some pretty stupid roundabout bash

version_endpoints_compare.sh

# cross-platform bash-3.2 compatible (thanks macos)
#
# examples:
#
# $ version_endpoints_compare "3.7.1" "<=4.3.1" "=4.3.4" ">=4.3.5" ">=4.4"
# <=4.3.1
# $ version_endpoints_compare "4.3.1" "<=4.3.1" "=4.3.4" ">=4.3.5" ">=4.4"
# <=4.3.1
# $ version_endpoints_compare "4.3.2" "<=4.3.1" "=4.3.4" ">=4.3.5" ">=4.4"
# other
# $ version_endpoints_compare "4.3.3" "<=4.3.1" "=4.3.4" ">=4.3.5" ">=4.4"
# other
# $ version_endpoints_compare "4.3.4" "<=4.3.1" "=4.3.4" ">=4.3.5" ">=4.4"
# =4.3.4
# $ version_endpoints_compare "4.3.5" "<=4.3.1" "=4.3.4" ">=4.3.5" ">=4.4"
# >=4.3.5
# $ version_endpoints_compare "4.3.7" "<=4.3.1" "=4.3.4" ">=4.3.5" ">=4.4"
# >=4.3.5
# $ version_endpoints_compare "4.4.0" "<=4.3.1" "=4.3.4" ">=4.3.5" ">=4.4"
# >=4.4
# $ version_endpoints_compare "5.2.1" "<=4.3.1" "=4.3.4" ">=4.3.5" ">=4.4"
# >=4.4
# >=4.4

# or without an equals condition:
# $ version_endpoints_compare "4.3.1" "<=4.3.1" ">=4.3.5" ">=4.4"
# "<=4.3.1"
# $ version_endpoints_compare "4.3.4" "<=4.3.1" ">=4.3.5" ">=4.4"
# other
# $ version_endpoints_compare "4.3.5" "<=4.3.1" ">=4.3.5" ">=4.4"
# >=4.3.5
#
#
# as currently written only supports one equals condtion
#
#
# Intended usage pattern is like
#
# case version_endpoints_compare "$version" "<=4.3.1" ">=4.3.5" ">=4.4" in 
#  <=4.3.1) 
#    .... ;;
#  other) ... ;;

fail() {
  echo -e "\e[31mFail:\e[m $*"
  exit 1
}

version_endpoints_compare() {
  local input_verson;
  input_version="$1"; 
  shift;
  local input_line_included=""
  
  local constraint_sort_lines=()
  local constraints=()
  
  for c in "$@"; do 
    if [[ "$c" =~ ^"<=" ]]; then
      constraint_sort_lines+=("${c#<=*}C")
      constraints+=("$c")
    elif [[ "$c" =~ ^"=" ]]; then
      constraint_sort_lines+=("${c#=*}A")
      if [[ -z "$input_line_included" ]]; then
        constraint_sort_lines+=("${input_version}B input_version")
        constraints+=("other")
        input_line_included="yes"
      fi
      constraints+=("$c")
    elif [[ "$c" =~ ^">=" ]]; then
      if [[ -z "$input_line_included" ]]; then
        constraint_sort_lines+=("${input_version}B input_version")
        constraints+=("other")
        input_line_included="yes"
      fi
      constraint_sort_lines+=("${c#>=*}")
      constraints+=("$c")
    else
      fail "Unrecognized constraint: '$c'. Should start with <=, =, or >=";
    fi
  done

  line_after_sort=$(printf "%s\n" "${constraint_sort_lines[@]}" | sort --version-sort | \
    grep --line-number "input_version" | cut -f1 -d: )

  echo "${constraints[line_after_sort - 1]}"
}