What am I doing wrong in this bash script ?

bashprog · 10-10-2010, 04:53 PM

Why am I getting "expr: non-numeric argument" here ?

I thought variables are not typed in bash.
If I initialize SIZE and TIME from command line the script works well.
Can you help ?

TIA

Code:

#!/bin/sh


report ()
{

echo $SIZE $TIME
RATE=`expr $1 / $2`
echo $RATE


}


i='1.00000,0.02012'



read SIZE TIME <<< `echo "$i" | cut -d , -f1-2 --output-delimiter=' '`

echo $SIZE $TIME

report $SIZE $TIME

bashprog · 10-10-2010, 05:17 PM

I don't want to use bc. What I am really curious to know is why am I getting this error in the first place. I thought variables are not typed in bash, and so I should not be getting this error.

bashprog · 10-10-2010, 05:52 PM

I know what am I doing wrong, I am doing floating point arithmetic with expr. Not supported.

Can I do floating point arithmetic without using bc ?

j1alu · 10-10-2010, 06:07 PM

I think the problem is:

Quote:

Bash does not understand floating point arithmetic. It treats numbers containing a decimal point as strings.

from here:
http://tldp.org/LDP/abs/html/ops.html (Example 8.2)

ups: we posted at the same time.

grail · 10-10-2010, 07:19 PM

Quote:

Can I do floating point arithmetic without using bc ?

Yes. Try awk or any of a dozen other scripting languages.