You can use the PyMuPDF module with Python to extract images from a PDF file. You can install PyMuPDF using the pip package manager with the command pip install PyMuPDF . You can determine if it is already installed with the command pip list | grep PyMuPDF or pip freeze | grep PyMuPDF.

# pip list | grep PyMuPDF
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Ple
ase upgrade your Python as Python 2.7 won't be maintained after that date. A fut
ure version of pip will drop support for Python 2.7.
PyMuPDF                          1.14.13
# pip freeze | grep PyMuPDF
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Ple
ase upgrade your Python as Python 2.7 won't be maintained after that date. A fut
ure version of pip will drop support for Python 2.7.
PyMuPDF==1.14.13
#

The code for the file is in extract-PDF-image.py.

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[/languages/python] permanent link

When I attempted to copy an Outlook .ost file to an external USB flash drive, I saw the message below:

I didn't have Outlook open and didn't know what other process was using the file. One way to find out which process has a lock on a file is to use the Process Explorer utility provided by Microsoft. The program is free and you don't need administrator rights on a system to use it. To determine a process that is using the file, you can hit the Ctrl and F keys simultaneously, which will bring up a search box where you can type the name of the relevant file. When you click on the Search button, you should be able to see the name of the process that has a lock on the file as well as the process ID (PID) for that process. E.g., in this case I could see that lync.exe was using the file.

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[/os/windows/processes] permanent link

I upgraded a MacBook Pro laptop that was running OS X El Capitan to macOS High Sierra (10.13.6) this week. The laptop was running Apache webserver software. After the upgrade, the system wasn't listening on port 80 for HTTP connections, but I was able to start it listening again with sudo apachectl start.

$ netstat -a | grep http | grep LISTEN
$ sudo apachectl start
Enter PIN for 'Certificate For PIV Authentication (JAMES CAMERON)': 
$ netstat -a | grep http | grep LISTEN
tcp46      0      0  *.http                 *.*                    LISTEN     
$

I was then able to access the default webpage at http://localhost which displayed the page contained in index.html.en file in the DocumentRoot directory at /Library/WebServer/Documents, but whenever I attempted to display pages I had created elsewhere, I kept getting a "404 Not Found" page indicating the requested URL was not found on the server. When I checked /private/etc/apache2/extra/httpd-vhosts.conf, I found it had a April 4, 2018 timestamp, but no longer had the virtual host information I had previously put in the file.

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[/os/macOS] permanent link

If you need to rip a CD from a command-line interface (CLI) on a CentOS Linux system, cdparanoia will allow you to do so. The cdparanoia CD ripper program will allow you to produce Waveform Audio File Format, i.e., .WAV, files from the tracks on a CD. You can use the yum package management software to install the software with by issuing the command yum install cdparanoia from the root account.

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[/os/unix/linux/centos/music] permanent link

Sometimes you may find that a software package that you would like to use on a CentOS Linux system is unavailable from the default software repositories, aka "repos." In such cases adding alternative repos, such as Extra Packages for Enterprise Linux (EPEL) or RPM Fusion may allow you to locate the desired package. E.g., the VLC media player is available in the RPM Fusion repository, but not the default ones nor in EPEL. RPM Fusion has two separate software repositories, one that contains free and open-source software (FOSS) and another named "nonfree". Packages in the "nonfree" repository still won't cost you anything, but there may be restrictions on the use of the software, e.g., you may be forbidden from using the software for commercial use. The RPM Fusion site defines the nonfree repo as being 'for redistributable software that is not Open Source Software (as defined by the Fedora Licensing Guidelines); this includes software with publicly available source-code that has "no commercial use"-like restrictions.'

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[/os/unix/linux/centos] permanent link

I wanted to try the Pale Moon web browser, which is free and open-source software (FOSS) on a CentOS 7 Linux system, but when I tried installing it with yum, the package was not found.

# yum install palemoon
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
 * base: centos-distro.1gservers.com
 * epel: archive.linux.duke.edu
 * extras: centos.host-engine.com
 * updates: centos.den.host-engine.com
No package palemoon available.
Error: Nothing to do
#

I was able to resolve the problem, by adding the Pale Moon repository.

