howto.coytis.me

Linux commands

4 min read

What like you were never a beginner? Fuck you

CD

Same as windows

Go forward

cd <filename>

Go somewhere specific

cd /path/to/file

Go Back

  cd  ..

ls

List contents of a folder

Example:

rick@media-server:/mnt/media$ ls
downloads  jellyfin-cache  lost+found  movies  tv

Search:

ls | grep "tv"

The | (pipe) takes the output of whatever’s on the left and feeds it in as input to whatever’s on the right, instead of printing it to screen. So ls lists everything, then grep "tv" filters that list down to just lines containing “tv”.

Search recursively through subfolders too:

find /path/to/folder -iname "*tv*"

-iname = case-insensitive name match (drop the i for case-sensitive).

Modifiers:

  • -i - Make the result Case insensitive
  • -lh - Gives more information

Fun Fact: ‘GREP’ stands for Global Regular Expression Print

rm

Delete Stuff

For files:

rm /path/to/file

For folders (recursive):

rm -rf /path/to/folder

Modifiers:

  • -r removes folders recursively,
  • -f skips the “are you sure” prompts. If it’s just a single file (not a folder) you can drop the flags and just do rm filename.
  • -i confirms beforehand

mkdir

Makes a folder

mkdir /path/to/folder

mv

Renames a file (also used to move it somewhere else)

Rename in place:

mv oldname.ext newname.ext

Move to another folder:

mv /path/to/file /new/path/

File size

How big is this thing

Single file:

ls -lh filename

Whole folder (total size, human readable):

du -sh /path/to/folder

Every file and folder inside, biggest first:

du -ah /path/to/folder | sort -rh | head -50
  • du -ah - disk usage, all files (not just folders), human-readable sizes (K/M/G instead of raw bytes)
  • sort -rh - sort by size, reverse (biggest first), h tells sort to read “1.2G” as a size instead of just text
  • head -50 - only show the first 50 lines of the sorted list. Bump the number or drop it to see more.

Just the top level, don’t dig into every subfolder (way less noisy on a big directory):

du -h --max-depth=1 /path/to/folder | sort -rh

Just the biggest individual files, skip folder totals entirely:

find /path/to/folder -type f -printf '%s %p\n' | sort -rn | head -30
  • find -type f - only match files, not folders
  • -printf '%s %p\n' - print size in bytes (%s) then the path (%p) for each file
  • sort -rn - sort numerically, reverse (biggest first) - plain numbers here so it’s -n not -h

If it’s chugging on a big/busy folder and you don’t want to sit there watching it:

du -ah /path/to/folder > ~/sizes.txt 2>&1 &

The trailing & backgrounds the job so you get your terminal back. Check on it later with cat ~/sizes.txt or wc -l ~/sizes.txt.

Go easy on disk I/O while it runs (handy if something else is actively downloading/writing):

ionice -c3 nice -n19 du -ah /path/to/folder | sort -rh

ionice -c3 = lowest disk priority, nice -n19 = lowest CPU priority. Won’t fight other processes for resources.

Reboot

Guess… Not even sure if you need the sudo

sudo reboot

nano

Edits text files

sudo nano /path/to/folder

cat

Reads text files

sudo cat /path/to/folder

Batch rename old scene-release rips to SxxExx

For those ancient torrent releases named like futurama.101-lol.avi (season digit + 2-digit episode, no SxxExx anywhere) so Sonarr can actually recognise them after a manual move/rescan.

cd into the folder the files are sitting in first, then swap the season number (1 below) wherever it appears - glob, sed pattern, and the output S01:

for f in futurama.1*-lol.avi; do
  ep=$(echo "$f" | sed -E 's/futurama\.1([0-9]{2})-lol\.avi/\1/')
  mv "$f" "Futurama - S01E${ep}.avi"
done

Used this on Futurama S1/S2 after Sonarr got stuck importing them - renamed, then Rescan Series in Sonarr picked them straight up. If Sonarr still says “no file to import” after that, check Activity > Queue for a stuck entry still pointing at the old download folder and remove it from there.

To look at later

find . -maxdepth 2 -iname "dragon.ball.z.s0*" -exec rm -rf {} +

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