Commands by sil (8)

  • There's been a few times I've needed to create random numbers. Although I've done so in PERL, I've found Ruby is actually faster. This script generates 20 random "10" digit number NOT A RANDOM NUMBER. Replace 20 (1..20) with the amount of random numbers you need generated Show Sample Output

    ruby -e "puts (1..20).map {rand(10 ** 10).to_s.rjust(10,'0')}"
    sil · 2009-05-27 19:52:53 3
  • self explanatory see sample output Show Sample Output

    perl -lpe'1 while s/^([-+]?\d+)(\d{3})/$1.$2/'
    sil · 2009-02-18 21:54:22 1
  • Alrighty, so I was really bored ;) Show Sample Output

    sil · 2009-02-18 17:22:26 1
  • Insert a comma where necessary when counting large numbers. I needed to separate huge amounts of packets and after 12+ hours of looking in a terminal, I wanted it in readable form. Show Sample Output

    perl -pe '$_=reverse;s/\d{3}(?=\d)(?!.*?\.)/$&,/g;$_=reverse'
    sil · 2009-02-18 16:34:18 0
  • Blacklisted is a compiled list of all known dirty hosts (botnets, spammers, bruteforcers, etc.) which is updated on an hourly basis. This command will get the list and create the rules for you, if you want them automatically blocked, append |sh to the end of the command line. It's a more practical solution to block all and allow in specifics however, there are many who don't or can't do this which is where this script will come in handy. For those using ipfw, a quick fix would be {print "add deny ip from "$1" to any}. Posted in the sample output are the top two entries. Be advised the blacklisted file itself filters out RFC1918 addresses (10.x.x.x, 172.16-31.x.x, 192.168.x.x) however, it is advisable you check/parse the list before you implement the rules Show Sample Output

    wget -qO -|awk '!/#|[a-z]/&&/./{print "iptables -A INPUT -s "$1" -j DROP"}'
    sil · 2009-02-18 16:08:23 7
  • I've got this posted in one of my .bash_profiles for humor whenever I log in. Show Sample Output

    wget -qO -|sed -n '65p'|awk 'gsub(/<span><br>.*/,"")&&1'|perl -p -e 's:myScroller1.addItem\("<span class=atHeaderOrange>::g;s:</span> <span class=snubFontSmall>::g;s:&quot;:":g;s:^:\n:g;s:$:\n:'
    sil · 2009-02-18 15:05:13 1
  • I sometimes have large files of MAC addresses stored in a file, some databases need the information stored with the semicolon (makes for easier programming a device) others don't. I have a barcode to text file scanner which usually butchers MAC addresses so this was the fix> I initially did this in awk ;) awk '{for(i=10;i>=2;i-=2)$0=substr($0,1,i)":"substr($0,i+1);print}' mac_address_list Show Sample Output

    sed 's/\(..\)/\1:/g;s/:$//' mac_address_list
    sil · 2009-02-18 14:38:37 0
  • This comes in handy if you have daemons/programs that have potential issues and stop/disappear, etc., can be run in cron to ensure that a program remains up no matter what. Be advised though, if a program did core out, you'd likely want to know why (gdb) so use with caution on production machines.

    ps -C thisdaemon || { thisdaemon & }
    sil · 2009-02-18 14:12:17 0

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Generic shell function for modifying files in-place
Some commands (such as sed and perl) have options to support in-place editing of files, but many commands do not. This shell function enables any command to change files in place. See the sample output for many examples. The function uses plain sh syntax and works with any POSIX shell or derivative, including zsh and bash.

Getting information about model no. of computer
This command gives a model information of a computer. Also useful in determining the host is a VM machine or actual physical machine.

Install pip with Proxy
Installs pip packages defining a proxy

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

du and sort to find the biggest directories in defined filesystem
This command give a human readable result without messing up the sorting.

Apply substitution only on the line following a marker
I've been auto-generating some complex GnuPlots; with multiplots the first plot of each group needs to be a 'plot' whereas the others need to be 'replots' to allow overplotting/autoscaling/etc to work properly. This is used to replace only the first instance of 'replot'.

download and unpack tarball without leaving it sitting on your hard drive

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

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

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