GNU/Linux

Bulk convert PNG images to JPG / JPEG

 in Bash / GNU/Linux  tagged bash / Bulk / convert / GNU/Linux / imagemagick / images by 
for i in *.png ; do convert "$i" "${i%.*}.jpg" ; done

The command “for i in .png ; do convert “$i” “${i%.}.jpg” ; done” is a Bash script that converts all PNG files in the current directory to JPEG files.

Let’s break down this command:

  • “for i in *.png ;” is a loop that iterates over each PNG file in the current directory.
  • “$i” is the name of the current PNG file being processed.
  • “convert” is a command-line tool that is part of the ImageMagick software suite. It is used for image conversion, resizing, and manipulation.
  • “${i%.}.jpg” is the new filename that the PNG file will be converted to. The “${i%.}” syntax is used to remove the file extension from the original PNG file name, leaving just the base filename, which is then followed by “.jpg” to indicate that the new file should be a JPEG file.

In summary, this command converts each PNG file in the current directory to a JPEG file with the same base filename. For example, “example.png” would be converted to “example.jpg”. This command can be useful when you have a large number of PNG files that you need to convert to JPEG format quickly and easily.

How to monitor all outgoing requests/connections from your GNU/Linux machine

 in Bash / GNU/Linux  tagged bash / connections / GNU/Linux / netstat / network / server by 
netstat -nputw;

The “netstat” command is a network utility tool used to display information about active network connections, including the protocol used (TCP or UDP), the local and remote addresses and port numbers, and the current state of the connection.

The options used in this command are as follows:

  • “n” displays addresses and port numbers in numerical form rather than converting them to hostnames and service names.
  • “p” shows the process ID (PID) and program name using the connection.
  • “u” displays UDP connections.
  • “t” displays TCP connections.
  • “w” displays raw sockets.
  • “;” separates the command from other commands that may follow.

Therefore, the command netstat -nputw; will display all current network connections on the machine, including the corresponding processes and raw socket connections, in a numerical format without resolving hostnames and service names.

Mount a Windows share on a GNU/Linux server

 in GNU/Linux  tagged cifs / GNU/Linux / mount / share / ubuntu / windows by 
sudo mount -t cifs //$WINDOWS_FILE_SERVER/$SHARED_FOLDER /var/www/bytefreaks.net/shared/ -o username=remoteUser,password='123abc',domain=bytefreaks.net,file_mode=0777,dir_mode=0777;

The command sudo mount -t cifs //$WINDOWS_FILE_SERVER/$SHARED_FOLDER /var/www/bytefreaks.net/shared/ -o username=remoteUser,password='123abc',domain=bytefreaks.net,file_mode=0777,dir_mode=0777 is used to mount a shared folder from a Windows file server onto a Linux system.

To break down the command further, here is a detailed explanation of each component:

sudo – this command is used to run the following command as a superuser or root. It is required in this instance as mounting requires administrative privileges.

mount – the mount command is used to mount a file system onto a directory in the Linux file system hierarchy.

-t cifs – this option specifies the type of file system that is being mounted. In this case, it is the Common Internet File System (CIFS), which is used for file sharing between Windows and Linux systems.

//$WINDOWS_FILE_SERVER/$SHARED_FOLDER – this is the network path to the shared folder on the Windows file server. The $WINDOWS_FILE_SERVER and $SHARED_FOLDER are placeholders for the actual Windows file server name and shared folder name, respectively.

/var/www/bytefreaks.net/shared/ – this is the mount point, or the location in the Linux file system hierarchy where the shared folder will be mounted.

-o username=remoteUser,password='123abc',domain=bytefreaks.net,file_mode=0777,dir_mode=0777 – these are the mount options that are specified when mounting the shared folder.

The username option specifies the username of the remote user that has access to the shared folder. In this case, the remote user is named remoteUser.

The password option specifies the password for the remote user.

The domain option specifies the domain or workgroup that the Windows file server belongs to. In this case, the domain is bytefreaks.net.

The file_mode and dir_mode options specify the permissions that should be set on the files and directories within the mounted shared folder. In this case, both are set to 0777, which means that all users have full read, write, and execute permissions on all files and directories within the mounted shared folder.

In summary, the sudo mount -t cifs //$WINDOWS_FILE_SERVER/$SHARED_FOLDER /var/www/bytefreaks.net/shared/ -o username=remoteUser,password='123abc',domain=bytefreaks.net,file_mode=0777,dir_mode=0777 command is used to mount a shared folder from a Windows file server onto a Linux system with the specified mount options.

How to empty the gnome tracker3 cache?

 in Bash / GNU/Linux  tagged bash / clear cache / daemon / free space / gnome / GNU/Linux / tracker3 / ubuntu by

To empty the cache of gnome tracker3, you can follow the steps below:

Open a terminal window by pressing Ctrl + Alt + T.

Type the following command to stop the tracker daemon:

tracker3 daemon -t;

Type the following command to clear the tracker database:

tracker reset --filesystem;

This command will remove all indexed data from the tracker and clear its cache. (Remove filesystem indexer database)

Restart the tracker daemon by typing the following command:

tracker daemon -s ;

This will start the tracker daemon again, and it will begin to rebuild its database and cache.

After following these steps, the cache of gnome tracker3 will be emptied.

Execution example:

$ tracker3 daemon -t
Found 1 PID…
  Killed process 13705 — “tracker-miner-fs-3”
$ tracker3 reset --filesystem
Found 1 PID…
  Killed process 13705 — “tracker-miner-fs-3”
$ tracker3 daemon -s
Starting miners…
  ✓ File System