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check a list of vars

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# 1  
Old 09-17-2008
check a list of vars
I have about 20 different variables that I need to check for null values then replace with a specific string if they are null. I've been doing this via 20 different if then statements like this:

Code:
if [ "$VAR1" = "" ]; then
WIND="UUU"
fi

Is there a more elegant way to do this? The vars aren't sequential in their name by the way. Thanks for the suggestions as always!
# 2  
Old 09-17-2008
Quote:
Originally Posted by audiophile
The vars aren't sequential in their name by the way.
I don't think you have any other choice.

Regards
# 3  
Old 09-17-2008
It's not clear what you are replacing but perhaps echo ${VAR1-UUU} and other shell variable substitution mechanisms would help here.
# 4  
Old 09-17-2008
Check if your shell supports the below syntax:

Quote:
${parameter:=word}
Assign Default Values. If parameter is unset or null, the
expansion of word is assigned to parameter. The value of
parameter is then substituted. Positional parameters and spe‐
cial parameters may not be assigned to in this way.
# 5  
Old 09-17-2008
Thanks for the replies, all. I'm using BASH for this script. That ${parameter:=word} syntax is foreign to me...
# 6  
Old 09-17-2008
Quote:
Originally Posted by audiophile
Thanks for the replies, all. I'm using BASH for this script. That ${parameter:=word} syntax is foreign to me...

That's a basic parameter expansion available in all Bourne-type shells (which includes bash and ksh).

Code:
: ${var1:=UUU} ${othervar:=XXX} ${myvar:=MEMEME}

# 7  
Old 09-18-2008
Thanks for the info, all. It works very well and in a single line of code!
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