Question

I have seen below two lines in a shell script.
Im new to unix scripting, what is the use of setting this?

PATH=$PATH:/bin:/usr/bin:/usr/sbin:/sbin:/etc:/usr/ucb:/usr/ccs/bin:/usr/local/bin
export PATH

Thanks in advance

Answer 1

If you export something (in bash anyway which I assume is your shell), it will mark that something to be available in subsequently executed commands.

$ FOO=1 # Set the variable
$ echo $FOO # Check the value
1
$ bash # New shell here. 

$ echo $FOO # No value since it's not exported

$ exit # Quit the subshell
$ export FOO # Export it
$ bash
$ echo $FOO # It has a value now
1

export is a shell builtin for bash so doing a help export will give you more information on it.