This page shows how to extract one version back from svn on given file.

1. The scripts gets a file name. It uses the command svn log to extract one version back, and overwrites the file with this version.
   On a tcsh, I use the following command to run the script on a list of files:
   
   
   1. cat ~/my_txt/my_svn_log.txt | xargs -n1 | xargs -t -i= ~/bin/svn_one_ver_back.unx =
      


2. The script is shown below:
   
   
   1. #!/bin/bash
      
   2. 
      
   3. #\.\/\([a-zA-Z].*\) r[0-9]* .*
      
   4. svn_ver=`svn log $1 | grep "^r[0-9]* " | head -2 | tail -1 | perl -e 'while (<STDIN>) {$t=index($_, " ");$s=substr($_, 0, $t);print("$s\n");};'`
      
   5. svn cat -r $svn_ver $1 > $1
      


3. Note, that bash script calls perl in one line command invocation.



4. Now suppose you want to change reveisions listed in a given file. This file contains the target files and their new revisions. In my case the file was created by the following script.
   The output of this script looks like:
   
   
   1. Tue Nov 6 09:39:52 IST 2012
      
   2. ./main_data/Clib/init.c r2 | dkuku | 2012-06-25 16:21:34 +0300 (Mon, 25 Jun 2012) | 1 line
      
   3. ./main_data/Clib/dbg_cmd.c r2 | dkuku | 2012-06-25 16:21:34 +0300 (Mon, 25 Jun 2012) | 1 line
      
   4. ...
      
   
   
   My idea is to take each line from the file, extract its name and version and update. This can be achieved by the following script:
   
   1. #!/bin/bash
      
   2. 
      
   3. #restores to tag
      
   4. #~/bin/svn_tag.unx ~/restricted/my_svn_log_24779.txt
      
   5. OIFS="$IFS" #see below on IFS
      
   6. IFS=$'\n'
      
   7. 
      
   8. for li in `cat $1 | grep " r[0-9]* "`; do
      
   9.   svn_ver=`echo $li | perl -e 'while (<STDIN>) {$t=index($_, " r");$s=substr($_, $t);$t=index($s, " |");$s=substr($s, 0, $t);print("$s\n");};'`
      
   10.   f=`echo $li | perl -e 'while (<STDIN>) {$t=index($_, " r");$s=substr($_, 0, $t);print("$s\n");};'`
       
   11.   
       
   12.   echo "file: "$svn_ver" version: "$f
       
   13.   svn cat -r $svn_ver $f > $f
       
   14. done
       
   15. 
       
   16. IFS="$OIFS"
       
   
   Note that the bash scripts calls perl to extract some fields.

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