shell arithmetic operations

[andi_1]

Hi guys,

tmp=$extra/100
echo "tmp is $tmp" // displayes 10/100

I also tried the following:
tmp=`expr $extra / 100` // same thing

Does anyone know the best way to perform arithmetic operations in shell?

Thank you.

[Frederic Sevestre · Accepted solution]

hi,

try
let tmp=extra/100

It should work,
Fr??d??ric

[Francois Bariselle_3]

In C-shell:

set num1 = 8
set num2 = 2

@ num = ( ${num1} / ${num2} )
echo ${num}

result :

4

See :

man csh

Frank

[A. Clay Stephenson]

Try this:

A=300
B=10
C=$(( ${A} / ${B} ))
echo "C = ${C}"

Note: The shell does integer arithmetic.

[Deshpande Prashant]

Hi
Try this
TMP=100
TMP1=10

let TMP2=${TMP}/${TMP1}
echo $TMP2 will display 10

Thanks.
Prashant Deshpande.

[Kong Kian Chay]

Leon

* You should have a space before & after the arithmetic sign. Examples :

expr 4 + 3 (gives 7)
expr 4 / 2 (gives 2)
expr 4 \* 3 (gives 12)

[Deshpande Prashant]

Also Try

TMP=100
TMP1=10
((TMP2=TMP/TMP1))
echo $TMP2 will display 10

Thanks.
Prashant Deshpande.

[Roger Baptiste]

tmp=`echo $extra/100 | bc`
echo "tmp is $tmp"


-raj

[James R. Ferguson]

Hi Leon:

As already noted, the shell provides integer arithmetic. If you want to incorporate real numbers, 'bc' provides a convenient vehicle. Choose the 'scale' to set the precision you want:

# X=1;Y=8;echo "scale=3\n $X/$Y"|bc

You can also leverage 'awk' and couple it with 'printf' to format output in different number bases:

# X=1;Y=8;echo "$X $Y"|awk '{printf "%.4f\n",$1/$2}'

# X=7;Y=8;echo "$X $Y"|awk '{printf "%4x\n",$1+$2}'

Regards!

...JRF...

[Magdi KAMAL]

Hi Leon,

Here are the basic arithmetic operations :

1. Addition :
# expr 8 + 2
10

2. substraction :
# expr 8 - 2
6

3. Division :
# expr 8 / 2
4

4. Multiplication :
# expr 8 \* 2
16

Magdi