More elegant way to create a smarter "extract" function in my .bashrc

graysky · 2010-12-24 09:48:12

I picked up the "extract" function somewhere and added it to my ~/.bashrc. I want to make it inspect the first dir that it extracts and cd into it upon a successful extraction so I came up with the following:

extract () {
   if [ -f $1 ] ; then
       case $1 in
           *.tar.bz2)   tar xvjf $1 && cd $(echo $1 | sed 's/.tar.bz2//')    ;;
           *.tar.gz)    tar xvzf $1 && cd $(echo $1 | sed 's/.tar.gz//')    ;;
           *.bz2)       bunzip2 $1 && cd $(echo $1 | sed 's/.bz2//')    ;;
           *.rar)       unrar x $1 && cd $(echo $1 | sed 's/.rar//')    ;;
           *.gz)        gunzip $1 && cd $(echo $1 | sed 's/.gz//')    ;;
           *.tar)       tar xvf $1 && cd $(echo $1 | sed 's/.tar//')    ;;
           *.tbz2)      tar xvjf $1 && cd $(echo $1 | sed 's/.tbz2//')    ;;
           *.tgz)       tar xvzf $1 && cd $(echo $1 | sed 's/.tgz//')    ;;
           *.zip)       unzip $1 && cd $(echo $1 | sed 's/.zip//')    ;;
           *.Z)         uncompress $1 && cd $(echo $1 | sed 's/.Z//')    ;;
           *.7z)        7z x $1 && cd $(echo $1 | sed 's/.7z//')    ;;
           *)           echo "don't know how to extract '$1'..." ;;
       esac
   else
       echo "'$1' is not a valid file!"
   fi
 }

Two questions:

1) Is there a more elegant way to code this behavior?
2) I'd like to add the behavior of "[ if -d $i]; then cd $i else exit" where $i is just the filename without the extension that my sed statement makes but again, without adding one line per extension, is there a more elegant way to code this?

Last edited by graysky (2010-12-24 09:49:19)

dyscoria · 2010-12-24 11:32:37

I'm no expert, but you could do something like:

 *.tar.bz2)   tar xvjf $1 && [[ -d ${1%.tar.bz2} ]] && cd ${1%.tar.bz2}    ;;

Awebb · 2010-12-24 11:51:50

By more elegant you mean... written in one line and harder to modify? :-D

AugustePop · 2010-12-24 15:42:18

i think the more elegant way is putting the cd and related commands after the case switch, or write a wrapper function.

SiD · 2010-12-24 15:44:58

have a look at unp

juster · 2010-12-24 15:47:32

I would consider using basename a little easier and/or more elegant:

case $1 in
    *.tar.bz2)   tar xvjf $1 && cd $(basename "$1" .tar.bz2) ;;

Last edited by juster (2010-12-24 15:49:47)

falconindy · 2010-12-24 16:05:56

there's no guarantee that the directory extracted is related to the name of the tarball. or that there's a directory at all.

wonder · 2010-12-24 16:23:47

why scripting such thing when you can use only tar xf tarball?

Bralkein · 2010-12-30 20:55:55

Hey I was bored and so I had a stab at this one. Dunno if this is an elegant solution exactly (it seems a bit fiddly) but it seems to do what you asked for without repetition of code.

extract () {
    if [ ! -f "$1" ] ; then
      echo "'$1' is not a valid file!"
      return 1
    fi

    # Assoc. array of commands for extracting archives
    declare -A xcmd
    xcmd=(
      [.tar.bz2]="tar xvjf"
      [.tar.gz]="tar xvzf"
      [.bz2]="bunzip2"
      [.rar]="unrar x"
      [.gz]="gunzip"
      [.tar]="tar xvf"
      [.zip]="unzip"
      [.Z]="uncompress"
      [.7z]="7z x"
    )
    # extension aliases
    xcmd[.tbz2]="${xcmd[.tar.bz2]}"
    xcmd[.tgz]="${xcmd[.tar.gz]}"

    # See which extension the given file uses
    fext=""
    for i in ${!xcmd[@]}; do
      if [ $(grep -o ".\{${#i}\}$" <<< $1) == "$i" ]; then
        fext="$i"
        break
      fi
    done

    # Die if we couldn't discover what archive type it is
    if [ -z "$fext" ]; then
      echo "don't know how to extract '$1'..."
      return 1
    fi

    # Extract & cd if we can
    fbase=$(basename "$1" "$fext")
    if ${xcmd[$fext]} "$1" && [ -d "$fbase" ]; then
      cd "$fbase"
    fi
}

I don't do all that much bash scripting so handle with caution!

Edit: Changed the code - quoted a bunch of stuff so it doesn't break on files with spaces in the name. Told you I don't do much of this!
Edit 2: Nicer way of initialising the assoc array

Last edited by Bralkein (2010-12-31 02:00:33)

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#1 2010-12-24 09:48:12

More elegant way to create a smarter "extract" function in my .bashrc

#2 2010-12-24 11:32:37

Re: More elegant way to create a smarter "extract" function in my .bashrc

#3 2010-12-24 11:51:50

Re: More elegant way to create a smarter "extract" function in my .bashrc

#4 2010-12-24 15:42:18

Re: More elegant way to create a smarter "extract" function in my .bashrc

#5 2010-12-24 15:44:58

Re: More elegant way to create a smarter "extract" function in my .bashrc

#6 2010-12-24 15:47:32

Re: More elegant way to create a smarter "extract" function in my .bashrc

#7 2010-12-24 16:05:56

Re: More elegant way to create a smarter "extract" function in my .bashrc

#8 2010-12-24 16:23:47

Re: More elegant way to create a smarter "extract" function in my .bashrc

#9 2010-12-30 20:55:55

Re: More elegant way to create a smarter "extract" function in my .bashrc

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