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 2
  • Alrighty, so I was really bored ;) Show Sample Output

    sil · 2009-02-18 17:22:26 2
  • 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 1
  • 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 8
  • 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 1
  • 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 2

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Selecting a random file/folder of a folder
Also looks in subfolders

Kill all processes that don't belong to root/force logoff
explanation: grep -- displays process ids -v -- negates the matching, displays all but what is specified in the other options -u -- specifies the user to display, or in this case negate The process loops through all PIDs that are found by pgrep, then orders a forced kill to the processes in numerical order, effectively killing the parent processes first including the shells in use which will force the users to logout. Tested on Slackware Linux 12.2 and Slackware-current

Add fade in/out to first & last 25 frames of a video
Replace vid.mp4 with the path to your original video file, and out.mp4 to the path where you want to save the new file. To view the output first before saving, remove "-consumer avformat:out.mp4" from the end. Documentation for mlt framework and melt command can be found here:

Install pip with Proxy
Installs pip packages defining a proxy

Silently deletes lines containing a specific string in a bunch of files
This command will find all occurrences of one or more patterns in a collection of files and will delete every line matching the patterns in every file

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"

Numeric zero padding file rename
rename file name with fixed length nomeric format pattern

Inserts the results of an autocompletion in the command line
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)

Makes the permissions of file2 the same as file1
Also works with: $chgrp --reference file1 file2 $chown --reference file1 file2

make, or run a script, everytime a file in a directory is modified

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