[SOLVED] re. how do I automate printing a print file to a network printer.

paul1945 · 08-09-2012, 02:40 AM

I am running some old legacy software (written in xBase) under DosBox in Ubuntu 12.04, but of course DosBox has no printing capability.
I have set up the program in question to produce a ".prn" file that contains all the required pcl-6 codes for the printer together with the text.
So far I have written the following shell script:

#!/bin/bash
lpr -P HP-LaserJet-m2727-MFP -l -r -o raw /home/paul/dosdrive/*.PRN

which works fine; but this needs to be executed each time.
I am almost sure that there must be a way to tell Ubuntu to poll for a print file in a given directory and print this automatically, but I am not sure of how to do this.
I have brought this foward on another Forum, but no luck so far.

michaelk · 08-09-2012, 08:12 AM

Welcome to LinuxQuestions.

One suggestion would be to use inotify (install the inotify-tools package) to monitor the directory where the prn files are located. A script using inotifywait or inotifywatch can be run to detect when a prn file is created and then print it.

paul1945 · 08-09-2012, 08:04 PM

Thanks for that, I'd like to give that a try. Found the package for Ubuntu and have installed same.
I am rather new at this (a whole month of Linux use). So could you give me some hints as to the type of script (and file types) required?

michaelk · 08-09-2012, 09:37 PM

Untested code...

Code:

#!/bin/sh
while inotifywait -m -e close_write /home/paul/dosdrive/; do
  lpr -P HP-LaserJet-m2727-MFP -l -r -o raw /home/paul/dosdrive/*.PRN
  rm *.PRN  
done

paul1945 · 08-10-2012, 12:44 AM

Hello michaelk, thanks for that; unfortunately it comes up with "bad interpreter: no such file or directory". I tried "#!/bin/bash" and "#!/bin/dash" but to no avail (would not have a clue what I was doing).
The problem may be due to the location of inotifywatch and inotifywait, which are in the "/usr/bin" directory, and it may expect these in the "/bin" directory.
Any solution to this?

paul1945 · 08-14-2012, 01:00 AM

Tried a uninstall and reinstall of the inotify package but to no avail. Any idea as to what may be going wrong? Anyone? Thanks, Paul.

michaelk · 08-14-2012, 10:34 AM

The path environment might not include /usr/bin. Its been awhile since I've played with inotify so hopefully this will work for you. Add a line to the /etc/rc.local and it will start at boot up. i.e.
/path/to/prndosfiles_script & (The & puts the script in the background)

Code:

#!/bin/sh
/usr/bin/inotifywait -e close_write -mrq /home/paul/dosdrive | while read line; do
   set -- "$line"
   IFS=" "; declare -a Array=($*)
   FILE="${Array[2]}"
   FILENAME=${FILE%.*}
   FILEEXT=${FILE##*.}
   IFS=""
   if [ "$FILEEXT" == "PRN" ];
   then
      lpr -P HP-LaserJet-m2727-MFP -l -r -o raw /home/paul/dosdrive/$FILE
   fi      
done

paul1945 · 08-14-2012, 09:43 PM

Sorry to be a pain, but unfortunately things just don't work.
I have used a copy of the exact code you provided into a shell script called "print_prn.sh"
But if I execute the print_prn.sh file from the terminal window I get this:

bash: /home/paul/print_prn.sh: /bin/sh^M: bad interpreter: No such file or directory

If I make a link and execute it from this, this error comes up:

Details: Failed to execute child process "/home/paul/bin/print_prn.sh" (no such file or directory)

I have also changed the file "/usr/rc.local" as follows:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
/home/paul/bin/print_prn.sh &
exit 0

I get no errors on boot, but it does not pick up the prn file either. Paul.

michaelk · 08-14-2012, 10:11 PM

Did you use a linux or windows text editor to create the script? The ^M typically indicates a DOS end of line character which will cause errors.
If you did use a windows text editor there are many ways to convert the file.

http://kb.iu.edu/data/acux.html

paul1945 · 08-14-2012, 11:37 PM

Hello michaelk, Downloaded and installed dos2unix (together with a whole lot of related stuff apparently), converted the file and it no longer came up with errors, but did not work.
Tried changing the first line to "#!/bin/bash" and it now works a treat, thank you for your help.
I am not sure what the problem was, but obviously Ubuntu 12.04 does something that is not standard.
On investigation I found "/bin/sh" is only present as a link that points to "dash". "Dash" is supposed to be a command interpreter, but maybe it does odd things and is not compatible.