String Concantenation Problem 2

[Michael42]

Hello,

In creating a Bourne shell script I can easily set a variable using the below:

VAR1="A"
VAR2="B"
VAR3="$VAR1.$VAR2"
echo $VAR3

Output: [b][COLOR=blue]A.B[/color][/b]

The problem I am having is when I try to use an underscore. The below does not work:

VAR1="A"
VAR2="B"
VAR3="$VAR1_$VAR2"
echo $VAR3

Output: [b][COLOR=blue]B[/color][/b]

Desired output: A_B

How can I use an underscore in a variable value when concantenatiing two together?

Thanks,

Michael42

 

[p5wizard]

Use braces around var names:

VAR3="${VAR1}_${VAR2}"


_ is also a valid character in a var name, so your script was looking for the value of var VAR1_, which resulted in a null string.



HTH,

p5wizard

 

[PHV]

VAR3="${VAR1}_$VAR2"

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ181-2886

 

[Michael42]

Thanks guys - you always have the answer. I have seen the curly brackets used but never understood them until now.