i am not clear at some places i saw that assigning a env var with colon ':' like
export PATH=/usr/bin:/usr/ucb:/etc:/usr/sbin:.:/usr/platform/sun4u/sbin
here you can find : and a . and again :
could some one explain how it works...
see all is starting from root directory,
how : is used and . is used here.
The : is simply a separator for the paths. The single dot "." is just setting the PATH variable to the directory where the user being logged in, stands.
ok if give
cd $PATH
to which path it will go
will give error, as $PATH will be expanded to /usr/bin:/usr/ucb:/etc:/usr/sbin:.:/usr/platform/sun4u/sbin and you will enter cd /usr/bin:/usr/ucb:/etc:/usr/sbin:.:/usr/platform/sun4u/sbin
on the system.
yeah i got it.
then how the variable PATH to be used?
Well, PATH is your PATH.
So if you run a command, your shell will search through the PATH variable. Each value, remember the : to be a field separator, stands for a directory. So, the shell searches for the command in those directories. The first hit is used.
Your PATH begins with /usr/bin so if you type ls and ls is in /usr/bin, shell will execute that. If it's not there, shell will check /usr/ucb. etc.
yeah fine.
Thanks.