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perform echo and awk inside a string

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# 1  
Old 02-08-2012
perform echo and awk inside a string
hi,

just wanted to make a shortcut of this one
a="a b c"
b=`echo $a | awk '{print $2}'`
echo "the middle is $b"


why can't i do this:
a="a b c"
echo "the middle is ${`echo $a | awk '{print $2}'`}" <- bad substitution Smilie

thanks
# 2  
Old 02-08-2012
Code:
echo "the middle is `echo $a | awk '{print $2}'`"

This User Gave Thanks to balajesuri For This Post:
h0ujun
# 3  
Old 02-08-2012
Quote:
Originally Posted by h0ujun
hi,

just wanted to make a shortcut of this one
a="a b c"
b=`echo $a | awk '{print $2}'`
echo "the middle is $b"


why can't i do this:
a="a b c"
echo "the middle is ${`echo $a | awk '{print $2}'`}" <- bad substitution Smilie

thanks
It should be:

Code:
 
a="a b c"
echo "the middle is $(echo $a | awk '{print $2}')"

[PS: U should keep your Codes/Output in CODE Tag. Mods don't like unformatted codes and output. SO next time please use Code Tags]
# 4  
Old 02-08-2012
Either way is fine. Backticks are used in post #2.. $() will work equally well.
# 5  
Old 02-08-2012
Quote:
Originally Posted by balajesuri
Either way is fine. Backticks are used in post #2.. $() will work equally well.

Oopps... We both posted nearly at the same time so did not see ur reply :P
I like $() more then `` because of aeshetic value and less confusion over `` and '' Smilie
# 6  
Old 02-08-2012
Quote:
Originally Posted by knight_eon
[..]
I like $() more then `` because of aeshetic value and less confusion over `` and '' Smilie
Plus in the backquote style command substitution you sometimes need to escape certain things (for example when nesting) whereas in $() this is much more straightforward..
# 7  
Old 02-08-2012
Plus, backticks is obsolete, $( ) is recommended.

--ahamed
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