| 1 | #!/usr/bin/env bash
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| 2 | #
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| 3 | # Show superlinear behavior in bash arrays. Need pretty high N to start seeing
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| 4 | # it.
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| 5 | #
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| 6 | # Usage:
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| 7 | # ./array_ref.sh MODE
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| 8 |
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| 9 | set -o nounset
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| 10 | set -o pipefail
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| 11 | set -o errexit
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| 12 |
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| 13 | main() {
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| 14 | local mode=$1
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| 15 |
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| 16 | mapfile -t array
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| 17 |
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| 18 | local n=${#array[@]}
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| 19 | local sum=0
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| 20 |
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| 21 | case $mode in
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| 22 | linear)
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| 23 | for (( i = 0; i < n; ++i )); do
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| 24 | sum=$((sum + array[i]))
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| 25 | done
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| 26 | ;;
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| 27 |
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| 28 | random)
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| 29 | for (( i = 0; i < n; ++i )); do
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| 30 | # Super linear
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| 31 | sum=$((sum + array[array[i]]))
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| 32 | done
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| 33 | ;;
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| 34 | esac
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| 35 |
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| 36 | echo sum=$sum
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| 37 |
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| 38 | # This doesn't seem to defeat LASTREF?
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| 39 | #array+=('X')
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| 40 | #unset 'array[-1]'
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| 41 |
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| 42 | # neither does this
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| 43 | #array[i]=$i
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| 44 | }
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| 45 |
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| 46 | main "$@"
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