Add first version of git-cp

bin/git-cp

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+PROGRAM=$0
+CURRENT_FILENAME=""
+DESTINATION_FILENAME=""
+
+function current_branch() {
+    git rev-parse --abbrev-ref HEAD
+}
+
+function usage()
+{
+    echo "USAGE: ${PROGRAM} CURRENT_FILENAME DESTINATION_FILENAME"
+}
+
+while [[ $# > 0 ]]
+do
+  key="$1"
+  
+  if [[ "$CURRENT_FILENAME" == "" ]]; then
+      CURRENT_FILENAME=$key
+  elif [[ "$DESTINATION_FILENAME" == "" ]]; then
+      DESTINATION_FILENAME=$key
+  else
+      usage
+      exit 30  # Error during arguments parsing
+  fi
+  shift  # past argument or value
+done
+
+if [[ "$DESTINATION_FILENAME" == "" ]]; then
+    usage
+    exit 20  # Missing arguments CURRENT_FILENAME
+elif [[ "$CURRENT_FILENAME" == "" ]]; then
+    usage
+    exit 10  # Missing arguments CURRENT_FILENAME
+else
+    echo "Coping $CURRENT_FILENAME into $DESTINATION_FILENAME"
+    INTERMEDIATE_FILENAME="${CURRENT_FILENAME//\//__}-move-to-${DESTINATION_FILENAME//\//__}"
+
+    # We keep the existing file on the side in a commit
+    git mv "${CURRENT_FILENAME}" "${INTERMEDIATE_FILENAME}"
+    git commit -nm "Keep $CURRENT_FILENAME"
+    SAVED=$(git rev-parse HEAD)
+
+    # We come back to the previous state
+    git reset --hard HEAD^  # Revert that change
+
+    # We move the file to its new destination
+    git mv "${CURRENT_FILENAME}" "${DESTINATION_FILENAME}"
+    git add "${DESTINATION_FILENAME}"
+    git commit -nm "Copy $CURRENT_FILENAME into $DESTINATION_FILENAME"
+
+    # We get back our copy
+    rm -f "${DESTINATION_FILENAME}"  # Make sure the file doesn't exists somehow
+    git merge ${SAVED}
+    git commit -a -m "Duplicate ${CURRENT_FILENAME} history."  # Keeping both files
+
+    # We get back our original name
+    git mv "${INTERMEDIATE_FILENAME}" "${CURRENT_FILENAME}"
+    git commit -nm "Set back $CURRENT_FILENAME file."
+fi