Keep incremental backups of edited files

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created March 9, 2005 · complexity basic · author Tim Doerfler · version 6.0

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I was wondering how I could make an automatic backup of my edited files. I added the following to my vimrc:

set backupdir=c:\temp\vim_backup
let myvar = strftime("(%y%m%d)[%Hh%M]")
let myvar = "set backupext=_". myvar
execute myvar

So the command which is executed in this example sounds like this:

set backupext=_(050309)[15h15]

This creates backups into c:\temp\vim_backup\ having names like myfile_(050309)[15h15] instead of myfile~

Each time my vim starts up for editing a file, backupext gets changed so I get at least one backup per day, without overwriting backups of the day before.

If I open and close that file more often, I could theoretically have one Backup each minute. ( But who would want to have that many backups ? )

Comments

With the following mapping:

fun! InitBex()
 let myvar = strftime("(%y%m%d)[%Hh%M]")
 let myvar = "set backupext=_". myvar
 execute myvar
 echo myvar
endfun
map <ESC> :call InitBex()<CR>

You can easily refresh the backupextension time everytime you hit the <ESC> key. So you can get backups every minute, every hour, every day and so on.

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If having multiple backups interests you, you may also consider script#89 savevers.vim by Ed Ralston or script#563 rcsvers.vim by Juan Frias and Roger Pilkey.

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If you guys need this kind of backup, invest in version control (I recommend subversion).

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You can determine how many backups you get by changing the backupext - String: If the backup - String contains minutes, you could get far too many backups ( maximum: one per minute ).

If you leave out the minutes, you get maximum one backup per hour. Leave out the hours -> one per day ...

We use version control for our standard - Software. But we do customizing, too for our customers. And all these customized functions differ from the standard. That's why I want a backup without using a CVS Tool

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If you are a sysadmin and trying to fix something, I think you *do* want that many backups. The drive space is cheap when compared with the cost of unnecesary downtime. I can always send the backups to my trash directory which is already managed. For that matter, I can probably set up logrotate to compress all of the text files in the users trash directories *and* delete the old ones.

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This seems to work for a backup each and every time the file has changed and it does so with a correctly dated and absolutely unique filename in the trash directory. mktemp gaurrenties uniqueness, if not my spelling. ;-) As for knowing when it was deleted, hey that's what we have file attributes for. A trash dumping utility would have to go by the file attributes anyway, right? So here we go:

set backup
" in .vimrc right after the text: "
"if has("autocmd") put this:"
augroup backups
 au!
"Note:Sorry, but this all goes on one line"
autocmd BufWritePost,FileWritePost * !diff -d <afile> <afile>~ &> /dev/null;if [[ $? == 1 ]];then touch <afile>~;mv <afile>~ `mktemp ~/Desktop/Trash/<afile>.XXXXXX`;fi
augroup END

"Note: If you see something like this, you know it is working:"

"leaves.txt" 182L, 2031C written
:!diff -d leaves.txt leaves.txt~ &> /dev/null;if [[ $? == 1 ]];then mv leaves.txt~ `mktemp ~/Desktop/Trash/leaves.txt.XXXXXX`;fi

OK, now let's discuss what it does:

#This line turns on backups:
set backup

#This line declares a new auto command group named backups.
augroup backups

#Erase any extra garbage commands that might be lying around.
 au!

autocmd BufWritePost,FileWritePost * !diff -d <afile> <afile>~ &> /dev/null;if [[ $? == 1 ]];then touch <afile>~;mv <afile>~ `mktemp ~/Desktop/Trash/<afile>.XXXXXX`;fi

# Of course, this is the end of our one-liner augroup statement.
augroup END

The above says create an new autocmd that will be executed when writing a file or buffer is finished. It will apply to files named "*". The bang (i.e. "!") identifies the command to be executed which comes next. The command itself is nothing more than a few BASH commands all on the same line. <afile> is the name of the affected file. Since we know that the name of the backup file is always "filename~", we can use <afile>~ to nail the backup file immediately after it has been written.

I could have just as easily used a bash script to take care of this. It would have been much neater to look at but not as copyable and self contained. The script would have looked like this:

#!/bin/bash
#This script is named trash.sh
diff -d $1 $2 &> /dev/null
if [[ $? == 1 ]]
 then touch <afile>~
 mv $2 `mktemp ~/Desktop/Trash/$1.XXXXXX`
fi

If I were to decide to put this script in my command path and use it, my autocmd line would have looked like this:

autocmd BufWritePost,FileWritePost * !trash.sh <afile> <afile>~

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I noticed that this doesn't work for vim (gvim) 6.4 and vim 7.0.

With help from others I got it tested and working for gvim 7.0. I assume for 6.4 it also work, but didn't test it.

The chars '[' and ']' are not working in strftime apparently, and therefore I used '{' and '}'

Copy this into your _vimrc:

fun! NewInitBex()
  let &bex = '-' . strftime("(%Y%m%d)-{%H%M}")
endfun

And instead of mapping the ESC char I used:

autocmd BufWritePre * call NewInitBex()

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Maybe it works if you escape the [ ] characters:

let &bex = '-' . strftime("(%Y%m%d)-\[%H%M\]")

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