Thursday, September 25, 2008

Using find to do operations on multiple files

I learned this technique from my sifoo when he had to change a bunch of html files to unix using dos2unix command. I found that this is very useful and I would like to share it :)

To find files with the extension .html in the current folder and run command dos2unix to all of them:

  • $ find . -type f -name *html -exec dos2unix ’{}’ \;
To see more use of find, refer to find manpage:
  • $ man find

Thursday, September 11, 2008

Send email with attachment from terminal

To be able to do as the above mentioned, a tool named mutt is needed. Mutt is a mail user agent (MUA) and a very excellent one in my opinion. To install mutt:

  • # yum install mutt
To send email, you can use this commands (Choose whichever you like):
  • # echo "your messages" | mail -s "your subject" johndoe@yahoo.com
    • where -s is for subject and johndoe@yahoo.com is your recipient name
  • # echo "your messages" | mutt -s "your subject" johndoe@yahoo.com
    • where -s is for subject and johndoe@yahoo.com is your recipient name
To send email with attachment
  • # echo "your messages" | mutt -s "your subject" -a /path/to/attachment johndoe@yahoo.com
    • where -s is for subject, johndoe@yahoo.com is the recipient name and /path/to/atachment is the path to attachment file
Hope this will be helpful...:)

Tuesday, September 9, 2008

Ubuntu forgotten password

What to do when you forgot your password for your ubuntu machine?? Here are some simple steps on how to change the password using single user mode.

  1. Reboot the machine
  2. When grub is loading, press 'Esc'
  3. Choose 'Ubuntu kernel...........(recovery mode)'
    • Press 'e' to edit the kernel parameter
    • Append 'single init=/bin/bash' to the kernel parameter
  4. Press 'b' to boot from that particular kernel
  5. You will enter single user mode
  6. Your hard drive will be in read-only mode. Remount it in read-write mode
    • # mount -o remount,rw /dev/sda1
  7. Change your passwd
    • # passwd user
  8. Reboot your machine
  9. Access your machine using your new password
Congratulations, you just changed you user password using single user mode