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arithmetic in ksh

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# 8  
Old 01-30-2007
Quote:
Originally Posted by d.f.
Isn't this the "preferred" way of doing arithmetic in ksh and bash? I recall reading that it doesn't spawn a new shell like expr and bc.
Yes,
but for floating point arithmetic you need bc or awk.
# 9  
Old 02-03-2007
Just for giggles, here is a way of doing integer division with rounding resulting in a floating point quotient.

Code:
#!/bin/ksh

    typeset -Z3     PRC=0 DEC=0
    integer         INT=0

    integer         CATCH=14
    integer         NUM=100


    (( INT = ( ( ( CATCH * 1${PRC}0 ) / NUM ) + 5 ) / 10 ))

    (( DEC = $INT % 1${PRC} ))
    (( INT /= 1$PRC ))

    echo "$CATCH / $NUM = $INT.$DEC"

which produces
14 / 100 = 0.140

The precision is controlled by the number of leading zeros in the typeset -Z# line. It is cumbersome but preserves leading zeros in the decimal portion.
Last edited by hegemaro; 02-09-2007 at 10:35 AM.. Reason: correct alorithm
# 10  
Old 02-03-2007
Also, most version of unix supply ksh88. But with ksh95, you can do floating point arithimetic in ksh. "float" is alias for "typeset -E" (which actually uses the C language double precision arithmetic). I hope the various vendors will upgrade to ksh95 someday.
# 11  
Old 02-04-2007
Quote:
Originally Posted by Perderabo
Also, most version of unix supply ksh88. But with ksh95, you can do floating point arithimetic in ksh. "float" is alias for "typeset -E" (which actually uses the C language double precision arithmetic). I hope the various vendors will upgrade to ksh95 someday.
I think you mean ksh93.
# 12  
Old 02-04-2007
Opps...ksh93 it is... good catch.
# 13  
Old 02-05-2007
Guys..

Thanks for this wonderful explanation..I think this will be useful post!

Cheers,
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