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[/network/web/browser] permanent link

If you want to monitor file changes in a directory on an Apple OS X/macOS system, one way to do so is using fswatch, a cross-platform file change monitor. The utility will allow you to monitor which files in the directory have been changed, though it doesn't report on the particular changes made to the content of the files. You can track the addition and deletion of files or whether files in the monitored directory are modified. On a Mac OS X system, you can install the software using the Homebrew package management system - see Installing Homebrew on Mac OS X for instructions on installing the software. Once Homebrew is installed, you can install fswatch using the command brew install fswatch in a Terminal window, which provides a command-line interface (CLI). The program will be installed in /usr/local/bin. Once it is installed, you can view help information by typing fswatch -h at a Terminal window shell prompt.

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[/os/os-x/homebrew] permanent link

I have a number of log directories where I store log files where the directory name is the current year. On the last day of the old year, I want to create new directories named for the upcoming year. I use the following Bash script to create those directories. Since I have several email log directories, I use a for loop to create a directory named after the upcoming year in each one.

#!/bin/bash
#
# Create a new directory corresponding to the upcoming year on December 31 of
# every year

newyear=$(date --date=tomorrow +%Y)
echo $newyear

# Apache logs

# Check on whether the directory for the current year exists and, if it doesn't,
# create it.
if [ ! -d /home/jdoe/www/logs/apache/"$newyear" ]; then
   mkdir /home/jdoe/www/logs/apache/"$newyear"
   chown apache /home/jdoe/www/logs/apache/"$newyear"
   chgrp apache /home/jdoe/www/logs/apache/"$newyear"
fi

# Email logs 

# Create an array holding the names of the 4 directories within which
# subdirectories will be created using the name of the new year. E.g.,
# /home/jdoe/www/logs/mail/sendmail_stats/2019

logdirs=( "dnsbl_count" "sendmail_stats" "smlogstats" "smreject"  )

for i in "${logdirs[@]}"
do :
   # Check on whether the directory for the current year exists and, if it 
   # doesn't, create it.
   if [ ! -d /home/jdoe/www/logs/mail/$i/"$newyear" ]; then
      mkdir /home/jdoe/www/logs/mail/$i/"$newyear"
      chown jdoe /home/jdoe/www/logs/mail/$i/"$newyear"
      chgrp jdoe /home/jdoe/www/logs/mail/$i/"$newyear"
   fi
done

I then have a crontab entry containing the following line that will result in the Bash script above, named end-of-year-dirs, being run at 7;00 AM on December 31 of each year.

0 7 31 DEC * /root/bin/end-of-year-dirs

Related articles:

1. Loop through an array in Bash
2. CRONTAB
3. crontab -e
4. smlogstats

[/os/unix/bash] permanent link

Information on the fans contained within a Gateway 920 PC. There are three fans in the system: a CPU fan, a case fan, and a fan attached to the power supply unit (PSU).

CPU Fan

Manufacturer: AVC
Model: C6025B12L
Power Connection: 3-Pin
Fan Size: 60mm
DC 12V 0.12A
Ball Bearing

Manufacturer: Antec
Fan Size: 80mm

Power Supply Manufacturer: Newton Power Limited
Power Supply Model: NPS-250HB A
Output: 250W Max.
Fan Size: 90mm

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[/hardware/fans] permanent link

1. Click on Applications at the top, left-hand corner of the screen and select System Tools.

2. Then select Settings.

3. Select Online Accounts from Settings.

4. In the online accounts list, click on Google.

5. You will then be presented with a Google Account sign in window where you can provide your Google credentials, e.g., an email address or phone number.

6. After you hit enter and log in, you will then be asked to accede to allowing GNOME to access your Google account, which will allow GNOME the following access:

   • Read, compose, send, and permanently delete all your email from Gmail
   • See, edit, create, and delete all your Google Drive files
   • See, edit, create, and delete any of your Google Drive documents
   • Manage your printers
   • See, edit, download, and permanently delete your contacts
   • See, edit, create, and delete your spreadsheets in Google Drive
   • See, edit, share, and permanently delete all the calendars you can access using Google Calendar
   • Manage your photos and videos
   • View and send chat messages
   • Create, edit, organize, and delete all your tasks

     You can scroll down to the bottom of the list and click on the Allow button to accept the agreement. You can then close the Google Account window by clicking on the "X" at the top, right-hand side of the window.

If you then click on Applications and Files, you should see your Google account listed at the left side of the window. You can then copy files to and from your Google Drive folders to the local host or access files already stored in Google Drive.

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[/network/web/services/google/drive] permanent link