43 lines
540 B
Bash
43 lines
540 B
Bash
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#!/bin/sh
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# Unix Shell version of a Prime Number Finder
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# haplo@mindstab.net
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odd=3
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sqr=4
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max=2
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i=3
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if [ ! $1 ] ; then
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echo "primes.sh [Max number]"
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exit
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fi
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MAX=$1
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if [ $MAX -le 0 ] ; then
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echo "Max must be a valid number"
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exit
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fi
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while [ $i -lt $MAX ] ;
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do
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isP=1
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x=3
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while [ $x -le $max -a $isP != 0 ] ;
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do
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isP=`expr $i % $x`
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x=`expr $x + 2`
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done
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if [ $isP != 0 ] ;
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then
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echo "$i"
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fi
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if [ $i -ge $sqr ] ;
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then
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max=`expr $max + 1`
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odd=`expr $odd + 2`
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sqr=`expr $odd + $sqr - 2`
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fi
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i=`expr $i + 2`;
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done
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