Commands by leprasmurf (5)

  • Copy a file over SSH without SCP

    I have come across multiple situations where I could only get to a server from a very restrictive bounce point which would not allow file transfers. I was able to uuencode a file, copy the output to a text file over putty, and then uudecode the file to transfer it. This works with any kind of file. Show Sample Output


    -4
    uuencode -m <filename> <filename>
    leprasmurf · 2009-12-22 15:28:59 4
  • NICs, IPs, and Mac

    Needed to get the Mac of various devices on a solaris box, but didn't have root. This command used awk to display the Network device, the IP, and the MAC a line at a time.


    1
    ifconfig -a | nawk 'BEGIN {FS=" "}{RS="\n"}{ if($1~ /:/) {printf "%s ", $1}}{ if($1=="inet") {print " -- ",system("arp "$2)}}'|egrep -v "^[0-9]$"
    leprasmurf · 2009-03-02 23:15:13 9
  • test connection if ICMP is disabled

    Telnet will make a tcp connection to a remote ip/port to test connectivity. If it times out, it's not reaching the host (maybe the firewall is blocking it). If connection is refused, it's reaching the host, but either the service is not listening on that port, or it's locked. Show Sample Output


    -2
    telnet <ip> <port>
    leprasmurf · 2009-02-12 19:11:03 13
  • Use last argument of last command

    Bash shortcut to work with the last argument of your last command Show Sample Output


    15
    file !$
    leprasmurf · 2009-02-06 15:41:08 25
  • Perl check if library is installed

    Quick command to check if Perl library is installed on your server. Show Sample Output


    0
    perl -e "use SOAP::Lite"
    leprasmurf · 2009-02-06 15:26:37 17

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Get memory total from /proc/meminfo in Gigs

Display Spinner while waiting for some process to finish
alternatively, run the spinner for 5 seconds: timeout 5 bash -c 'spinner=( Ooooo oOooo ooOoo oooOo ooooO oooOo ooOoo oOooo); while true; do for i in ${spinner[@]}; do for j in seq 0 ${#i}; do echo -en "\b\b"; done; echo -ne "${i}"; sleep 0.2; done; done'

Get all IPs via ifconfig
works on Linux and Solaris. I think it will work on nearly all *nix-es

Produce a pseudo random password with given length in base 64
Of course you will have to install Digest::SHA and perl before this will work :) Maximum length is 43 for SHA256. If you need more, use SHA512 or the hexadecimal form: sha256_hex()

Delete all but the latest 5 files
yes 6 (tail from 6th line)

Play awesome rythmic noise using aplay
Try modifying the numbers in the "(i*(i>>8|i>>9)&46&i>>8))^(i&i>>13|i>>6)" part. Crudely stolen from http://www.xkcdb.com/9067

Use tee to process a pipe with two or more processes
Tee can be used to split a pipe into multiple streams for one or more process to work it. You can add more " >()" for even more fun.

Automatically find and re-attach to a detached screen session
man screen: "-D -R Attach here and now. In detail this means: If a session is running, then reattach. If necessary detach and logout remotely first. If it was not running create it and notify the user. This is the author?s favorite."

Show this month's calendar, with today's date highlighted
Explanation: * The date command evaluated to today's date with blank padded on the left if single digit * The grep command search and highlight today's date * The --before-context and --after-context flags displays up to 6 lines before and after the line containing today's date; thus completes the calendar. I have tested this command on Mac OS X Leopard and Xubuntu 8.10

FizzBuzz in one line of Bash
The (in)famous "FizzBuzz" programming challenge, answered in a single line of Bash code. The "|column" part at the end merely formats the output a bit, so if "column" is not installed on your machine you can simply omit that part. Without "|column", the solution only uses 75 characters. The version below is expanded to multiple lines, with comments added. for i in {1..100} # Use i to loop from "1" to "100", inclusive. do ((i % 3)) && # If i is not divisible by 3... x= || # ...blank out x (yes, "x= " does that). Otherwise,... x=Fizz # ...set x to the string "Fizz". ((i % 5)) || # If i is not divisible by 5, skip (there's no "&&")... x+=Buzz # ...Otherwise, append (not set) the string "Buzz" to x. echo ${x:-$i} # Print x unless it is blanked out. Otherwise, print i. done | column # Wrap output into columns (not part of the test).

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