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# shellcheck shell=bash
# sortArray
# Sorts the indexed array referenced by inputArrRef and stores the result in the indexed array referenced by
# outputArrRef.
#
# Arguments:
# - inputArrRef: a reference to an indexed array (not mutated, may alias outputArrRef)
# - outputArrRef: a reference to an indexed array (contents are replaced entirely, may alias inputArrRef)
#
# Returns 0.
sortArray() {
if (($# != 2)); then
nixErrorLog "expected two arguments!"
nixErrorLog "usage: sortArray inputArrRef outputArrRef"
exit 1
fi
local -rn inputArrRef="$1"
local -rn outputArrRef="$2"
if ! isDeclaredArray "${!inputArrRef}"; then
nixErrorLog "first argument inputArrRef must be a reference to an indexed array"
exit 1
elif ! isDeclaredArray "${!outputArrRef}"; then
nixErrorLog "second argument outputArrRef must be a reference to an indexed array"
exit 1
fi
local -a sortedArray=()
# Guard on the length of the input array, as empty array will expand to nothing, but printf will still see it as an
# argument, producing an empty string.
if ((${#inputArrRef[@]} > 0)); then
# NOTE from Bash's printf documentation:
# The format is reused as necessary to consume all of the arguments. If the format requires more arguments than
# are supplied, the extra format specifications behave as if a zero value or null string, as appropriate, had
# been supplied.
# - https://www.gnu.org/software/bash/manual/html_node/Bash-Builtins.html#index-printf
# NOTE from sort manpage:
# If you use a non-POSIX locale (e.g., by setting LC_ALL to 'en_US'), then sort may produce output that is sorted
# differently than you're accustomed to. In that case, set the LC_ALL environment variable to 'C'. Setting only
# LC_COLLATE has two problems. First, it is ineffective if LC_ALL is also set. Second, it has undefined behavior
# if LC_CTYPE (or LANG, if LC_CTYPE is unset) is set to an incompatible value. For example, you get undefined
# behavior if LC_CTYPE is ja_JP.PCK but LC_COLLATE is en_US.UTF-8.
# - https://www.gnu.org/software/coreutils/manual/html_node/sort-invocation.html#FOOT1
mapfile -d $'\0' -t sortedArray < <(printf '%s\0' "${inputArrRef[@]}" | LC_ALL=C sort --stable --zero-terminated)
fi
outputArrRef=("${sortedArray[@]}")
return 0
}
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