Any one can explain this？

[okyour]

thanks

bcdb-p03:/script_file/OS#de_percent=$(( 47816844 * 10 ))
bcdb-p03:/script_file/OS#echo $de_percent
478168440
bcdb-p03:/script_file/OS#de_percent=$(( 47816844 * 100 ))
bcdb-p03:/script_file/OS#echo $de_percent
486717104

[Ralph Grothe]

Probably owe to overrun.
I think the shell arithmetics only can handle 2^31 as maximum integer value (I think one bit is required for the sign)
The man page should mention the limitations.
You could resort to bc or perl, python for big ints.

[Peter Nikitka]

Hi,

A slight overrun will lead to negative numbers.
Now remember, that a '-' may be interpreted by the 'echo' or 'print' as an option.

My Sun ksh (64Bit) tells:

print $((47816844 * 100000000000))
4781684400000000000
print $((47816844 * 1000000000000))

print -- "$((47816844 * 1000000000000))"
-7523388221128654848

mfG Peter

[okyour]

Hi

Thanks for the reply. but how can I resolve this question,I need to write a script like this to check the memory treadhold,but if the memory is large,the script will get wrong result.plz give me further help

########### check memory added 09/04/2007

thresholdmem=10
de_phy=`more /var/adm/syslog/syslog.log|grep -i phy|grep available|awk '{print $7}'`
de_free=`more $State_File |grep Memory:|awk '{print $8}'|sed 's/K//p'`
de_percent=$(( $de_free * 100 / $de_phy ))

if [ $thresholdmem -gt $de_percent ]

then
echo "Current free Memory is : $de_percent %" >> $output_file
echo "Critical: Found that there is Memory issue! plz check it ASAP!!\n" >> $output_file
grep -i USERNAME $State_File >> $output_file

typeset i=1
while read -r yy
do
if [ $i -gt 15 ]
then
printf "%s \n" "$yy" >> $State_File2
fi

if [ $i -gt 1115 ]
then
break
fi
let i=i+1
done < $State_File

sort -r -k 8,8 $State_File2 >> $new_file2

typeset a=1
while read -r xx
do
if [ $a -gt 0 ]
then
printf "%s \n" "$xx" >> $output_file
fi

if [ $a -gt 20 ]
then
break
fi
let a=a+1
done < $new_file2

[Peter Nikitka · Accepted solution]

Hi,

first choice:
come to lower numbers, in computing the values you use not in KB but MB - so you have a factor of 1/1024.

Another alternative would be the use of dc/awk/perl to get 64Bit integer arithmetik or floating point calculation.
E.G.
print "47816844 100*p" | dc

mfG Peter

[okyour]

Problem solved