Tag Archives: unix

How to Intrepret Shadow Passwords in UNIX

In modern UNIX and Linux systems, user passwords are encrypted and stored in the /etc/shadow file. On BSD systems, the passwords are kept in the /etc/master.passwd file. The encrypted password field in the file contains more than just the encrypted password, it contains additional information.

Shell Script: Calculate Yesterday’s Date on UNIX

shell script

There are times when you will need to calculate yesterday’s date in a UNIX shell script to run some date sensitive cron jobs. There are currently no standard command line tools in UNIX to perform such date arithmetic.

Recursive FTP from the Command Line

The default command line ftp client in most UNIX distributions do not support recursive downloads, even though recursive downloads is a basic feature in most GUI based ftp clients. But if you do not have access to the X-Windows or GUI, there are alternative ways to achieve the same result from the command line.

UNIX Terminal Session Management

Have you ever encountered the dreaded “Connection closed by foreign host” message when you were logged into a remote server via SSH and you were in the middle of some important task? You have most probably just lost your session and you will have to start your task all over again. Well, you can prevent this from happening by using the screen command available in most UNIX and Linux distributions.

Switch Between 32-bit and 64-bit Kernel in Solaris

Solaris, by default, loads a 64-bit kernel during boot up, if the hardware supports it.

If, for whatever reason, you need to load Solaris in 32-bit mode, the following commands can be used to switch between the 32-bit and 64-bit kernels.

Command Line Calendar

How often have you wanted to take a quick glance of the calendar in your desktop? You may need to click a couple of dozen of times on your desktop if the period your are interested in is more than a decade back.