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Storing the output into a variable

 
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# 1  
Old 12-08-2006
Storing the output into a variable
Hi unix gurus,

I am trying to store the result of a command into a variable.
But it is not getting stored.

x='hello'
y=echo $x | wc -c

but it is giving the output as 0(zero)

Pls help me its very urgent
# 2  
Old 12-08-2006
Code:
x='hello'
y=$(echo $x | wc -c)

# 3  
Old 12-08-2006
Smilie Ok,fine .Its working.But when i am trying to use the result in another calculation its not giving the proper result.
x='hello'
y=$(echo $x | wc -c)
echo $y
z='expr $y + 1 '
echo $z

Its printing expr $y + 1 instead of 7. Smilie

any idea pls.



cheers
Ravi Raj kumar
# 4  
Old 12-08-2006
can you try back quotes instead

Code:
z=`expr $y + 1`

# 5  
Old 12-08-2006
Smilie
Thank u so much boss.Its working now fine.




Thanks a lot.








cheers
Ravi raj kumar
# 6  
Old 12-08-2006
You need to understand the difference between

y=$(echo $x | wc -c)
and
z='expr $y + 1 '

In y=$(echo $x | wc -c), the output of the command echo $x | wc -c is stored into y. It is known as command substitution. You can do a command substitution in two ways. Either use $(...) or `...`

In z='expr $y + 1', the string expr $y + 1 is stored in z without any literal expansion.
# 7  
Old 12-08-2006
Quote:
Originally Posted by ravi raj kumar
Smilie Ok,fine .Its working.But when i am trying to use the result in another calculation its not giving the proper result.
x='hello'
y=$(echo $x | wc -c)
echo $y
z='expr $y + 1 '
echo $z

Its printing expr $y + 1 instead of 7. Smilie

any idea pls.



cheers
Ravi Raj kumar
The script works if you have the correct quote marks around the z='expr $y + 1 '. It is not the single quote ' but the backward quote` very important! I have tested it just to make sure!!!
 
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