Bardzo Podstawowy System Kontroli Wersji.

Wymagania:
  * bash
  * tee
  * diff
  * gzip
  * md5sum

  #!/usr/bin/bash
  # very basic version control system
  
  # let's check current directory
  PWD=$(pwd)
  
  # check flags and do stuff
  if [ "$1" = "init" ] ; then
    # initialize repository
    mkdir $PWD/stable
    mkdir $PWD/test
    mkdir $PWD/archive
    touch $PWD/zzzrepo
    echo "$(date): repository initialized" | tee -a $PWD/zzzrepo
  
  # compare stable, test and archives  
  elif [ "$1" = "diff" ] ; then
    if [ -z $2 ] ; then
      # diff test and stable directories
      diff -d -r $PWD/test/ $PWD/stable/
    else
      # diff test and stable directories with the content of specified archive
      mkdir $PWD/archive/difftemp
      tar -zxvf $PWD/$2 -C $PWD/archive/difftemp
      echo "------ Test ------"
      diff -d -r $PWD/test $PWD/archive/difftemp/test
      echo " "
      echo " ----- Stable ------"
      diff -d -r $PWD/stable $PWD/archive/difftemp/stable
      rm -fr $PWD/archive/difftemp
      echo " "
    fi
  
  # copy test to stable
  elif [ "$1" = "merge" ] ; then
    # overwrite stable with test
    rm -fr $PWD/stable/*
    cp --recursive $PWD/test/* $PWD/stable/
    echo "$(date): merged test into stable" | tee -a $PWD/zzzrepo
  
  # save stable and test as archive
  elif [ "$1" = "save" ] ; then
    # save test and stable as an archive under a name of date and time
    # also make md5 hashes
    timestamp=$(date +%F_%T)
    echo "Making md5 hashes of files in test..."
    find $PWD/test -type f -print0 | xargs -0 md5sum > $PWD/test/zzztest.md5
    echo "Making md5 hashes of files in stable..."
    find $PWD/stable -type f -print0 | xargs -0 md5sum > $PWD/stable/zzzstable.md5
    tar -zcf $PWD/archive/$timestamp.tar.gz test/ stable/
    echo "$(date): repository archived" | tee -a $PWD/zzzrepo
  
  # restore stable and / or test from archive  
  elif [ "$1" = "load" ] ; then
    if [ -z $3 ] ; then
      # overwrite test and stable with content of the specified archive
      rm -fr $PWD/test
      rm -fr $PWD/stable
      tar -zxf $2 -C $PWD
      echo "$(date): restored backup from $2 archive" | tee -a $PWD/zzzrepo
    elif [ "$3" = "test" ] ; then
      # overwite just test with content of specified archive
      rm -fr $PWD/test 
      tar -k -zxf $2 -C $PWD &> /dev/null
      echo "$(date): restored test repo backup from $2 archive" | tee -a $PWD/zzzrepo
    elif [ "$3" = "stable" ] ; then
      # overwrite just stable with content of specified archive
      rm -fr $PWD/stable
      tar -k -zxf $2 -C $PWD &> /dev/null
      echo "$(date): restored stable repo backup from $2 archive" | tee -a $PWD/zzzrepo
    fi
  
  # create md5 sums of files from stabkle and test
  if [ "$1" = "md5" ] ; then
    # create md5 of each file in test and stable
    find $PWD/test/ -type f -print0 | xargs -0 md5sum > $PWD/test/zzztest.md5
    find $PWD/stable/ -f type -f -print0 | xargs -0 md5dum > $PWD/stable/zzzstable.md5
    echo "$(date): sums written into test/zzztest.md5 and stable/zzzstable.md5 files." | tee -a $PWD/zzzrepo
  fi
  
  # help 
  elif [ -z $1 ] ; then
    # echo some instructions
    echo " "
    echo -e "Please specify:\r
     zzzver init - to create new repository,\r
     zzzver diff - to compare test and stable repo,\r
     zzzver diff archive/name.tar.gz - to compare test and stable with specified archive,\r
     zzzver merge - to copy test into stable,\r
     zzzver save - to archive test and stable as date_time.tar.gz,\r
     zzzver load archive/name.tar.gz - to replace test and stable with content of specified archive,\r
     zzzver load archive/name.tar.gz test - to replace test with content of specified archive,\r
     zzzver load archive/name.tar.gz stable - to replace stable with content of specified archive.\r
     zzzver md5 - to make md5 hashes of files from testing and stable."
     echo " "
  
  # catch wrong parameters
  else
    echo "I give up, you wrote something wrong. :("
    echo "Run zzzver without parameters to get some help."
    echo " "
  fi