If you have no other option but to use telnet with authentication to send mail 🙂
( echo "ehlo" sleep 1 auth login sleep 1 $(echo username |base64) sleep 1 $(echo password |base64) sleep 1 mail from: from-address sleep 1 rcpt to: recepient sleep 1 data sleep 1 subject: test test mail . exit ) |telnet server port
If you are doing some scripting and using ‘time’ command, then you know sometimes it becomes difficult to capture the output as the output would be something like this:
: amit ; time ls real 0m0.002s user 0m0.000s sys 0m0.001s
So, it is better to change that format. Here is simple example:
|
1
|
In bash you can use
!#
to refer to any parameter from the current command, example:
mv ak amit.!#:1.txt ls amit.ak.txt
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' $mailfile" fi
Now, create a file called mail in your home directory, with the following contents:
Continue readingI think, like me, you would have faced a lot of situations, where you wanted to delete all the files or directories in a location, leaving only the required files/directories. So, I have a directory containing lots of files/directories and I want to delete most of them except some 5/10 of them, how to I do it.
I finally wrote a small script to do that. First save list of files that you do not want to delete in file called “listnames” and then execute the below script. This will give you the rm commands that you need to execute. If you want you can execute the rm command from the script, but to be able to review, I just have the commands echoed.
Continue readingLots of times you want to convert tabs to spaces and sometimes from a shell script, if that is the case, then simple solution is “tidy“. First you need to install tidy as follows:
sudo yum install tidy
and then you can use the command tab2space.
tab2spcae
This will print the output to STDOUT by default which you can redirect if you want.
Continue readingI was working on something and the data was very critical and needed backup. I wrote a bash script to back up the data every 5 hours with cron and bash script. Thought I will share that with you. Here is the script.
#!/bin/bash - #=============================================================================== # # FILE: backup.sh # # USAGE: ./backup.sh # # DESCRIPTION: Backup all the current files. # # OPTIONS: --- # REQUIREMENTS: --- # BUGS: --- # NOTES: --- # AUTHOR: Amit Agarwal (aka), amit.agarwal@roamware.com # COMPANY: Roamware India Pvt Ltd # CREATED: 08/19/2011 02:43:32 PM IST # REVISION: --- #=============================================================================== backupf=( a b c d) #Here you need to specify the directory you need to backup. bkupdir="/tmp/backup/$(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.
Continue reading