30 interesting commands for the Linux shell
30 interesting commands for the Linux shell
thediligentdeveloper.com
30 interesting commands for the Linux shell – The Diligent Developer
11 comments
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Most people will run a post 2.6 kernel, so prlimit will be available as an interesting alternative to ulimit.
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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
fuseruntil I realized it's not a base install on many distros, so I switched tolsofwhich 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.
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Looks like the site is down or blocked in my country.
Could anyone please be so nice and copy paste those commands here?
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- Supervise command (run every 2s)
watch "ls -larth"- Kill program using one port
sudo fuser -k 8000/tcp- Limit memory usage for following commands
ulimit -Sv 1000 # 1000 KBs = 1 MB ulimit -Sv unlimited # Remove limit- Rename selected files using a regular expression
rename 's/\.bak$/.txt/' *.bak- Get full path of file
readlink -f file.txt- List contents of tar.gz and extract only one file
tar tf file.tgz tar xf file.tgz static- List files by size
ls -lS- Nice trace route
mtr google.com- 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- Print text ad infinitum
yes yes hello- Who is logged in?
w- Prepend line number
ls | nl- Grep with Perl like syntax (allows chars like \t)
grep -P "\t"- Cat backwards (starting from the end)
tac file- 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- Run command every time a file is modified
while inotifywait -e close_write document.tex do make done- Copy to clipboard
cat file.txt | xclip -selection clipboard- Spell and grammar check in Latex
detex file.tex | diction -bsYou may need to install the following: sudo apt-get install diction texlive-extra-utils.
- Check resources' usage of command
/usr/bin/time -v ls- Randomize lines in file
cat file.txt | sort -R cat file.txt | sort -R | head # Pick a random sambpleEven better (suggested by xearl in Hacker news):
shuf file.txt- 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 backgroundOf course, you can also use screen or tmux for this purpose.
- Run a command for a limited time
timeout 10s ./script.shRestart every 30 minutes
while true; do timeout 30m ./script.sh; done- Combine lines from two sorted files
comm file1 file2Prints 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.
- Split long file in files with same number of lines
split -l LINES -d file.txt output_prefix- 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- 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- Create empty file of given size
fallocate -l 1G test.img- 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 PDFYou 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- 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- Find packages that have a given file in Ubuntu
apt-file update apt-file search dir/file.h-
Thank you very much!
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You the best.
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Nice.
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...and renice.
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Fantastic list. I just want add one to this sublist. I use these often:
- 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.%fmeans 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 separateechoprocess.-type f: This will limit the output depending on the filetype you define. Herefmeans files only. This can have multiple types too, in example directories or executables.-maxdepth 1: Do not search subdirectories, only look in current directory likelsdoes. You could specify more depth too. And there is even-mindepth 2in 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. -
The most interesting command for the Linux shell is known as Barmin patch.
11 comments
Actually yeah, those are.