What is your single most favorite command-line trick using Bash? [closed]

Answer 1

Renaming/moving files with suffixes quickly:
cp /home/foo/realllylongname.cpp{,-old}

This expands to:
cp /home/foo/realllylongname.cpp /home/foo/realllylongname.cpp-old

Answer 2

My favorite command is "ls -thor"

It summons the power of the gods to list the most recently modified files in a conveniently readable format.

Answer 3

pbcopy

This copies to the Mac system clipboard. You can pipe commands to it...try:

pwd | pbcopy

Answer 4

One preferred way of navigating when I'm using multiple directories in widely separate places in a tree hierarchy is to use acf_func.sh (listed below). Once defined, you can do

cd --

to see a list of recent directories, with a numerical menu

cd -2

to go to the second-most recent directory.

Very easy to use, very handy.

Here's the code:

# do ". acd_func.sh"
# acd_func 1.0.5, 10-nov-2004
# petar marinov, http:/geocities.com/h2428, this is public domain

cd_func ()
{
  local x2 the_new_dir adir index
  local -i cnt

  if [[ $1 ==  "--" ]]; then
    dirs -v
    return 0
  fi

  the_new_dir=$1
  [[ -z $1 ]] && the_new_dir=$HOME

  if [[ ${the_new_dir:0:1} == '-' ]]; then
    #
    # Extract dir N from dirs
    index=${the_new_dir:1}
    [[ -z $index ]] && index=1
    adir=$(dirs +$index)
    [[ -z $adir ]] && return 1
    the_new_dir=$adir
  fi

  #
  # '~' has to be substituted by ${HOME}
  [[ ${the_new_dir:0:1} == '~' ]] && the_new_dir="${HOME}${the_new_dir:1}"

  #
  # Now change to the new dir and add to the top of the stack
  pushd "${the_new_dir}" > /dev/null
  [[ $? -ne 0 ]] && return 1
  the_new_dir=$(pwd)

  #
  # Trim down everything beyond 11th entry
  popd -n +11 2>/dev/null 1>/dev/null

  #
  # Remove any other occurence of this dir, skipping the top of the stack
  for ((cnt=1; cnt <= 10; cnt++)); do
    x2=$(dirs +${cnt} 2>/dev/null)
    [[ $? -ne 0 ]] && return 0
    [[ ${x2:0:1} == '~' ]] && x2="${HOME}${x2:1}"
    if [[ "${x2}" == "${the_new_dir}" ]]; then
      popd -n +$cnt 2>/dev/null 1>/dev/null
      cnt=cnt-1
    fi
  done

  return 0
}

alias cd=cd_func

if [[ $BASH_VERSION > "2.05a" ]]; then
  # ctrl+w shows the menu
  bind -x "\"\C-w\":cd_func -- ;"
fi

Answer 5

Expand complicated lines before hitting the dreaded enter

• Alt+Ctrl+e — shell-expand-line (may need to use Esc, Ctrl+e on your keyboard)
• Ctrl+_ — undo
• Ctrl+x, * — glob-expand-word

$ echo !$ !-2^ * Alt+Ctrl+e
$ echo aword someotherword * Ctrl+_
$ echo !$ !-2^ * Ctrl+x, *
$ echo !$ !-2^ LOG Makefile bar.c foo.h

&c.

Answer 6

cd -

It's the command-line equivalent of the back button (takes you to the previous directory you were in).