General Commands

find / -iname <nombreabuscar>: Search in the root of the file system
tar -xzf *.tar.gz/zip: Extract a .zip or .tar.gz
tar -czf compressed_archive.tar.gz *: Create a compressed archive out of all the files in the current directory
ip r | grep default: get gateway ip
find . -name '*.srt' -delete: Find and delete recursively all .srt files in the current directory
fc-list : family style: List available fonts.
grep -rl <string>: List files with a given string, recursively.
cat input.txt | tr "\n" " " | rg --pcre2 "\b(\w+)\s+\1\b": Print out repeated consecutive words.
inxi -F: Display system information
locale: Get locale-specific information. For example:

LANG=en_US.UTF-8
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME=es_CL.UTF-8
LC_ADDRESS=es_CL.UTF-8
LC_TELEPHONE=es_CL.UTF-8
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION=es_CL.UTF-8
LC_ALL=

Use localectl set-locale to change any of the variables listed above. For example:

sudo localectl set-locale LANG=en_US.UTF-8

Disks

du -chs --exclude="*.txt" .: Report file space usage in the current directory, excluding .txt files
df: Report file system disk space usage.
lsblk: list information about block devices, which typically include hard drives, solid-state drives, and other storage devices, as well as partitions on those devices.
sudo umount /dev/sdX: Unmount device sdX.
sudo dd if=/path/to/iso of=/dev/sdX bs=4M status=progress: write image to the USB drive. if stands for input file, of stands for output file, bs=4M means the block size of 4M and status=progress is to show the progress. After the dd command finishes, run the following command to ensure that all data is written to the USB drive and it’s safe to remove: sync
eject /dev/sdX: Safely eject the USB drive from your system.

Format a USB device

Identify the USB Device. lsblk
Partition the USB Device: Use parted to partition the USB device with the GPT scheme. sudo parted /dev/sdX mklabel gpt
Create a primary partition formatted as FAT32 that spans the entire disk. sudo parted /dev/sdX mkpart primary fat32 1MiB 100%
Format the partition with the FAT32 file system: sudo mkfs.fat -F32 /dev/sdX1

Media

Media Types

xdg-mime query filetype file.pdf: find out the MIME type of my file.pdf. This command will return the MIME type, such as application/pdf.
xdg-mime default evince.desktop application/pdf: Set the default application for the MIME type application/pdf to evince.
xdg-mime query default application/pdf: this command returns the .desktop file of the default application to open pdf files.

Video Editing

Embed subtitles to a video:

  mkvmerge -o output.mkv video.mp4 subtitles.srt

Merge videos:

  # these 2 ways are equivalent
  mkvmerge -o output.mkv video1.mkv + video2.mkv
  mkvmerge -o output.mkv '[' video1.mkv video2.mkv ']'

  mkvmerge -o output.mkv 1.mkv + 2.mkv --generate-chapters when-appending

  # join all the videos together
  mkvmerge -o output.mkv '[' * ']'

Get information of a video:
```
  mkvmerge --identify input.mkv
```

Get audio:

  ffmpeg -i video.mp4 audio.mp3

  mkvmerge -D input.mkv -o audio.aac

  # mkvmerge options:
  -A, --no-audio
  -D, --no-video
  -S, --no-subtitles
  -B, --no-buttons
  -T, --no-track-tags
  --no-chapters
  -M, --no-attachments
  --no-global-tags

Remove audio
```
  mkvmerge -A input.mkv -o output.mkv
```

Add audio to video:

  mkvmerge input.mkv audio.mp3 -o output.mkv

Record audio:

  # Pick the name of a source and use it instead of default
  pactl list sources
  ffmpeg -f pulse -i default output.wav

Trim audio:

  ffmpeg -i input.wav -ss 20 -to 40 -c copy out.wav

Trim a video

  # The output will last 20 seconds
  ffmpeg -ss 00:00:10 -to 00:00:30 -i input.mkv -c copy output.mkv

Split a video

  # Split video into a part of 7 seconds and the rest
  ffmpeg -i input.mkv -to 07 -c copy p1.mkv -ss 07 -c copy p2.mkv

Decrease image resolution

  # Generate an image 20px wide, keeping its aspect ratio
  ffmpeg -i img.jpg -vf scale=20:-1 img-small.jpg

jose-villar