The problem

Convert .doc, .odt, .docx files to .pdf, or another combination (i.e. .docx to .odt)
under PHP.

To solve this problem we’ll install Unoconv,
LibreOffice command tools and build a PHP Class.

Installing

Unoconv is Python tool that uses LibreOffice libs (pyuno).

Instaling LibreOffice command line tools

On a server you’re not required to make a full install of LibreOffice,
just command line and converters that you find on core.

For Ubuntu/Debian:

apt-get install openjdk-6-jdk libreoffice-core libreoffice-common libreoffice-writer python-uno

Important:

Installing libreoffice-writer gives you support to convert TEXT documents.
To convert other formats (spreadsheets, presentations, images, etc), install the related LibreOffice package.

For images, consider lighter and well-known tools such ImageMagick;

For converting PDF to Text, consider PDF to Text – you can find it in Poppler-Utils package.

Installing o Unoconv

Installing libreoffice-writer gives you support to convert TEXT documents.
To convert other formats (spreadsheets, presentations, images, etc), install the related LibreOffice package.

For images, consider lighter and well-known tools such ImageMagick;

For converting PDF to Text, consider PDF to Text – you can find it in Poppler-Utils package.

Installing o Unoconv

As root:

cd /tmp
git clone https://github.com/dagwieers/unoconv
cd unoconv/
make install
cd ../
rm -rf unoconv/
unoconv --listener &

So you’ve started LibreOffice/OpenOffice as a service running on a local port,
and you can check with ps aux | grep soffice.

Some warnings:

• Unlike you can convert only with a LibreOffice/OpenOffice install, using the
  service and unoconv is better for mass intensive operations, because you
  reuse an instance always in memory.

• unoconv package is already in Debian repositories but that’s an old version.

Showing support formats

unoconv --show

Creating a Deamon

To demonize unoconv (better for server mode), create a file /etc/init.d/unoconvd with the following content:

( Source )

#!/bin/sh
### BEGIN INIT INFO
# Provides: unoconvd
# Required-Start: $network
# Required-Stop: $network
# Default-Start: 2 3 5
# Default-Stop:
# Description: unoconvd - Converting documents to PDF by unoconv
### END INIT INFO
case "$1" in
    start)
        /usr/bin/unoconv --listener &
        ;;
    stop)
        killall soffice.bin
        ;;
    restart)
        killall soffice.bin
        sleep 1
        /usr/bin/unoconv --listener &
        ;;
esac

The adjust permissions, put on boot and run the daemon:

chmod 755 /etc/init.d/unoconvd
update-rc.d  unoconvd defaults
service unoconvd start

Basic use

It doesn’t matter if you’ve started unoconv manualy or deamonized, you can
use as bellow to convert files:

unoconv --format pdf --output /OUTPUT_DIR/ file.odt

That will convert the file.odt to file.pdf on the informed output directory.

PHP Class

A simple PHP wrapper could be as bellow:

<?php

namespace Unoconv;

/**
 * Unoconv class wrapper
 *
 * @author Rafael Goulart <rafaelgou@gmail.com>
 * @see http://tech.rgou.net/
 */
class Unoconv {

    /**
     * Basic converter method
     * 
     * @param string $originFilePath Origin File Path
     * @param string $toFormat       Format to export To
     * @param string $outputDirPath  Output directory path
     */
    public static function convert($originFilePath, $outputDirPath, $toFormat)
    {
        $command = 'unoconv --format %s --output %s %s';
        $command = sprintf($command, $toFormat, $outputDirPath, $originFilePath);
        system($command, $output);

        return $output;
    }

    /**
     * Convert to PDF
     * 
     * @param string $originFilePath Origin File Path
     * @param string $outputDirPath  Output directory path
     */
    public static function convertToPdf($originFilePath, $outputDirPath)
    {
        return self::convert($originFilePath, $outputDirPath, 'pdf');
    }

    /**
     * Convert to TXT
     * 
     * @param string $originFilePath Origin File Path
     * @param string $outputDirPath  Output directory path
     */
    public static function convertToTxt($originFilePath, $outputDirPath)
    {
        return self::convert($originFilePath, $outputDirPath, 'txt');
    }

}

Sample use:

<?php
/**
 * Sample use of Unoconv class
 *  
 */
require 'Unoconv.php';

use Unoconv\Unoconv;

// Converting to PDF
$originFilePath = 'test.odt';
$outputDirPath  = './';
Unoconv::convertToPdf($originFilePath, $outputDirPath);

// Converting to DOCX
$originFilePath = 'test.odt';
$outputDirPath  = './';
Unoconv::convert($originFilePath, $outputDirPath, 'docx');