All those SE trash

sorttime.bash

#!/bin/bash
n=${1:-1024} TIMEFORMAT=$'real\t%3lR\nuser\t%3lU\nsys\t%3lS\n'
echo "Testing performance on $n random elements... Filling array."
time while ((n--)); do to_sort+=($RANDOM); done
# http://unix.stackexchange.com/a/247659/73443
ul_bub () {
    for ((i=0; i <= $((${#arr[@]} - 2)); ++i))
    do
        for ((j=((i + 1)); j <= ((${#arr[@]} - 1)); ++j))
        do
            if [[ ${arr[i]} -gt ${arr[j]} ]]
            then
                # echo $i $j ${arr[i]} ${arr[j]}
                tmp=${arr[i]}
                arr[i]=${arr[j]}
                arr[j]=$tmp         
            fi
        done
    done
}
echo >&2 ul_bub
arr=("${to_sort[@]}")
time ul_bub
# http://unix.stackexchange.com/a/247660/73443
sortnums(){
    local OLDPWD IFS=' /'
    cd -- "$(mktemp -d)" || return
    touch -- $*; ls -A >/dev/null
    cd - >/dev/null &&
    rm -rf -- "$OLDPWD"
}
echo >&2 touch_and_ls
time (sortnums "${to_sort[@]}")
# http://unix.stackexchange.com/a/248137/73443
echo >&2 index_sort
(
  time {
    declare -A tmp
    for i in "${to_sort[@]}"; do (( tmp[$i]++ )); done
    # This eats duplicates.
    sorted_nodup=( "${!tmp[@]}" )
  }
  echo >&2 '.. expand_dup (add this to the calculation if you want all elements back)'
  time {
    for i in "${!tmp[@]}"; do
      j=${tmp[$i]}
      while ((j--)); do sorted+=("$i"); done
    done
  }
)
# http://unix.stackexchange.com/a/248145/73443
ext_sort_44() for array do
  readarray -tf '' "$array" < <(
    eval "printf '%s\0' \"\${$array[@]}\" | sort -zg")
done
echo >&2 ext_sort_44
arr=("${to_sort[@]}")
time ext_sort_44 arr
ext_sort() for array do
  tmp=() i=0
  while IFS= read -rd '' "tmp[i++]"; do :; done < <(
    eval "printf '%s\0' \"\${$array[@]}\" | sort -zg")
  eval "$array=("'"${tmp[@]}")'
done
arr=("${to_sort[@]}")
time ext_sort arr

UL238582_linky.bash

#!/bin/bash
((!EUID)) || exec sudo "$0" "$@" # Addicted to OR-logic
declare -A src_dst_pair src_dst_old; # dictionaries -- the older one not being used
oops(){ printf '%b\n' "oOpsS!\t$1">&2; exit "${2:-1}"; }

## oldlist file
## Gets the contents of a legacy list.
oldlist() {
    local arr i s d;
    awk '/^#BEGIN-log#/ {flag=1; next} /^#END-log#/ {flag=0} flag' "$1" | mapfile arr
    for i in "${arr[@]}"; do
        case "$i" in *'=('*=*=*')') :;; *) continue;; esac
        i="${i#*(}"
        i="${i%)}"
        read s d <<< "$i"
        remember "${s#*=}" "${d#*=}" src_dst_old
    done
}

##remember key val <varname> Generates a basically safe-to-use line of script and appends it to self.
# TODO: write this back to a script.
remember() {
    printf '%s\n' "${3:-src_dst_pair}[$(printf %q "$1")]=$(printf %q "$2")" >> "$0"
}

try_link(){
    local SRC="$1" DST="$2" src_in_dst
    [[ -e "$SRC" ]] || [[ -e "$DST" ]] || oops "$DST"
    [[ -e "$SRC" ]] || mv "$DST" "$SRC"
    [[ -e "$DST" ]] || ln -Tsf "$SRC" "$DST"
    src_in_dst=("$DST"/*"$SRC"*)
    ((${#src_in_dst[@]})) || ln -Tsf "$SRC" "$DST"
}

# -> for thing in "$@"
for thing; do
    [[ $thing == /* ]] || thing="$PWD/$thing" # relative path, hmm.
    SRC=/.hd$thing DST=$thing
    [[ "$SRC $DST" != *'.hd/.hd'* ]] || oops 'pathdup: .hd/.hd'
    remember "$SRC" "$DST"
    try_link "$SRC" "$DST"
done

# Another way to spell eval "$(blah)"
source <(awk '/^# __DATA_START__/ { flag=1; next } flag')
for those in "${!src_dst_pair[@]}"; do try_link "$those" "${src_dst_pair[$those]}"; done
exit
# __DATA_START__