SVN -- recursive diffs

It's odd that svn (source control) doesn't have an easy way to see the entire evolution of a file. Since I'm usually wondering how and when something was changed, or just want to see the progression of the changes.

So I just wrote a quick shell script to do this:

#!/bin/bash

# 2008 GPL

if [[ $1 == "" ]]
then

  echo "SVN RECURSIVE DIFF"
  echo ""
  echo "This script will list all svn changes to a file"
  echo "the first and last file in the repository"
  echo "and a series of diffs that connect them."
  echo "IE, you can see the complete evolution of the file."
  echo "It's probably best to pipe the output to a file."
  echo ""
  echo "USE"
  echo "  svnrdiff "
  echo ""
  echo "EXAMPLE"
  echo "  svnrdiff Model/ModelExample.cs > somefile.txt"
  echo ""
  echo "NOTES"
  echo ""
  echo "If your log is out of date, use"
  echo ""
  echo "  svn up"
  echo ""
  echo "If you just want to see who last touched a line, use"
  echo ""
  echo "  svn praise "
  exit 

fi

v1=""
v2=""
show_current="0"

while read log
do

  echo ===================================================================
  echo $log
  echo ===================================================================

  # grab revision numbers of file
  v1=$( echo $log | sed -e 's/^r//' -e 's/ .*//' -e 's/-//g' ) 

  if [[ $v2 != ""  ]]
  then 

    # print succesive diffs
    svn diff -r $v2:$v1 $1

    show_current="1"

  else 

    # print first file
    svn cat -r $v1 $1

  fi

  v2=$v1

# list in cronological order (tac)
done < <( svn log $1 | grep -E -e "^r[0-9]+ \| " | tac )

# print last file (if haven't already)
echo ===================================================================
echo "Current snapshot:"
echo ===================================================================
if [[ $show_current == "1" ]]
then
  svn cat $1
else
  echo "Same as above."
fi