Commands tagged bash (821)

  • Thanks for the submit! My alternative produces summaries only for directories. The original post additionally lists all files in the current directory. Sometimes the files, they just clutter up the output. Once the big directory is located, *then* worry about which file(s) are consuming so much space.


    -1
    du -kd | egrep -v "/.*/" | sort -n
    rmbjr60 · 2010-03-30 15:40:35 3
  • The shell has perfectly adequate pattern matching for simple expressions. Show Sample Output


    -1
    function ends_in_y() { case $(date +%A) in *y ) true ;; * ) false ;; esac } ; ends_in_y && echo ok
    unixmonkey9199 · 2010-04-06 22:18:52 3
  • Essentially the same as funky's alias, but will not traverse filesystems and has nicer formatting. Show Sample Output


    -1
    alias dush="du -xsm * | sort -n | awk '{ printf(\"%4s MB ./\",\$1) ; for (i=1;i<=NF;i++) { if (i>1) printf(\"%s \",\$i) } ; printf(\"\n\") }' | tail"
    dopeman · 2010-07-15 10:38:27 4
  • forces user to rw, group to r, and other to no access. files will not be marked executable. directories will be executable for users and groups only. Show Sample Output


    -1
    chmod -R u=rw-x+X,g=r-x+X,o= .
    donnoman · 2010-07-16 18:42:00 5
  • Output the html from xkcd's index.html, filter out the html tags, and then view it in gwenview. Show Sample Output


    -1
    gwenview `wget -O - http://xkcd.com/ | grep 'png' | grep '<img src="http://imgs.xkcd.com/comics/' | sed s/title=\".*//g | sed 's/.png\"/.png/g' | sed 's/<img src=\"//g'`
    hunterm · 2010-08-24 22:21:51 4
  • Shorter version with curl and awk


    -1
    eog `curl 'http://xkcd.com/' | awk -F "ng): |</h" '/embedding/{print $2}'`
    dog · 2010-08-25 14:04:30 3
  • It works in every linux box Show Sample Output


    -1
    cat /proc/cpuinfo
    magicjohnson_ · 2010-09-24 09:27:58 3
  • The command was too long for the command box, so here it is: echo $(( `wget -qO - http://i18n.counter.li.org/ | grep 'users registered' | sed 's/.*\<font size=7\>//g' | tr '\>' ' ' | sed 's/<br.*//g' | tr ' ' '\0'` + `curl --silent http://www.dudalibre.com/gnulinuxcounter?lang=en | grep users | head -2 | tail -1 | sed 's/.*<strong>//g' | sed 's/<\/strong>.*//g'` )) This took me about an hour to do. It uses wget and curl because, dudalibre.com blocks wget, and wget worked nicely for me. Show Sample Output


    -1
    Check the Description below.
    hunterm · 2010-10-07 04:22:32 3
  • Often times you run a command in the terminal and you don't realize it's going to take forever. You can open a new terminal, but you lose the local history of the suspended one. You can stop the running command using , but that may produce undesirable side-effects. suspends the job, and (assuming you have no other jobs running in the background) %1 resumes it. Appending & tells it to run in the background. You now have a job running concurrently with your terminal. Note this will still print any output to the same terminal you're working on. Tested on zsh and bash. Show Sample Output


    -1
    <ctrl+z> %1 &
    joem86 · 2010-10-25 17:43:38 5
  • Just added view with the eog viewer.


    -1
    wget -O xkcd_$(date +%y-%m-%d).png `lynx --dump http://xkcd.com/|grep png`; eog xkcd_$(date +%y-%m-%d).png
    theanalyst · 2010-10-27 13:42:55 3
  • Uses xargs to call the second grep with the first grep's results as arguments


    -1
    grep -l bar *.log | xargs grep -l foo
    dlebauer · 2011-01-10 19:54:46 3
  • This will tighten up security for your box. The default value for PermitRootLogin sadly is 'yes'.


    -1
    s=/etc/ssh/sshd_config;r=PermitRootLogin;cp $s{,.old}&& if grep $r $s;then sed "s/$r yes/$r no/" $s.old > $s; else echo $r no >> $s;fi
    kzh · 2011-01-30 23:41:59 11
  • Here's a bash version using an array.


