiple print duplex jobs - one complete job (both sides) at a time using dplx
mprb - Multiple print batch duplex jobs - prints the odd pages of all jobs in one pass
and all the even pages in the other pass
dprint - Prints one text job two-sided using some settings such as margins, wordwrap, and, optionally, font
dprintm - Prints one text job two-sided with a mono-spaced font (for structured text e.g. source code)
rmpq - Remove files from the print queue
kmprb - gui to preview, print, and remove print files
krmpq - gui version of rmpq
After installation, the file, Test_File.ps should be printed using dplx. This four page (two sheet) document
will show you clearly whether duplex printing is working on your system.
A detailed description of how this file printed along with the value of the -ps parameter should be included in any bug reports
related to printed output page issues.
If the default does not work, try adding -ps 1 as the first parameter and see if that fixes it for
your printer. If it does, you can modify the default value in the scripts.
I have several notebook computers running kubuntu (currently kubuntu oneiric and precise) with kde4.
I have a couple of laserjets and one Photosmart Inkjet printer
and three print queues running under CUPS. The Duplex package works well in this setup. I
almost feel like I have a new, better printer now that I don't have to flip the output of each job and watch
out not to reinsert the last page of odd page count jobs. I wanted this to work as easily as it does under
Windows. And now, with mprb/kmprb, it works a lot better than Windows!
Many computer systems are far more complex than mine. I look forward to others testing the package on
systems with networked printers, multiple printers and queues, and shared printers. I think it should work
on all of them (as long as no one else is printing to a shared printer at the same time as one of these
scripts is printing to it!), but there is no substitute for testing.
The code has a couple of system dependencies and I don't know how universally applicable they are.
The function ps_page_ct() relies on whatever creates the postscript files to be printed (or enscript, if the
files to be printed are not already postscript) to put the postscript %%Pages: nnn line into the file near
the beginning or end of the file. So far, it's been in one or the other place in all files I've printed
except those printed by Opera. For those, the script counts the number of showpage commands. This method is
not guaranteed to work because one showpage command could be in a function called multiple times.
I have recently seen a document in PostScript 1.6. My page counting algorithms do not know how to handle this format yet (and fail with an error message.)
A similar situation exists for pdf_page_ct() with pdf files. It searches heuristically for the largest page count.
To get the definitive answer, the script/function would have to use ghostscript to render the complete print file
just to accurately count the number of pages generated. That would be way too resource/time intensive to justify on
current end user computers.
The function lp_queue_id() relies on the output of the lp command to contain the queue-job_number in the
fourth word of the line. This is too hard coded for my taste, but I don't know another way to do it.
Although yad (the tool that provides the gui interfaces) does depend on GTK, I think it should run fine on other window managers and desktops. If
not, a console-only version of the scripts would be easy to write, but it wouldn't be quite as user friendly.
The code is written for the way an HP Deskjet printer (page handling strategy 1) or an HP Laserjet P1006 printer (page handling strategy 2) handles paper.
It also gets it perfectly for my HP Photosmart C4480 (page handling strategy 1). The Laserjets now print all the pages correctly using page handling strategy 2.
To get this to work for all printers may requre a rewrite because one size doesn't fit all.
It will probably require at least four (maybe 16) printing strategies to cover most printers and for now, there are only two.
(But Hey, that's twice as many as the previous version.)
If another printer works differently, all the same components of the code should still work with some
rearranging of the sequence. The Deskjet prints such that the output stacks printed face up with the most
recent page on top. To print the reverse side, all pages are manually removed, rotated 180 degrees
horizontally and reinserted into the in paper tray. The Laserjets print such that the output stacks printed
face down with the most recent page on the top. To print the reverse side, all pages are manually removed, rotated 180 degrees
horizontally and reinserted into the in paper tray.
The way I use the system is: As I'm browsing the Internet or doing other tasks, I use "Print to File" for most
things and put them all in one directory ($HOME/pq) with file names like 01, 02, 03, .... (File names ending in .ps or .pdf now work fine as well.) That keeps the print jobs in
the same order I generated them in. Then, when I'm ready, I just cd to that directory, do an mprb -I * to
see how much I'm going to print (and if I need to modify the print order to put some small jobs ahead of
large ones, etc.). Then, I usually let it go ahead and print the whole queue. When it's done and checked, I
use rmpq to delete the files in the print queue. When I have a lot to print, I just use shell regular expressions to
specify which files to print and then rmpq. E.g. mprb -I 0* or mprb -I 0 .
For anyone interested, I aso have an AutoKey macro available (not included in the duplex package) which is tied to ctrl-p
for Firefox and Thunderbird. It automagically selects print to file and fills in the next available print queue file name.
Then it ends so that other print dialog options can still be selected.
Now that I have kmprb, I have added an icon for it to my panel (task bar). Once I have generated the print
files as above, usually, I just click on the panel icon and let kmprb do the rest. That way I can stay focused
on what I am doing because I don't need to navigate through any menus or switch to a console window on another
desktop. I also have an icon for pqnext (new, included) in my panel so I can get the next print queue file name
for manual use with applications other than Firefox or Thunderbird. These icons are not added to the panel by installing the duplex package. It must be done manually.
Sometimes, I do an mprb -i * first. If there are any one-page print jobs, I print them all directly with one lp command (very fast)
and then delete them. Then, I print any remaining jobs with mprb. This is especially useful if you use print strategy 2 which will print
all one page jobs as blank pages during pass one because it prints even pages first and there aren't any.
In real life, printers run out of ink, occasionally jam, and feed multiple pages at one time. To handle this eventuality, mprb only prints
one job at a time during pass two (where jams, and especially multi-feeds are more likely) so it can be killed without having to remove
a number of jobs from the system print queue with lprm. mprb also has a -pass2 option so that after a jam,
any jobs which still have good pass one output (all sheets with just one side printed) may be reinserted into the printer to print
just pass 2 (the other side of all the sheets). Now, with faster processors and printers and big print buffers, this doesn't work as nicely as it used to,
but if this is a problem, it would be easy to add an additional delay between pass 2 print jobs.
I am also including a few gui apps. They work, but are hard
coded to expect the print queue to be in $HOME/pq.
kmprb is a gui which does it all. It displays all the files in the print queue along with the number of pages
each will generate.
Next, it allows you to select which files to print and prints them.
Finally, it allows you to select which files to delete. (Presumably, they are not needed any longer once they
have been successfully printed.)
krmpq allows you to select those print files you want to delete once they have been printed.
pqnext pops up an information dialog with the number of the next available print queue file name along with a
count of jobs and and pages in the print queue. This is useful for manually specifying the file name in applications.