Useful functions to have in a shell

functions.sh

# Load via:
# if [ -f "${HOME}/.functions.sh" ]; then . "${HOME}/.functions.sh"; fi
# MIT License

if [ "${PLATFORM}" = "Linux" ]; then
  alias pbcopy='xclip -selection clipboard'
  alias pbpaste='xclip -selection clipboard -o'
fi

function extract() {
    local c e i

    ((${#})) || return

    for i; do
        c=''
        e=1

        if [[ ! -r ${i} ]]; then
            echo "${0}: file is unreadable: \`${i}'" >&2
            continue
        fi

        case ${i} in
            *.t@(gz|lz|xz|b@(2|z?(2))|a@(z|r?(.@(Z|bz?(2)|gz|lzma|xz)))))
                   c=(bsdtar xvf);;
            *.7z)  c=(7z x);;
            *.Z)   c=(uncompress);;
            *.bz2) c=(bunzip2);;
            *.exe) c=(cabextract);;
            *.gz)  c=(gunzip);;
            *.rar) c=(unrar x);;
            *.xz)  c=(unxz);;
            *.zip) c=(unzip);;
            *)     echo "${0}: unrecognized file extension: \`${i}'" >&2
                   continue;;
        esac

        command "${c[@]}" "${i}"
        ((e = e || ${?}))
    done
    return "${e}"
}

function up() {
  if [[ "${#}" -lt 1 ]]; then
    cd ..
  else
    CDSTR=""
    for ((i=0; i<${1}; i++)); do
      CDSTR="../${CDSTR}"
    done
    cd "${CDSTR}" || return
  fi
}

function over() {
  if [[ "${#}" -lt 1 ]]; then
    up
  fi
  if [[ "${#}" -lt 2 ]]; then
    up
    cd "${1}"
  else
  # command count_up path_over
    up "${1}"
    cd "${2}"
  fi
}

function public_ip() {
  curl -w "\n" https://canihazip.com/s
}

function take() {
  mkdir -p "${@}" && cd "${@:$#}" || exit
}

function open_command() {
  local open_cmd

  # define the open command
  case "${OSTYPE}" in
    darwin*)  open_cmd='open' ;;
    cygwin*)  open_cmd='cygstart' ;;
    linux*)   [[ "$(uname -r)" != *icrosoft* ]] && open_cmd='nohup xdg-open' || {
                open_cmd='cmd.exe /c start ""'
                [[ -e "$1" ]] && { 1="$(wslpath -w "${1:a}")" || return 1 }
              } ;;
    msys*)    open_cmd='start ""' ;;
    *)        echo "Platform $OSTYPE not supported"
              return 1
              ;;
  esac

  ${=open_cmd} "$@" &>/dev/null
}