    -1
    a=(*); echo ${a[$((RANDOM % ${#a[@]}))]}
    putnamhill · 2011-03-18 13:24:52 3
  • Sometimes you might need to have two copies of data that is in tar. You might unpack, and then copy, but if IO is slow, you might lower it by automatically writing it twice (or more times)


    -1
    mkdir copy{1,2}; gzip -dc file.tar.gz | tee >( tar x -C copy1/ ) | tar x -C copy2/
    depesz · 2011-04-14 17:02:05 5

  • -1
    echo $(( $( date +%s ) - $( stat -c %Y * | sort -nr | head -n 1 ) ))
    depesz · 2011-05-12 14:29:45 3
  • urldecode files in current directrory


    -1
    ls * | while read fin;do fout=$(echo -n $fin | sed -e's/%\([0-9A-F][0-9A-F]\)/\\\\\x\1/g' | xargs echo -e);if [ "$fout" != "$fin" ];then echo "mv '$fin' '$fout'";fi;done | bash -x
    pawelb1973 · 2011-05-18 07:24:54 81
  • Newer versions of Dropbox let you choose the location for your Dropbox folder. If you use script to put things into your Dropbox folder (todo list, screenshots, torrents etc.) but have the Dropbox folder in different locations on your other computers this lets you use the same script on all systems without having to tell it where the Dropbox folder is. Show Sample Output


    -1
    sqlite3 $HOME/.dropbox/config.db "select value from config where key like '%dropbox_path%'"
    mobilediesel · 2011-06-05 08:26:02 13
  • Outputs the real time it takes a Redis ping to run in thousands of a second without any proceeding 0's. Useful for logging or scripted action.


    -1
    TIME=$( { time redis-cli PING; } 2>&1 ) ; echo $TIME | awk '{print $3}' | sed 's/0m//; s/\.//; s/s//; s/^0.[^[1-9]*//g;'
    allrightname · 2011-08-11 19:09:49 4

  • -1
    RANGE=`wc -l /usr/share/dict/words | sed 's/^\([0-9]*\) .*$/\1/'`; for i in {1..4}; do let "N = $RANDOM % $RANGE"; sed -n -e "${N}p" /usr/share/dict/words | tr -d '\n'; done; RANGE=100; let "N = $RANDOM % $RANGE"; echo $N
    unixmonkey24597 · 2011-08-16 07:04:57 3
  • uses fifo and sets to a specific port. In this case 4201.


    -1
    mkfifo ._b; nc -lk 4201 0<._b | /bin/bash &>._b;
    gt · 2011-08-21 05:22:41 3
  • This is an "argument calculator" funktion. The precision is set to 4 and you can use dot (.) or comma (,) as decimal mark (which is great for german users with a comma on the numpad).


    -1
    calc() { echo "scale=4; ${*//,/.}" | bc -l; }
    fpunktk · 2011-10-24 19:58:20 4
  • Schematics: command [options] [paste your variable here] parameter command [options] [paste entire column of variables here] parameter ... (hard-code command "c" and parameter "e" according to your wishes: in example shown command = "cp -a" and parameter = "~") Features: - Quick exchange only variable part of a long command line - Make variable part to be an entire column of data (i.e. file list) - Full control while processing every single item Hints: Paste column of data from anywhere. I.e. utilize the Block Select Mode to drag, select and copy columns (In KDE Konsole with Ctrl+Alt pressed, or only Ctrl pressed in GNOME Terminal respectively). Disadvantages: You can paste only one single variable in a row. If there are more space separated variables in a row only first one will be processed, but you can arrange your variables in a column instead. To transpose rows to columns or vice versa look at Linux manual pages for 'cut' and 'paste'. TODO: - add edit mode to vary command "c" and parameter "e" on the fly - add one edit mode more to handle every list item different - add y/n/a (=All) instead of only y(=default)/n to allowed answers Disclaimer: The code is not optimized, only the basic idea is presented here. It's up to you to shorten code or extend the functionality. Show Sample Output


