30 interesting commands for the Linux shell – The Diligent Developer
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List of 30 interesting commands and tips for the Linux shell that I have collected over the years.
  • 𝕽𝖚𝖆𝖎𝖉𝖍𝖗𝖎𝖌𝖍@midwest.social
    8·
    4 days ago

    This is a good list.

    There are three kinds of Linux commands:

    • commands I use frequently
    • commands I’ve never seen or don’t know about. There’s almost nothing in standard POSIX that falls in this category, and a lot of OSS that does. E.g., I use to always reach for fuser until I realized it’s not a base install on many distros, so I switched to lsof which is is, and is also both more powerful and harder to use.
    • commands I’ve seen before but use so infrequently I forget they exist, or what they’re called. This is sadly a larger set than I’d like.

    Some of these in this list are the third kind.

  • vort3@lemmy.ml
    7·
    4 days ago

    Looks like the site is down or blocked in my country.

    Could anyone please be so nice and copy paste those commands here?

    • ClusterBomb@lemmy.blahaj.zoneEnglish
      44·
      4 days ago
      1. Supervise command (run every 2s)
      watch "ls -larth"
      1. Kill program using one port
      sudo fuser -k 8000/tcp
      1. Limit memory usage for following commands
      ulimit -Sv 1000       # 1000 KBs = 1 MB
ulimit -Sv unlimited  # Remove limit
      1. Rename selected files using a regular expression
      rename 's/\.bak$/.txt/' *.bak
      1. Get full path of file
      readlink -f file.txt
      1. List contents of tar.gz and extract only one file
      tar tf file.tgz
tar xf file.tgz static
      1. List files by size
      ls -lS
      1. Nice trace route
      mtr google.com
      1. Find files tips
      find . -size 20c             # By file size (20 bytes)
find . -name "*.gz" -delete  # Delete files
find . -exec echo {} \;      # One file by line
./file1
./file2
./file3
find . -exec echo {} \+      # All in the same line
./file1 ./file2 ./file3
      1. Print text ad infinitum
      yes
yes hello
      1. Who is logged in?
      w
      1. Prepend line number
      ls | nl
      1. Grep with Perl like syntax (allows chars like \t)
      grep -P "\t"
      1. Cat backwards (starting from the end)
      tac file
      1. Check permissions of each directory to a file

      It is useful to detect permissions errors, for example when configuring a web server.

      namei -l /path/to/file.txt
      1. Run command every time a file is modified
      while inotifywait -e close_write document.tex
do
    make
done
      1. Copy to clipboard
      cat file.txt | xclip -selection clipboard
      1. Spell and grammar check in Latex
      detex file.tex | diction -bs

      You may need to install the following: sudo apt-get install diction texlive-extra-utils.

      1. Check resources’ usage of command
      /usr/bin/time -v ls
      1. Randomize lines in file
      cat file.txt | sort -R
cat file.txt | sort -R | head  # Pick a random sambple

      # Even better (suggested by xearl in Hacker news):

      shuf file.txt
      1. Keep program running after leaving SSH session

      If the program doesn’t need any interaction:

      nohup ./script.sh &

      If you need to enter some input manually and then want to leave:

      ./script.sh
<Type any input you want>
<Ctrl-Z>          # send process to sleep
jobs -l           # find out the job id
disown -h jobid   # disown job
bg                # continue running in the background

      Of course, you can also use screen or tmux for this purpose.

      1. Run a command for a limited time
      timeout 10s ./script.sh

      # Restart every 30 minutes

      while true; do timeout 30m ./script.sh; done
      1. Combine lines from two sorted files
      comm file1 file2

      Prints these three columns:

      Lines unique to file1.
Lines unique to file2.
Lines both in file1 and file2.

      With options -1, -2, -3, you can remove each of these columns.

      1. Split long file in files with same number of lines
      split -l LINES -d file.txt output_prefix
      1. Flush swap partition

      If a program eats too much memory, the swap can get filled with the rest of the memory and when you go back to normal, everything is slow. Just restart the swap partition to fix it:

      sudo swapoff -a
sudo swapon -a
      1. Fix ext4 file system with problems with its superblock
      sudo fsck.ext4 -f -y /dev/sda1
sudo fsck.ext4 -v /dev/sda1
sudo mke2fs -n /dev/sda1
sudo e2fsck -n <first block number of previous list> /dev/sda1
      1. Create empty file of given size
      fallocate -l 1G test.img
      1. Manipulate PDFs from the command line

      To join, shuffle, select, etc. pdftk is a great tool:

      pdftk *.pdf cat output all.pdf        # Join PDFs together
pdftk A=in.pdf cat A5 output out.pdf  # Extract page from PDF

      You can also manipulate the content with cpdf:

      cpdf -draft in.pdf -o out.pdf      # Remove images
cpdf -blacktext in.pdf -o out.pdf  # Convert all text to black color
      1. Monitor the progress in terms of generated output

      # Write random data, encode it in base64 and monitor how fast it is being sent to /dev/null

      cat /dev/urandom | base64 | pv -lbri2 > /dev/null

# pv options:
#   -l,  lines
#   -b,  total counter
#   -r,  show rate
#   -i2, refresh every 2 seconds
      1. Find packages that have a given file in Ubuntu
      apt-file update
apt-file search dir/file.h
  • thingsiplay@beehaw.org
    4·
    3 days ago

    Fantastic list. I just want add one to this sublist. I use these often:

    1. Find files tips
    find . -maxdepth 1 -type f -printf '%f\n'

    -printf '%f\n': This is a function to print in a formatted manner, typically used in C or other languages. %f means here print the filename only, without directory or slashes. And add a newline off course, but you could also print it by space enclosed between quotes: "%f" I prefer this over executing separate echo process.

    -type f: This will limit the output depending on the filetype you define. Here f means files only. This can have multiple types too, in example directories or executables.

    -maxdepth 1: Do not search subdirectories, only look in current directory like ls does. You could specify more depth too. And there is even -mindepth 2 in example, if you want to skip some top level directories and only search somewhere deep. This makes sense if you have organized structure of directories in example.