The document discusses Unix programming basics, focusing on home directories and path variables. It explains how to display and modify the path variable, which lists directories searched for commands. It also distinguishes between absolute and relative pathnames using examples.

1. UNIX PROGRAMMING
HOME, PATH, Pathnames

2. Home Directory
$ echo $HOME
/home/kumar

3. The PATH variable
List of directories searched by shell to locate the command.
$ echo $PATH
/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/home/kumar/.local/bin:/home/
kumar/bin
• add /opt/bin to PATH
$ PATH=$PATH:/opt/bin
$ echo $PATH
/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/home/kumar/.local/bin:/home/
kumar/bin:/opt/bin

4. Absolute and Relative pathname
Absolute pathname:
$ cat /home/kumar/login.sql
Relative pathname
$ cat /kumar/login.sql