Shell Scripting

Shell Scripting RSS

integer division! oh the fun :-)

Thread Solved

•

Join Date: Feb 2006

Posts: 399

Reputation: chris5126 is an unknown quantity at this point

Solved Threads: 14

chris5126

Offline

Posting Whiz

integer division! oh the fun :-)

Dec 7th, 2008

Hi guys,

Will keep this short and sweet. Trying to do integer devision to *decimial places but i dont think the version of ksh installed on solaris 10 supports this as they would need to be declared as floats. Is this correct?

If there isnt a way of doing it with ksh is there another way to do it

 Help with Code Tags 
 Shell Scripting Syntax (Toggle Plain Text) 
 integer rBytes=`kstat -p -c net -n $Interface -s rbytes64 1 2 |\
                tail -1 | awk '{print $2}'`
  integer oBytes=`kstat -p -c net -n $Interface -s obytes64 1 2 |\
                tail -1 | awk '{print $2}'`
  integer read=$(($rBytes/1000000))
  integer write=$(($oBytes/1000000))
  k=k+1
  echo "rBytes=$rBytes oBytes=$oBytes"
  echo "read=$read Mbps write=$write Mbps"
 integer rBytes=`kstat -p -c net -n $Interface -s rbytes64 1 2 |\
                tail -1 | awk '{print $2}'`
  integer oBytes=`kstat -p -c net -n $Interface -s obytes64 1 2 |\
                tail -1 | awk '{print $2}'`
  integer read=$(($rBytes/1000000))
  integer write=$(($oBytes/1000000))
  k=k+1
  echo "rBytes=$rBytes oBytes=$oBytes"
  echo "read=$read Mbps write=$write Mbps"

Gives the output:

 Help with Code Tags 
 Shell Scripting Syntax (Toggle Plain Text) 
rBytes=694127 oBytes=769020
read=0 Mbps write=0 Mbps
rBytes=17061 oBytes=141840
read=0 Mbps write=0 Mbps
rBytes=694127 oBytes=769020
read=0 Mbps write=0 Mbps
rBytes=17061 oBytes=141840
read=0 Mbps write=0 Mbps

Whereas it should give:

 Help with Code Tags 
 Shell Scripting Syntax (Toggle Plain Text) 
rBytes=694127 oBytes=769020
read=0.69 Mbps write=0.76 Mbps
rBytes=17061 oBytes=141840
read=0.17 Mbps write=0.14 Mbps
rBytes=694127 oBytes=769020
read=0.69 Mbps write=0.76 Mbps
rBytes=17061 oBytes=141840
read=0.17 Mbps write=0.14 Mbps

Last edited by chris5126; Dec 7th, 2008 at 11:59 am.

If my post helped add to my rep!

•

Join Date: Dec 2005

Posts: 5,850

Reputation: Salem has a reputation beyond repute

Solved Threads: 749

Salem

Offline

Void main'ers are DOOMed

Re: integer division! oh the fun :-)

Dec 7th, 2008

Personally, I would just do
awk '{print $2 / 1000000 }'
and stop worrying about just how good the maths is in the shell.

Also, awk has printf() as well, so you've got really good control over the format as well.

•

Join Date: Feb 2006

Posts: 399

Reputation: chris5126 is an unknown quantity at this point

Solved Threads: 14

chris5126

Offline

Posting Whiz

Re: integer division! oh the fun :-)

Dec 7th, 2008

ok not to familar with awk had a little play but getting errors. So if i wanted to manipluate the varialbes and then put them into the new varialbles read and write how would i do it. Also would be good if you could show me how to do it to two decimal places.

 Help with Code Tags 
 Shell Scripting Syntax (Toggle Plain Text) 
 Interface=`cat $Interfaces | sed -n $k"p"`
  integer rBytes=`kstat -p -c net -n $Interface -s rbytes64 1 2 |\
                tail -1 | awk '{print $2}'`
  awk '{print $rBytes / 100000}'END
  integer oBytes=`kstat -p -c net -n $Interface -s obytes64 1 2 |\
                tail -1 | awk '{print $2}'`
  #integer read=$(($rBytes/1000000))
  #integer write=$(($oBytes/1000000))
  k=k+1
  echo "rBytes=$rBytes oBytes=$oBytes"
 Interface=`cat $Interfaces | sed -n $k"p"`
  integer rBytes=`kstat -p -c net -n $Interface -s rbytes64 1 2 |\
                tail -1 | awk '{print $2}'`
  awk '{print $rBytes / 100000}'END
  integer oBytes=`kstat -p -c net -n $Interface -s obytes64 1 2 |\
                tail -1 | awk '{print $2}'`
  #integer read=$(($rBytes/1000000))
  #integer write=$(($oBytes/1000000))
  k=k+1
  echo "rBytes=$rBytes oBytes=$oBytes"

If my post helped add to my rep!

•

Join Date: Dec 2005

Posts: 5,850

Reputation: Salem has a reputation beyond repute

Solved Threads: 749

Salem

Offline

Void main'ers are DOOMed

Re: integer division! oh the fun :-)

Dec 7th, 2008

> awk '{print $rBytes / 100000}'END
How is that anything like what I posted?

•

Join Date: Feb 2006

Posts: 399

Reputation: chris5126 is an unknown quantity at this point

Solved Threads: 14

chris5126

Offline

Posting Whiz

Re: integer division! oh the fun :-)

Dec 7th, 2008

haha i was trying to put the value into a varailble and was getting frusturtated and trying different things! thanks for your help!

If my post helped add to my rep!

•

Join Date: Oct 2007

Posts: 399

Reputation: eggi will become famous soon enough

Solved Threads: 47

eggi

Offline

Posting Whiz

Re: integer division! oh the fun :-)

Dec 8th, 2008

Hey there,

One way to pass variables to awk (so you don't have to use double quotes) is with the -v flag, like

•

awk -v rBytes1=$rBytes '{......blah,blah,blah...}'

and then you could use the variable rBytes1 in your script just like any other awk variable.

Best wishes,

Mike

Linux and Unix Tips, Tricks and Individual Advice - The Linux and Unix Menagerie!
------------------------------------------------------------------------
The greatest viral marketing idea of all time, get your copy of this Free Report now!

•

Join Date: Aug 2007

Posts: 165

Reputation: Fest3er is an unknown quantity at this point

Solved Threads: 18

Fest3er

Offline

Junior Poster

Re: integer division! oh the fun :-)

Dec 12th, 2008

bc(1) is your friend. It computes to arbitrary precision.

"-e" tells bash to interpret \x sequences; ksh might not need it.

 Help with Code Tags 
 Shell Scripting Syntax (Toggle Plain Text) 
  .
  .
  .
  integer read=`echo -e "scale=2\n$rBytes/1000000" | bc`
  integer write=`echo -e "scale=2\n$wBytes/1000000" | bc`
  .
  .
  .
  .
  .
  .
  integer read=`echo -e "scale=2\n$rBytes/1000000" | bc`
  integer write=`echo -e "scale=2\n$wBytes/1000000" | bc`
  .
  .
  .