Parallel Document Conversion ODT > PDF Libreoffice

Question

I am converting hundreds of ODT files to PDF files, and it takes a long time doing one after the other. I have a CPU with multiple cores. Is it possible to use bash or python to write a script to do these in parallel? Is there a way to parallelize (not sure if I'm using the right word) batch document conversion using libreoffice from the command line? I have been doing it in python/bash calling the following commands:

libreoffice --headless --convert-to pdf *appsmergeme.odt

OR

subprocess.call(str('cd $HOME; libreoffice --headless --convert-to pdf *appsmergeme.odt'), shell=True);

Thank you!

Tim

Answer 1

You can run libreoffice as a daemon/service. Please check the following link, maybe it helps you too: Daemonize the LibreOffice service

Other posibility is to use unoconv. "unoconv is a command line utility that can convert any file format that OpenOffice can import, to any file format that OpenOffice is capable of exporting."

Answer 2

Since the author already introduced Python as a valid answer:

import subprocess
import os, glob
from multiprocessing.dummy import Pool    # wrapper around the threading module

def worker(fname, dstdir=os.path.expanduser("~")):
    subprocess.call(["libreoffice", "--headless", "--convert-to", "pdf", fname],
                    cwd=dstdir)

pool = Pool()
pool.map(worker, glob.iglob(
        os.path.join(os.path.expanduser("~"), "*appsmergeme.odt")
    ))

Using a thread pool instead of a process pool by multiprocessing.dummy is sufficient because new processes for real parallelism are spawn by subprocess.call() anyway.

We can set the command as well as the current working directory cwd directly. No need to load a shell for each file for just doing that. Furthermore, os.path enables cross-platform interoperability.

Answer 3

this thread or answer is old. I tested libreoffice 4.4, I can confirm I can run libreoffice concurrently. see my script.

for odt in test*odt ; do
echo $odt
soffice --headless --convert-to pdf $odt & 
ps -ef|grep ffice 
done