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Assigning bc output to a variable

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# 1  
Old 11-07-2013
Assigning bc output to a variable
I'm converting decimal to integer with bc, and I'd like to assign the integer output from bc to a variable 'val'.

E.g. In the code below: If b is 5000.000, lines 6 and 8 will output:
5000
(5000.000+0.5)/1 | bc

I'd like val to take the value 5000 though, rather than 5000.000

Does someone have any idea how to do that?
Code:
#! /bin/bash

while read b
do

    echo "($b+0.5)/1" | bc        # line 6 - works
    val= "($b+0.5)/1 | bc"        # line 7 - doesn't work
    echo $val                          # line 8

done < infile

Last edited by Franklin52; 11-07-2013 at 08:20 AM.. Reason: Please use code tags
# 2  
Old 11-07-2013
Quote:
Originally Posted by pina
I'm converting decimal to integer with bc, and I'd like to assign the integer output from bc to a variable 'val'.

E.g. In the code below: If b is 5000.000, lines 6 and 8 will output:
5000
(5000.000+0.5)/1 | bc

I'd like val to take the value 5000 though, rather than 5000.000

Does someone have any idea how to do that?


Try:
Code:
#! /bin/bash

while read b
do

    echo "($b+0.5)/1" | bc        # line 6 - works
    val=$(($b+0.5)/1 | bc)        # line 7 - should now work
    echo $val                          # line 8

done < infile

Basically $(...) invokes command substitution such that the output of command/subshell can be assigned to a variable.

Andrew
# 3  
Old 11-07-2013
Quote:
Originally Posted by apmcd47
Try:
Code:
#! /bin/bash

while read b
do

    echo "($b+0.5)/1" | bc        # line 6 - works
    val=$(($b+0.5)/1 | bc)        # line 7 - should now work
    echo $val                          # line 8

done < infile

Basically $(...) invokes command substitution such that the output of command/subshell can be assigned to a variable.

Andrew
@ apmcd47 your solution gives error

if ksh93 then this will work
Code:
val=$((b+0.5/1))

Try this for bash

Code:
$ b=5000
$ echo "($b+0.5)/1" | bc 
5000
$
$ variable=$(echo "($b+0.5)/1" | bc )
$ echo $variable
5000

if floating point is needed then try
Code:
$ var=$(echo "scale=1;$b+0.5/1" | bc) 
$ echo $var
5000.5

Last edited by Akshay Hegde; 11-07-2013 at 08:38 AM..
# 4  
Old 11-07-2013
Thanks, Akshay Hedge and Andrew!

This works nicely:
Code:
 variable=$(echo "($b+0.5)/1" | bc )

The command substitution didn't for some reason.
Last edited by pina; 11-07-2013 at 10:11 AM..
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