How to convert SSH keypairs generated using PuttyGen(Windows) into key-pairs used by ssh-agent and KeyChain(Linux)

(Via http://stackoverflow.com/questions/2224066/how-to-convert-ssh-keypairs-generated-using-puttygenwindows-into-key-pairs-used)

puttygen supports exporting to an OpenSSH compatible format.

1. Open PuttyGen
2. Click Load
3. Load your private key
4. Go to Conversions->Export OpenSSH and export your private key
5. Copy your private key to ~/.ssh/id_dsa (or id_rsa).
6. Create the RFC 4716 version of the public key using ssh-keygen

ssh-keygen -e -f ~/.ssh/id_dsa > ~/.ssh/id_dsa_com.pub

7. Convert the RFC 4716 version of the public key to the OpenSSH format:

ssh-keygen -i -f ~/.ssh/id_dsa_com.pub > ~/.ssh/id_dsa.pub

One line webserver

$ python -m SimpleHTTPServer

Muito útil para testes ou compartilhamento rápido de arquivos.

CPU utilization of multi process program

(Via Emerson Gomes at Gemalto)

for a in FRWK RCA SAS GCCM GCDM GCDT;
do 
total=0; echo -ne `/usr/ucb/ps auxww | egrep \($a\) | awk '{print $3}' | while read i; do total=$(echo "$total + $i" | bc); echo $total; done | tail -1` \ ;
done

sed emulating Unix commands

(Via http://sed.sourceforge.net/local/docs/emulating_unix.txt)

SED emulating UNIX commands      by Aurelio Jargas
---------------------------         www.aurelio.net/en
                                    verde at aurelio.net


Here's the list of some UNIX commands that can be emulated
using SED. Please, if know about others, contribute!


 UNIX         |  SED
 -------------+----------------------------------------------------------------
 cat          |  sed ':'
 cat -s       |  sed '1s/^$//p;/./,/^$/!d'
 tac          |  sed '1!G;h;$!d'
 grep         |  sed '/patt/!d'
 grep -v      |  sed '/patt/d'
 head         |  sed '10q'
 head -1      |  sed 'q'
 tail         |  sed -e ':a' -e '$q;N;11,$D;ba'
 tail -1      |  sed '$!d'
 tail -f      |  sed -u '/./!d'
 cut -c 10    |  sed 's/\(.\)\{10\}.*/\1/'
 cut -d: -f4  |  sed 's/\(\([^:]*\):\)\{4\}.*/\2/'
 tr A-Z a-z   |  sed 'y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/'
 tr a-z A-Z   |  sed 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/'
 tr -s ' '    |  sed 's/ \+/ /g'
 tr -d '\012' |  sed 'H;$!d;g;s/\n//g'
 wc -l        |  sed -n '$='
 uniq         |  sed 'N;/^\(.*\)\n\1$/!P;D'
 rev          |  sed '/\n/!G;s/\(.\)\(.*\n\)/&\2\1/;//D;s/.//'
 basename     |  sed 's,.*/,,'
 dirname      |  sed 's,[^/]*$,,'
 xargs        |  sed -e ':a' -e '$!N;s/\n/ /;ta'
 paste -sd:   |  sed -e ':a' -e '$!N;s/\n/:/;ta'
 cat -n       |  sed '=' | sed '$!N;s/\n/ /'
 grep -n      |  sed -n '/patt/{=;p;}' | sed '$!N;s/\n/:/'
 cp orig new  |  sed 'w new' orig
 hostname -s  |  hostname | sed 's/\..*//'


To be reworked:

 echo 'Hi!'   |  sed 's/.*/Hi!/;q' <(yes)


NOTE: On MSDOS, use " instead '


-------------------------------------------------------------------------------

THANK YOU to:
  - Adam Peresztegi (Hungary)
  - Eric De Mund (USA)
  - Eric Pement and his "Sed 1liners" document
  - Don (Australia)
  - Thobias Salazar Trevisan (Brazil)
  - The sed-users@yahoogroups.com mailing list

grep -A for Solaris

(Via Edson Oliveira at Gemalto)

# nawk '/root/{c=7}c&&c--' /etc/passwd

Where c=7 is the number of lines you want to grep after.

df format problems

Sometimes when you get a df from Linux or Solaris, the device appears in on line, and the rest of the information on other line. Here’s a tip to avoid this:

Solaris:

1 – (http://unixsadm.blogspot.com/2008/05/custom-df-diskfree-column-output-in.html):

# df -g | nawk '{if (NR % 5 == 1) printf "%-22s", $1 ; if (NR % 5 == 4) printf "%-10s", "fstype " $1 "\n"; if (NR % 5 == 2) printf "%-30s",$1/2/1024/1024 " GB"; if (NR % 5 == 2) printf "%-30s", $4/2/1024/1024 " GB free "}'

2 –

# printf "%s\n" "$(df -k)"

3 –

# ${__?"$(df -k)"}

Linux (by Gux):

# df -P | column -t

Get pid from a specific port in solaris

(Via Gonzalo Barrio at Gemalto) Hi all, I used to do a netstat -lntp in Linux to get the process id binded to some port and this doesn't work on Solaris. So I googled and found the following script:

#!/bin/ksh

line='---------------------------------------------'
pids=$(/usr/bin/ps -ef | sed 1d | awk '{print $2}')

if [ $# -eq 0 ]; then
   read ans?"Enter port you would like to know pid for: "
else
   ans=$1
fi

for f in $pids
do
   /usr/proc/bin/pfiles $f 2>/dev/null | /usr/xpg4/bin/grep -q "port: $ans"
   if [ $? -eq 0 ]; then
      echo $line
      echo "Port: $ans is being used by PID:\c"
      /usr/bin/ps -ef -o pid -o args | egrep -v "grep|pfiles" | grep $f
   fi
done
exit 0

Simple and working, maybe it is useful for you all.

.bash_profile and .bashrc differences

In this article the author explains the differences between login shells, interactive shells and non-interactive shells:

http://hacktux.com/bash/bashrc/bash_profile

Inserting characters in the middle of a string

Recently I had a problem to solve that involved inserting a byte in the middle of a line, and it was 522K lines :(.

Sometime ago I saw a video from Aurélio that teaches how to accomplish that: http://vimeo.com/11744241

But you don't have to watch the video (its in portuguese). The simple way is using sed:

We will seach for anything ('s), change this anything to itself plus a new byte ('s/./&39) and say on which position ('s/./&39 /3):

$ echo "#####"  |sed 's/./&39 /3'
###39 ##

With almost the same code, we could change the 3rd character to something else:

$ echo "#####"  |sed 's/./3/3'
##3##

Remove distinct line with sed

sed '4d;7d' file.txt

This will remove lines 4 and 7 from file.txt

sed '4,7d' file.txt

But this is a range, so will remove lines from 4 to 7 from file.txt