18 lines
486 B
Bash
Executable File
18 lines
486 B
Bash
Executable File
#!/bin/bash
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if ! [[ "$1" =~ ^[0-9]+$ ]]; then
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echo "Usage: randint <positive integer>"
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exit 1
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fi
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number=$1
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ceiling=$(echo "l($number +1)/l(2)" | bc -l | awk '{
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bits = ($1 == int($1)) ? $1 : int($1) + 1;
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print int( (bits + 7) / 8 )
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}')
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random_num=$(xxd -p -l $ceiling /dev/urandom | tr -d '\n' | \
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awk -v max="$number" -v scale="$ceiling" '{
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val = strtonum("0x" $0);
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range = 2**(scale*8);
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print int(val * max / range)
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}')
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echo $random_num
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