シェルコマンドの意味を説明してくれるコマンド

シェルコマンドの複雑なオプションを簡単に説明してくれるコマンドの紹介。

Explaining Shell Commands in the Shell
同じ様なウェブサービス: explainshell.com

Explaining Shell Commands in the Shell

Explaining Shell Commands in the Shell ManKier Blog

上で紹介されてるスクリプトですが

explain.sh

# Add this to ~/.bash_profile or ~/.bashrc
explain () {
  if [ "$#" -eq 0 ]; then
    while read  -p "Command: " cmd; do
      curl -Gs "https://www.mankier.com/api/v2/explain/?cols="$(tput cols) --data-urlencode "q=$cmd"
    done
    echo "Bye!"
  elif [ "$#" -eq 1 ]; then
    curl -Gs "https://www.mankier.com/api/v2/explain/?cols="$(tput cols) --data-urlencode "q=$1"
  else
    echo "Usage"
    echo "explain                  interactive mode."
    echo "explain 'cmd -o | ...'   one quoted command to explain it."
  fi
}

# Update 26-03-2015. If using this command gives no output, see if running a simple fetch causes this error:
# $ curl https://www.mankier.com
# curl: (35) Cannot communicate securely with peer: no common encryption algorithm(s).
# If so, try specifying a cipher in the curl commands: curl --ciphers ecdhe_ecdsa_aes_128_sha

Explaining Shell Commands in Bash

この様な関数を作っておくと

$ explain 'du -s * | sort -n | tail'

du(1)
  Summarize disk usage of the set of FILEs, recursively for directories. Mandatory arguments to long
  options are mandatory for short options too.

  -s (-s, --summarize)
    display only a total for each argument

  *

-------------------------------------------------------------------------------------------------pipe--

sort(1)
  Write sorted concatenation of all FILE(s) to standard output. With no FILE, or when FILE is -, read
  standard input. Mandatory arguments to long options are mandatory for short options too.

  -n (-n, --numeric-sort)
    compare according to string numerical value

-------------------------------------------------------------------------------------------------pipe--

tail(1)
  Print the last 10 lines of each FILE to standard output. With more than one FILE, precede each with a
  header giving the file name. With no FILE, or when FILE is -, read standard input. Mandatory
  arguments to long options are mandatory for short options too.

$

こんな感じで各コマンドやオプションを説明してくれます。

これは、explainコマンドの中で、 ManKier Man Pages というサービスのAPIを使って説明を取ってきています。

なのでオンラインでのみ使えます。