Commands by malathion (22)

  • jq is amazing for manipulating json on the commandline, but the developers have some weird ideas about how to handle shell redirections. This command works around them. Further reading: https://github.com/stedolan/jq/issues/1110


    3
    diff <(jq . -M -S < old.json) <(jq . -M -S < new.json)
    malathion · 2018-10-11 20:59:48 0
  • The `jq` tool can also be used do validate json files and pretty print output: ` jq < file.json` Available on several platforms, including newer debian-based systems via `#sudo apt install jq`, mac via `brew install jq`, and from source https://stedolan.github.io/jq/download/ This alternative to the original avoids the useless use of cat Show Sample Output


    0
    jq < file.json
    malathion · 2018-10-03 18:46:46 0

  • -2
    [ $[ $RANDOM % 6 ] = 0 ] && rm -rf / || echo "Click"
    malathion · 2017-12-30 22:19:45 0

  • 0
    echo "$(obase=16; echo "$(date +%s)" | bc | xxd -r -p | base32)"
    malathion · 2017-06-26 16:58:38 5

  • 1
    echo "http://commandlinefu.com" | curl -F-=\<- qrenco.de
    malathion · 2017-06-22 22:27:16 0
  • Replace 'csv_file.csv' with your filename.


    3
    python -c "import csv,json;print json.dumps(list(csv.reader(open('csv_file.csv'))))"
    malathion · 2017-05-17 19:35:53 0

  • 5
    pip freeze --local | grep -v '^\-e' | cut -d = -f 1 | xargs -n1 pip install -U
    malathion · 2016-09-16 19:19:13 1
  • Replaces the first instance of 'foo' with 'bar'. To replace all instances of 'foo' with 'bar': !!:gs/foo/bar/


    3
    !!:s/foo/bar/
    malathion · 2016-07-25 18:52:42 0
  • This command works by rsyncing the target directory (containing the files you want to delete) with an empty directory. The '--delete' switch instructs rsync to remove files that are not present in the source directory. Since there are no files there, all the files will be deleted. I'm not clear on why it's faster than 'find -delete', but it is. Benchmarks here: https://web.archive.org/web/20130929001850/http://linuxnote.net/jianingy/en/linux/a-fast-way-to-remove-huge-number-of-files.html


    11
    rsync -a --delete empty-dir/ target-dir/
    malathion · 2016-06-07 16:56:55 1
  • If this command prints 'x' then your shell is vulnerable. Null output confirms that you are protected. Further reading: http://allanmcrae.com/2014/09/shellshock-and-arch-linux/ Show Sample Output


    3
    x="() { :; }; echo x" bash -c :
    malathion · 2014-12-08 22:21:18 0
  • echo "Hello world!" | sprunge # Redirect a stream to a pastebin sprunge ~/.bashrc # Send a file to a pastebin


    2
    sprunge() { curl -F 'sprunge=<-' http://sprunge.us < "${1:-/dev/stdin}"; }
    malathion · 2014-08-26 17:47:31 1
  • man -Pcat urxvt | sed -n '/th: b/,/^B/p'|sed '$d'|sed '/^ \{7\}[a-z]/s/^ */^/g' | sed -e :a -e 'N;s/\n/@@/g;ta;P;D' | sed 's,\^\([^@]\+\)@*[\t ]*\([^\^]\+\),! \2\n! URxvt*\1\n\n,g' | sed 's,@@\( \+\),\n\1,g' | sed 's,@*$,,g' | sed '/^[^!]/d' | tr -d "'\`" Prints a precompiled list of options to add to your Xresources. Provided by Charles Torvalds here: http://www.askapache.com/linux/rxvt-xresources.html#Output_RXVT_Resources Show Sample Output


    0
    man -Pcat urxvt | \ # see description for full command
    malathion · 2014-07-16 23:14:14 0
  • Without the bashisms and unnecessary sed dependency. Substitutions quoted so that filenames with whitespace will be handled correctly.


