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

Answer 1

I've written a program in golang to batch convert thousands of doc/xls files.

• define the "root" variable value to the path of your documents to convert
• already converted documents to pdf are skipped (if not, comment the check condition in the visit() function)
• here I'm using 4 threads (I have an Intel i3 with 4 cores). You can modify the value in the main() function

Sometimes it can happen that Libreoffice doesn't convert some files, so you should open it and convert them to PDF manually. Luckily, they were only 10 out of my 16.000 documents to convert.

package main

import (
    "os/exec"
    "sync"
    "path/filepath"
    "os"
    "fmt"
    "strings"
)

// root dir of your documents to convert
root := "/.../conversion-from-office/"

var tasks = make(chan *exec.Cmd, 64)

func visit(path string, f os.FileInfo, err error) error {
    if (f.IsDir()) {
        // fmt.Printf("Entering %s\n", path)
    } else {
        ext := filepath.Ext(path)
        if (strings.ToLower (ext) == "pdf") {
        } else {


            outfile := path[0:len(path)-len(ext)] + ".pdf"

            if _, err := os.Stat(outfile); os.IsNotExist(err) {

                fmt.Printf("Converting %s\n", path)

                outdir := filepath.Dir(path)
                tasks <- exec.Command("soffice", "--headless", "--convert-to", "pdf", path, "--outdir", outdir)
            }
        }
    }
    return nil
} 


func main() {
    // spawn four worker goroutines
    var wg sync.WaitGroup

    // the  ...; i < 4;... indicates that I'm using 4 threads
    for i := 0; i < 4; i++ {
        wg.Add(1)
        go func() {
            for cmd := range tasks {
                cmd.Run()
            }
            wg.Done()
        }()
    }


    err := filepath.Walk(root, visit)
    fmt.Printf("filepath.Walk() returned %v\n", err)

    close(tasks)

    // wait for the workers to finish
    wg.Wait()
}