search for a port number

2017-09-11 1 min read Bash Linux

I find myself doing google everytime I want to search for port number mapping. So, here is a short script to do just that 🙂

#!/bin/bash -
#===============================================================================
#
# FILE: portfind.sh
#
# USAGE: ./portfind.sh
#
# DESCRIPTION:
#
# OPTIONS: ---
# REQUIREMENTS: ---
# BUGS: ---
# NOTES: ---
# AUTHOR: Amit Agarwal (aka),
# ORGANIZATION:
# CREATED: 08/29/2017 19:00
# Last modified: Tue Aug 29, 2017 07:00PM
# REVISION: ---
#===============================================================================
set -o nounset # Treat unset variables as an error
#This is the directory where you have mappings file downloaded
ODIR=/root
ofile=$ODIR/service-names-port-numbers.xml

if [[ ! -f "$ofile" ]]
then
wget http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml -O "$ofile"
fi
which xmlstarlet >/dev/null 2>&1
if [[ $? == 0 ]]
then
echo "xmlstarlet is installed"
else
apt-get install xmlstarlet
fi

#### xmlstarlet el -u service-names-port-numbers.xml
## registry/record - protocol and number
proto=${2:-tcp}
port=${1:-21}
(echo '';sed '1,4d' $ofile) |xmlstarlet sel -t -m "//record[protocol='$proto'][number=$port]" -o "Number(Protocol): " -v number -o '(' -v protocol -o ')' -n -o "Description :" -v description -n

Check all vim colorschemes for minor issues

2013-10-10 2 min read Bash Vim Tips

Here is script that checks all the colorschemes in the current directory and corrects them if possible (Processing of the file is done with simple commands like sed, grep)

Checks that the color_name is same as Filename

Here is the script:

#!/bin/bash -
#===============================================================================
#
#          FILE: check_colors.sh
#
#         USAGE: ./check_colors.sh
#
#   DESCRIPTION:
#
#       OPTIONS: ---
#  REQUIREMENTS: ---
#          BUGS: ---
#         NOTES: ---
#        AUTHOR: Amit Agarwal (aka), 
#      REVISION:  ---
#===============================================================================
cd ~/.vim/colors
for i in *vim
do
    #echo "Processing $i"
    if [[ $(grep -c g:colors_name $i ) -eq 0 ]]; then
        if [[ $(grep -c colors_name $i ) -eq 0 ]]; then
            echo "File $i does not have colorname";
            missing=$missing" $i"
        else
            sed -i.bak '/colors_name/ s/.*/let g:colors_name="'${i//.vim}'"/g' $i
        fi
    else
        if [[ $(grep -c colors_name $i|grep let ) -gt 1 ]]; then
            echo "WARN ----->> File $i has more than one colorsname"
        fi
        colorname=$(grep g:colors_name $i|grep let| sed -e 's/"//g' -e 's/.*=//' |tr -d ' ')
        if [[ ${colorname}.vim != $i ]]; then
            echo "Filename $i does not match colorname $colorname .. correcting "
            sed -i.bak '/colors_name/ s/.*/let g:colors_name="'${i//.vim}'"/g' $i
            #sed -i.bak 's/(.*g:colors_name.*=)/1'${i//.vim}'/g' $i
        fi
    fi
done

if [[ x$missing != x ]] ; then
    echo "Missing colornames in $missing"
fi

Home grown mail scheduler with bash script and cron

2013-10-04 2 min read Bash Linux

If you are using Linux (Fedora/Ubuntu or anything else) then you do get a lot of tools and one of them is cron. Very very useful. Just write some script that can do the task for you, put it in cron and forget it. So, here is a home grown way to schedule mails.

First, copy this script below:

#!/bin/bash -
#===============================================================================
#
#          FILE: sched_mail.sh
#
#         USAGE: ./sched_mail.sh
#
#   DESCRIPTION:
#
#       OPTIONS: ---
#  REQUIREMENTS: ---
#          BUGS: ---
#         NOTES: ---
#        AUTHOR: Amit Agarwal (aka), 
#      REVISION:  ---
#===============================================================================

mailfile="~/mail"
if [[ $(wc -l $mailfile|awk '{print $1}' ) -ge 5 ]]
then
    to=$(grep ^To: $mailfile|sed 's/To: //')
    echo "Good to send mail... to = $to"
    sendmail -t <$mailfile
    echo "once mail is send, delete the contents of file"
    echo "sed -i '4,$ d' $mailfile"
fi

Now, create a file called mail in your home directory, with the following contents:

Delete all but some directories

2013-08-16 1 min read Bash Fedora Linux

I think, like me, you would have faced a lot of situations, where you wanted to delete all the files or directories in a location, leaving only the required files/directories. So, I have a directory containing lots of files/directories and I want to delete most of them except some 5/10 of them, how to I do it.

I finally wrote a small script to do that. First save list of files that you do not want to delete in file called “listnames” and then execute the below script. This will give you the rm commands that you need to execute. If you want you can execute the rm command from the script, but to be able to review, I just have the commands echoed.

Manage your servers the easy way with perl script over ssh with no remote client.

2013-05-06 8 min read Linux Perl

For a long time I have not posted any script. So, its not that I have not written anything new, but just that did not put them here in lack of time. So, here is one interesting one. The original idea came from one posted in one of the interesting blog here. But the problem with this one was that for every time, it ran in the cron, it would make multiple entries in the “last” output (about 10 or more with my modifications for differentiating between solaris and Linux). This is something which is not quite desirable. Hence I came up with this script which is based on html template and hence the output is also easier to manipulate. BTW, just the below script will not help, you would need to download the template files as well. In the list.txt file, you will have to put the usename, password and the server IP to monitor. The server could be any Linux or Solaris host.

Disable a few cores when you want to save power.

2012-12-28 2 min read Bash Fedora Linux

If you have a lot of CPU power and working on battery. If you do not need that much of power and would like to rather save some battery power by disabling some cpus then you can use the below script. This script disables cpus from 4 to 7. You can change the number in the for loop. You would need the sudo to be setup or remove sudo and run the script as root. The script will show you the currently active cpu’s before and after disabling the CPU’s.

quick bash script for datewise backup of directory

2012-12-12 1 min read Bash Linux

I was working on something and the data was very critical and needed backup. I wrote a bash script to back up the data every 5 hours with cron and bash script. Thought I will share that with you. Here is the script.

#!/bin/bash - 
#===============================================================================
#
#          FILE:  backup.sh
# 
#         USAGE:  ./backup.sh 
# 
#   DESCRIPTION:  Backup all the current files.
# 
#       OPTIONS:  ---
#  REQUIREMENTS:  ---
#          BUGS:  ---
#         NOTES:  ---
#        AUTHOR: Amit Agarwal (aka), amit.agarwal@roamware.com
#       COMPANY: Roamware India Pvt Ltd
#       CREATED: 08/19/2011 02:43:32 PM IST
#      REVISION:  ---
#===============================================================================
backupf=( a b c d) #Here you need to specify the directory you need to backup.
bkupdir="/tmp/backup/$(date +%Y)/$(date +%m)/$(date +%d)" #Here you can change the basedir for the backups
mkdir  -p $bkupdir
sudo tar cvfz $bkupdir/bkup_$(date "+%Y%m%d_%H%M").tgz $backupf[*] #Remove sudo if you do not need it.
echo "Backup created in dir $dir"

And then just add it to cron as “00 */5 * * * /home//bin/backup.sh”. Change the path if it does not match what is given here.

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