    -1
    c="cp -a";e="~";echo -e "\npaste\n";i=0;k="1"; while [[ "$k" != "" ]]; do read -a k;r[i]=$k;((i++));done;i=0;while :;do t=${r[i]};[ "$t" == "" ] && break; g=$(echo $c ${r[i]} $e);echo -e $g "\ny/n?";read y;[ "$y" != "n" ] && eval $g;((i++));done
    knoppix5 · 2011-12-04 12:45:44 4
  • Mac install ssh-copy-id From there on out, you would upload keys to a server like this: (make sure to double quote the full path to your key) ssh-copy-id -i "/PATH/TO/YOUR/PRIVATE/KEY" username@server or, if your SSH server uses a different port (often, they will require that the port be '2222' or some other nonsense: (note the double quotes on *both* the "/path/to/key" and "user@server -pXXXX"): ssh-copy-id -i "/PATH/TO/YOUR/PRIVATE/KEY" "username@server -pXXXX" ...where XXXX is the ssh port on that server


    -1
    sudo curl "http://hg.mindrot.org/openssh/raw-file/c746d1a70cfa/contrib/ssh-copy-id" -o /usr/bin/ssh-copy-id && sudo chmod 755 /usr/bin/ssh-copy-id
    misterich · 2012-02-09 20:29:24 5
  • You need to have mtr installed on your host.


    -1
    mtr google.com
    d_voge · 2012-02-19 22:27:48 3
  • tail() { thbin="/usr/bin/tail"; if [ "${1:0:1}" != "-" ]; then fc=$(($#==0?1:$#)); lpf="$((($LINES - 3 - 2 * $fc) / $fc))"; lpf="$(($lpf<1?2:$lpf))"; [ $fc -eq 1 ] && $thbin -n $lpf "$@" | /usr/bin/fold -w $COLUMNS | $thbin -n $lpf || $thbin -n $lpf "$@"; else $thbin "$@"; fi; unset lpf fc thbin; } This is a function that implements an improved version of tail. It tries to limit the number of lines so that the screen is filled completely. It works with pipes, single and multiple files. If you add different options to tail, they will overwrite the settings from the function. It doesn't work very well when too many files (with wrapped lines) are specified. Its optimised for my three-line prompt. It also works for head. Just s/tail/head/g Don't set 'thbin="tail"', this might lead to a forkbomb.


    -1
    tail() { thbin="/usr/bin/tail"; if [ "${1:0:1}" != "-" ]; then fc=$(($#==0?1:$#)); lpf="$((($LINES - 3 - 2 * $fc) / $fc))"; lpf="$(($lpf<1?2:$lpf))"; [ $fc -eq 1 ] && $thbin -n $lpf "$@" | /usr/bin/fold -w $COLUMNS | $thbin -n $lpf || $thbin -n $lpf...
    fpunktk · 2012-03-23 19:00:30 3
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Redirect incoming traffic to SSH, from a port of your choosing
Stuck behind a restrictive firewall at work, but really jonesing to putty home to your linux box for some colossal cave? Goodness knows I was...but the firewall at work blocked all outbound connections except for ports 80 and 443. (Those were wide open for outbound connections.) So now I putty over port 443 and have my linux box redirect it to port 22 (the SSH port) before it routes it internally. So, my specific command would be: $iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-ports 22 Note that I use -A to append this command to the end of the chain. You could replace that with -I to insert it at the beginning (or at a specific rulenum). My linux box is running slackware, with a kernel from circa 2001. Hopefully the mechanics of iptables haven't changed since then. The command is untested under any other distros or less outdated kernels. Of course, the command should be easy enough to adapt to whatever service on your linux box you're trying to reach by changing the numbers (and possibly changing tcp to udp, or whatever). Between putty and psftp, however, I'm good to go for hours of time-killing.

Simple colourized JSON formatting for BASH
Leave out pygmentize or `pip install pygments` first.

Protect your eye
Redshift will adjust the color temperature and protects eye at night -b : will adjust the brightness

Find 10 largest files in git history

Interactively build regular expressions
txt2regex can be interactive or noninteractive and generates regular expressions for a variety of dialects based on user input. In interactive mode, the regex string builds as you select menu options. The sample output here is from noninteractive mode, try running it standalone and see for yourself. It's written in bash and is available as the 'txt2regex' package at least under debian/ubuntu.

check open ports
Tested in Linux and OSX

Block an IP address from connecting to a server
This appends (-A) a new rule to the INPUT chain, which specifies to drop all packets from a source (-s) IP address.

adjust laptop display hardware brightness [non root]

use jq to validate and pretty-print json output
the `jq` tool can also be used do validate json files and pretty print output `cat file.json | jq` 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/

Filter the output of a file continously using tail and grep
The OPs solution will work, however on some systems (bsd), grep will not filter the data, unless the --line-buffered option is enabled.


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