extractor for the most usual archive formats

extract-all.sh

#!/bin/bash
# all-in-one extractor for the most usual archive formats. Requires Bash >= 4 
set -e -u -o pipefail

declare -A COMMANDS=(
  [z]="compress -d"
  [gz]="gunzip"
  [bz2]="bunzip2"
  [zip]="unzip -qo"
  [rar]="unrar x"
  [tar]="tar xf"
  [tgz]="tar xzf"
  [7z]="7z x"
)

if test $# -eq 0; then
  echo -e "Usage: extract FILE [FILE2 ...]\n"
  echo "Supported extensions: ${!COMMANDS[@]}"
  exit 2
fi
   
for FILE in "$@"; do
  EXTENSION=$(echo "$FILE" | awk -F . '{print $NF}' | tr '[A-Z]' '[a-z]')
  COMMAND=${COMMANDS[$EXTENSION]:-}
  if test "$COMMAND"; then 
    $COMMAND "$FILE"
  else
    echo "[$FILE] unknown extension: $EXTENSION" >&2
  fi
done

If I am correct, 7z is now 7za.

Apparently 7z handles more formats: http://www.linuxquestions.org/questions/linux-software-2/what-is-difference-between-usr-bin-7za-usr-bin-7z-473474/