Michiel comment on Bash One-Liners Explained, Part I: Working with files

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Michiel Permalink

June 01, 2012, 22:54

Hi Peteris,

great reading as always. I wondered if you had a solution for a different user preference in #10: I personally prefer to have the extension intact when renaming the file to its name.

I.e. cp /path/to/file.ext /path/to/file_bk.ext

Probably not something I want to do by hand every time, but would be great as a small bash script e.g. 'bk' to first create a safe backup of a file I want to mess with and then automatically launch vim to edit the original.

Thanks!

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Comment Responses

Rafael Rendon Pablo Permalink

June 02, 2012, 17:57

What do you think about this?:

cp /long/path/to/file{,_bk}.ext

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Peteris Krumins pkrumins Permalink

June 02, 2012, 20:32

Here is a function called bk that does it. It works with files both of form file.ext and also files of form file (without ext). It also checks if the destination file doesn't exist. If it does, it adds _bk until such file doesn't exist. After it's copied the file it opens the original in vim.

function bk {
 if [[ -z $1 ]]; then
    echo "Usage: bk <file>"
    return
 fi

 file=$(basename $1)
 bk=_bk

 while :; do
  case $file in
   *.*)
    newfile=$(echo $file | sed 's/\(.*\)\.\(.*\)/\1'$bk'.\2/')
    ;;
   *)
    newfile=${file}$bk
    ;;
  esac
  if [[ ! -e $newfile ]]; then
   break
  fi
  bk=${bk}_bk
 done

 cp "$1" "$(dirname $1)/$newfile"
 if [[ $? -eq 0 ]]; then
    vim "$1"
 fi
}