问对于grep是否有一个优雅的正则表达式，一个包含各种分隔符的MAC地址？

EN

mac='56:ea:b6:a6:82:5e'

# Compose a regex on-the fly by replacing all colons with [:.-]?
grep -iE "${mac//:/[:.-]?}"

grepmac() {
  # Usage:
  # grepmac MAC_ADDRESS FILE [FILE]...

  # Parses input argument 1 as mac-address
  # regardless if it uses delimiters or not.
  # Returns failure if input argument 1 is not a mac-address.
  [[ $1 =~ ([[:xdigit:]]{2})[:.-]?([[:xdigit:]]{2})[:.-]?([[:xdigit:]]{2})[:.-]?([[:xdigit:]]{2})[:.-]?([[:xdigit:]]{2})[:.-]?([[:xdigit:]]{2}) ]] || return 1

  # Sets delimiter locally to : to join matches with colon
  local -- IFS=:
  # Joins matches except first to get a colon-delimited mac-address
  mac="${BASH_REMATCH[*]:1}"

  # Shifts out first argument away to only keep remaining file paths
  shift

  # Composes a regex by replacing colons in mac-address by [:.-]?
  # which matches optional delimiter with : . or - 
  regex=${mac//:/[:.-]?}

  # Performs the actual search
  grep -iE "$regex" "$@"
}

$ set -x; grepmac 56eab6a6825e

+ grepmac 56eab6a6825e
+ [[ 56eab6a6825e =~ ([[:xdigit:]]{2})[:.-]?([[:xdigit:]]{2})[:.-]?([[:xdigit:]]{2})[:.-]?([[:xdigit:]]{2})[:.-]?([[:xdigit:]]{2})[:.-]?([[:xdigit:]]{2}) ]]
+ IFS=:
+ mac=56:ea:b6:a6:82:5e
+ shift
+ regex='56[:.-]?ea[:.-]?b6[:.-]?a6[:.-]?82[:.-]?5e'
+ grep --color=auto -iE '56[:.-]?ea[:.-]?b6[:.-]?a6[:.-]?82[:.-]?5e'

grep-mac() {
    local mac="$1"
    local files=("${@:2}")

    # Strip punctuation from the input MAC.
    mac="${mac//[^[:alnum:]]}"
    # Create a regex by inserting `[:-\.]?` in between every two characters.
    local regex="${mac:0:2}$(sed -E 's/../[:-\\.]?\0/g' <<< "${mac:2}")"

    # Call `grep` with the regex and files we were passed.
    grep -iE "$regex" "${files[@]}"
}

❯ grep-mac 56:ea:b6:a6:82:5e syslog.log | less
❯ grep-mac 56EAB6A6825E syslog.log | less

$ grep -Ei '56[[:alnum:]:.-]+5e' <(less syslog.log)