Ask HN: Share a shell script you like

- quickly opening my personal wiki: https://github.com/francium/dotfiles/blob/master/bin/.local/...

- re-run a script when a file changes: https://github.com/francium/dotfiles/blob/master/bin/.local/...

For `while-watchdo` you, you run it like `while-watchdo "echo hi"`, then in my editor, I have a custom shortcut that does `touch .watchfile` causing the command, in this case `echo hi` to run. I prefer this to tools that retrigger commands as soon as you save _any_ file. Also works in docker containers, edit a file on host, command runs in a container.

- https://github.com/koalaman/shellcheck

The author converted it to a vim plugin with the same name, but I use a different vim plugin implementation [mergetool].

[dc]: https://github.com/whiteinge/dotfiles/blob/master/bin/diffco... [mergetool]: https://github.com/idbrii/vim-mergetool

https://github.com/Magnushhoie/fuz

As a nice side-effect, I no longer worry about where I store text (e.g. with Obsidian), as I know I'll find it again if it's there. It helps using memorable keywords though.

https://developer.run/37

build() { ... }

run() { ... }

cmd="$1"

shift

$cmd "$@"

  # find2ra arrayName {find arguments...}
  # Run find command and put results in array arrayName.
  find2ra() {
    # (error checking removed)

    local -r f2raVar="${1}"
    shift
    # map find entries to ra, using char=0 as delimiter
    mapfile -d $'\0' -t "$f2raVar" < <(find -dsx "${@}" -print0)
    # -print0: handle paths with spaces, etc.
    # -ds: For consistency, use depth-first, lexigraphic order
    # -x: Avoid traversing other devices
  }

  # sample usage
  ra=()
  find2ra ra . -type f -name \*.sh
  for shFile in "${ra[@]}"; do ... ; done

The effort to document shell is also somewhat Pyrrhic. The benefit would be... more shell? A more modern shell?

Another goal might be to switch to a real language sooner. Go and Python are the obvious choices, but Swift and Java also support shebang's:

   #!/usr/bin/env swift

   #!/usr/bin/env java --source 17

  import PromiseKit  // @mxcl ~> 6.5

```

```

I wanted to link to a nice web page about the history of the (external) true command but google can't find anything anymore.

  #!/bin/bash
  cd "$(dirname "$0")"

    #!/usr/bin/zsh
    # Search a directory for files containing all of the given keywords.

    DIR=`mktemp -d`

    ROOT=${ROOT:-.}

    # generate results for each term in isolation
    for term in $*
    do
      out=`echo $term |sed 's,[/:^*+],_,g'`
      if echo $term |grep -q '[A-Z]'
      then
        echo grep -Rl $term $ROOT \> $DIR/$out.list >&2
        eval grep -Rl $term $ROOT > $DIR/$out.list
      else
        echo grep -Ril $term $ROOT \> $DIR/$out.list >&2
        eval grep -Ril $term $ROOT > $DIR/$out.list
      fi
    done

    # generate results containing all terms
    cat $DIR/*.list |sort |uniq -c |grep " $# " |column 2

    ccd() {
        mkdir -p $1
        cd $1
    }
    cdtemp() {
        cd $(mktemp -d)
    }

I also curate a shell command cheatsheet: https://github.com/fastily/cheatsheet

  run ()
  {
     ( exec "$@" < /dev/null > /dev/null 2>&1 & )
  }

It's probably my most used shell app. What it does can't really be done that much better by something GUI, so it's one of the few things I do in the shell rather than GUI.

normalize-audio is another one I like. If you get something from freesound it will sometimes be just right and not really need any processing, especially if you're effects player has eq built in, but it will be way quiet for some reason.

This script extracts URLs from a text input stream or text files using John Gruber's regular expressions. It requires GNU grep. If your system's default grep command isn't GNU, install ggrep and modify the script accordingly.

Save the script, make it executable, and try

  $ ./urls urls

  https://gist.github.com/gruber/249502
  https://gist.github.com/gruber/8891611

  urls [-w] [<grep arg> ...]