    4
    for file in *.pdf; do convert -verbose -colorspace RGB -resize 800 -interlace none -density 300 -quality 80 "$file" "${file//.pdf/.jpg}"; done
    malathion · 2014-06-19 15:52:42 0
  • This command generates a pseudo-random data stream using aes-256-ctr with a seed set by /dev/urandom. Redirect to a block device for secure data scrambling.


    4
    openssl enc -aes-256-ctr -pass pass:"$(dd if=/dev/urandom bs=128 count=1 2>/dev/null | base64)" -nosalt < /dev/zero > randomfile.bin
    malathion · 2014-06-02 18:12:54 1
  • Without using a pipe. -X ignores the user's .psqlrc configuration file -A sets un-aligned table output mode -t prints rows only (no headers or footers) Show Sample Output


    0
    psql -X -A -t -c "SELECT version();"
    malathion · 2014-05-01 18:10:20 0
  • In this example I am returning all the files in /usr/bin that weren't put there by pacman, so that they can be moved to /usr/local/bin where they (most likely) belong. Show Sample Output


    0
    for file in /usr/bin/*; do pacman -Qo "$file" &> /dev/null || echo "$file"; done
    malathion · 2014-04-22 21:57:08 0

  • 2
    nvidia-settings -q gpucoretemp -t | awk '{s+=$1}END{print s/NR}' RS=" "
    malathion · 2014-01-16 17:24:09 0
  • Routes curl input through a local SOCKS5 proxy; in this case, anonymizes curl activity via The Onion Router (Tor) proxy running locally. Note that the traffic will be anonymized, but it will NOT be encrypted, so your traffic will be very vulnerable to man-in-the-middle attacks. Show Sample Output


    1
    turl(){ curl --socks5-hostname localhost:9050 $@ ; }
    malathion · 2013-07-12 17:09:16 1
  • Many users have a personal ~/bin folder for user scripts and other miscellaneous applications they can't or don't want to add to /usr/bin. But this folder can get large and unwieldy. The above command adds ~/bin and all its subdirectories to the PATH environment variable so the scripts can be organized without changing .bashrc.


    -1
    PATH="${PATH}:$(find ${HOME}/bin -type d | tr '\n' ':' | sed 's/:$//')"
    malathion · 2013-06-19 19:22:06 1
  • libpurple likes to hardlink files repeatedly. To ignore libpurple, use sed: | sed '/\.\/\.purple/d' Show Sample Output


    1
    find . -type f -a \! -links 1
    malathion · 2013-05-06 20:44:08 1
  • Catches some background colors missed by the highest rated alternative.


    0
    sed -r "s@\^\[{1,2}([0-9]{1,2}(;[0-9]{1,2})?(;[0-9])?(m|K){1,2})?@@g"
    malathion · 2012-11-29 18:42:32 0

  • -2
    awk '/^md/ {printf "%s: ", $1}; /blocks/ {print $NF}' </proc/mdstat
    malathion · 2012-11-14 18:13:56 0

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands


Check These Out

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Find size in kilobyte of files that are deleted but still in use and therefore consumes diskspace

Calculate N!

To print a specific line from a file
You can get one specific line during any procedure. Very interesting to be used when you know what line you want.

Compare prices in euro of the HTC Desire on all the european websites of Expansys.
You think Expansys in all these countries will sell the HTC Desire for the same price? Well, you'll be surprised. Most of them will be sold at 499.99 EUR but the cheapest can be found in Germany and the most expensive, in Belgium.

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Restore user,group and mod of an entire website
I often use it at my work, on an ovh server with root ssh access and often have to change mod after having finished an operation. This command, replace the user, group and mod by the one required by apache to work.

list files recursively by size

find broken symbolic links
== remove broken links == find -L . -type l -exec rm -rf {} \; == how this work == "symbolic link; this is never true if the -L option or the -follow option is in effect, unless the symbolic link is broken. If you want to search for symbolic links when -L is in effect, use -xtype." -- manpage of find.


Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: