1

Possible Duplicate:
$VAR vs ${VAR} and to quote or not to quote

I assigned a variable var a value as follows:

pradeep@pradeep-laptop:~$ var="Pradeep
> is     
> a good
> boy"

Then I issued a echo command as:

pradeep@pradeep-laptop:~$ echo $var
Pradeep is a good boy

and for the command:

pradeep@pradeep-laptop:~$ echo "$var"
Pradeep
is 
a good
boy

I want to know why there is difference in the output?

Community
  • 1
pradeepchhetri
  • 9,959

1 Answers1

4

Expansions that occur within double quotes (") do not undergo field splitting.

In echo $var, since the expansion of $var does not occur within double-quotes, so it does undergo splitting. The shell runs echo with the 5 arguments: Pradeep, is, a, good, boy. echo prints all of its arguments separated with a space.

In echo "$var", the expansion of $var occurs within double-quotes, so it does not undergo splitting. The shell runs echo with a single argument, 

Pradeep
is
a good
boy

which echo faithfully prints.

jw013
  • 51,212