Source code:

  #! /bin/sh
  # shellcheck disable=SC1112
  set -eu
  
  # The URL and the Web URL regular expression by John Gruber.
  # https://gist.github.com/gruber/249502
  re_all='(?i)\b((?:[a-z][\w-]+:(?:/{1,3}|[a-z0-9%])|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}/)(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s`!()\[\]{};:'"'"'".,<>«»“”‘’]))'
  # https://gist.github.com/gruber/8891611
  re_web='(?i)\b((?:https?:(?:/{1,3}|[a-z0-9%])|[a-z0-9.\-]+[.](?:com|net|org|edu|gov|mil|aero|asia|biz|cat|coop|info|int|jobs|mobi|museum|name|post|pro|tel|travel|xxx|ac|ad|ae|af|ag|ai|al|am|an|ao|aq|ar|as|at|au|aw|ax|az|ba|bb|bd|be|bf|bg|bh|bi|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|cr|cs|cu|cv|cx|cy|cz|dd|de|dj|dk|dm|do|dz|ec|ee|eg|eh|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gg|gh|gi|gl|gm|gn|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|im|in|io|iq|ir|is|it|je|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|me|mg|mh|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|mv|mw|mx|my|mz|na|nc|ne|nf|ng|ni|nl|no|np|nr|nu|nz|om|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|ps|pt|pw|py|qa|re|ro|rs|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|Ja|sk|sl|sm|sn|so|sr|ss|st|su|sv|sx|sy|sz|tc|td|tf|tg|th|tj|tk|tl|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw)/)(?:[^\s()<>{}\[\]]+|\([^\s()]*?\([^\s()]+\)[^\s()]*?\)|\([^\s]+?\))+(?:\([^\s()]*?\([^\s()]+\)[^\s()]*?\)|\([^\s]+?\)|[^\s`!()\[\]{};:'"'"'".,<>?«»“”‘’])|(?:(?<!@)[a-z0-9]+(?:[.\-][a-z0-9]+)*[.](?:com|net|org|edu|gov|mil|aero|asia|biz|cat|coop|info|int|jobs|mobi|museum|name|post|pro|tel|travel|xxx|ac|ad|ae|af|ag|ai|al|am|an|ao|aq|ar|as|at|au|aw|ax|az|ba|bb|bd|be|bf|bg|bh|bi|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|cr|cs|cu|cv|cx|cy|cz|dd|de|dj|dk|dm|do|dz|ec|ee|eg|eh|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gg|gh|gi|gl|gm|gn|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|im|in|io|iq|ir|is|it|je|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|me|mg|mh|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|mv|mw|mx|my|mz|na|nc|ne|nf|ng|ni|nl|no|np|nr|nu|nz|om|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|ps|pt|pw|py|qa|re|ro|rs|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|Ja|sk|sl|sm|sn|so|sr|ss|st|su|sv|sx|sy|sz|tc|td|tf|tg|th|tj|tk|tl|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw)\b/?(?!@)))'
  
  re=$re_all
  if [ $# -gt 0 ] && [ "$1" = '-w' ]; then
      re=$re_web
  fi
  
  grep -oP "$re" "$@"

my favorite aliases

    # show the local Makefile targets
    alias targets="grep '^[^#[:space:]\.].*:' Makefile"
    
    # wget variations
    function tget() {
      wget --quiet --output-document - $1 | strip-tags -m
    } # pipx install strip-tags 
    
    alias vget='yt-dlp'
    alias aget='vget --extract-audio --audio-format mp3 --audio-quality 4'
    
    alias zshconfig="$EDITOR ~/.zshrc && reload"
    alias gitconfig="$EDITOR ~/.gitconfig"
    alias sshconfig="$EDITOR ~/.ssh/config"
    alias brewconfig="$EDITOR ~/Brewfile && brewup"
  
  alias brewup='brew bundle --file=~/Brewfile --quiet && brew update && brew upgrade'

    alias -g H=' | head'

    wget -qO example.com H

    wget -qO example.com | head

    alias -g H=' | head'
    alias -g T=' | tail'
    alias -g G=' | grep -i'
    alias -g C=' | pbcopy'
    alias -g XI=' | xargs -I _'

    #!/usr/bin/python3
    from datetime import date
    print(f"September {(date.today()-date(1993,9,1)).days+1}, 1993")

  #!/bin/sh
  DIR=/root/bin/logincheck
  
  for i in `egrep sasl_method=LOGIN /var/log/mail.log  |cut -d '[' -f 3 |cut -d   ']' -f 1 |sort |uniq`;
  do echo;
  
          echo
          if grep -qw "${i}" ${DIR}/history.txt; then
                  echo "         === ${i} === ";
          else
                  echo "         === ${i} (**NEW**) === ";
                  echo ${i} >> ${DIR}/history.txt
  
          fi
          whois $i |grep -i 'organ\|descr\|netname';
  done;