Commands by Josay (5)


  • 2
    echo "aBcDeFgH123" | tr a-z A-Z
    Josay · 2009-08-25 11:06:31 0
  • In Bash, when defining an alias, one usually loses the completion related to the function used in that alias (that completion is usually defined in /etc/bash_completion using the complete builtin). It's easy to reuse the work done for that completion in order to have smart completion for our alias. That's what is done by this command line (that's only an example but it may be very easy to reuse). Note 1 : You can use given command line in a loop "for old in apt-get apt-cache" if you want to define aliases like that for many commands. Note 2 : You can put the output of the command directly in your .bashrc file (after the ". /etc/bash_completion") to always have the alias and its completion Show Sample Output


    4
    old='apt-get'; new="su-${old}"; command="sudo ${old}"; alias "${new}=${command}"; $( complete | sed -n "s/${old}$/${new}/p" ); alias ${new}; complete -p ${new}
    Josay · 2009-08-10 00:15:05 0
  • A common mistake in Bash is to write command-line where there's command a reading a file and whose result is redirected to that file. It can be easily avoided because of : 1) warnings "-bash: file.txt: cannot overwrite existing file" 2) options (often "-i") that let the command directly modify the file but I like to have that small function that does the trick by waiting for the first command to end before trying to write into the file. Lots of things could probably done in a better way, if you know one... Show Sample Output


    2
    buffer () { tty -s && return; tmp=$(mktemp); cat > "${tmp}"; if [ -n "$1" ] && ( ( [ -f "$1" ] && [ -w "$1" ] ) || ( ! [ -a "$1" ] && [ -w "$(dirname "$1")" ] ) ); then mv -f "${tmp}" "$1"; else echo "Can't write in \"$1\""; rm -f "${tmp}"; fi }
    Josay · 2009-07-27 20:21:15 3
  • Pressing ESC then * will insert in the command line the results of the autocompletion. It's hard to explain but if you look the sample output or do echo ESC * you will understand quickly. By the way, few reminders about ESC : - Hold ESC does the same thing as tab tab - 'ESC .' inserts the last argument of last command (can be done many times in order to get the last argument of all previous commands) Show Sample Output


    65
    ESC *
    Josay · 2009-06-14 21:17:40 18
  • command | my_irc Pipe whatever you want to this function, it will, if everything goes well, be redirected to a channel or a user on an IRC server. Please note that : - I am not responsible of flood excesses you might provoke. - that function does not reply to PINGs from the server. That's the reason why I first write in a temporary file. Indeed, I don't want to wait for inputs while being connected to the server. However, according to the configuration of the server and the length of your file, you may timeout before finishing. - Concerning the server, the variable content must be on the form "irc.server.org 6667" (or any other port). If you want to make some tests, you can also create a fake IRC server on "localhost 55555" by using netcat -l -p 55555 - Concerning the target, you can choose a channel (beginning with a '#' like "#chan") or a user (like "user") - The other variables have obvious names. Show Sample Output


    1
    function my_irc { tmp=`mktemp`; cat > $tmp; { echo -e "USER $username x x :$ircname\nNICK $nick\nJOIN $target"; while read line; do echo -e "PRIVMSG $target :$line"; done < $tmp; } | nc $server > /dev/null ; rm $tmp; }
    Josay · 2009-06-11 22:14:48 0

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Find the package that installed a command

Quick HTML image gallery
My take on the original: even though I like the other's use of -exec echo, sed just feels more natural. This should also be slightly easier to improve. I expanded this into a script as an exercise, which took about 35 minutes (had to look up some docs): http://bitbucket.org/kniht/nonsense/src/7c1b46488dfc/commandlinefu/quick_image_gallery.py

What is my ip?

Get the current svn branch/tag (Good for PS1/PROMPT_COMMAND cases)
Get the svn info, grep for the "URL" of the repository, pull out the tag/branch/trunk, and then just show the helpful/meaningful bit.

deaggregate ip ranges
Taking file with ip ranges, each on it's own line like: $cat ipranges.txt 213.87.86.160-213.87.86.193 213.87.87.0-213.87.88.255 91.135.210.0-91.135.210.255 command returns deaggregated ip ranges using ipcalc deaggregate feature like that: 213.87.86.160/27 213.87.86.192/31 213.87.87.0/24 213.87.88.0/24 91.135.210.0/24 Useful for configuring nginx geo module

Get your outgoing IP address
should be very consistent cause it's google :-)

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

google chart api
http://chart.apis.google.com/chart?chs=450x200&cht=p3&chtt=Browser+Usage+on+Wikimedia&chl=IE%2834.2%%29|Firefox%2823.6%%29|Chrome%2820.6%%29|Safari%2811.2%%29|Opera%285.0%%29|Android%281.9%%29|Other%283.5%%29&chd=t:34.2,23.6,20.6,11.2,5.0,1.9,3.5

View ~/.ssh/known_hosts key information
Will return the SSH server key information for each host you have in your ~/.ssh/known_hosts file, including key size, key fingerprint, key IP address or domain name, and key type.

List all TCP opened ports on localhost in LISTEN mode
Alternative of OJM snippet : This one show the IP too, where ports bind. It's very important, because if there's only 127.0.0.1 instead of 0.0.0.0, connections from internet are rejected.


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