Add script for checking out git repositories

scripts/xx_checkout_repo.sh

@@ -0,0 +1,74 @@
+#!/bin/bash
+#
+# This scripts checks out spack from the repo
+# Input arguments:
+#   - repo:          url to repo in git format
+#   - release_tag:   tag/branch/commit in repo
+#   - release_dir:
+#   - destination:   checkout into directory <release_dir>/<destination>  
+# 
+
+_VERBOSITY=1
+
+if [[ "$#" -ne 4 ]]; then
+  echo "Syntax: $0 repo release_tag release_dir destination"
+  echo "Checkout tag <release_tag> from repo <repo> into path <release_dir>/<destination>."
+fi 
+
+arg_repo=$1
+arg_tag=$2
+arg_dir=$3
+arg_destination=$4
+
+log () {
+    local msg=$1
+    if [[ -n $_VERBOSITY ]]; then 
+        echo $msg
+    fi
+}
+
+# check repository name for plausibility
+check_repo () {
+    echo $1
+}
+
+# modify tag if necessary
+canonize_tag () {
+    echo $1
+}
+
+# create and prepare destination directory
+create_dir () {
+    local dir=$1
+    local rc
+
+    if [[ -d $dir ]]; then
+        rc=""
+    else
+        mkdir -p $dir
+        chmod g=u $dir
+        rc=$dir
+    fi
+    echo $rc
+}
+
+checkout_git () {
+    local repo=$1
+    local tag=$2
+    local dir=$3
+
+    pushd $dir
+    git clone --depth=1 --single-branch --branch=$tag -c feature.manyFiles=true $repo .
+    popd
+
+}
+
+repo=$(check_repo $arg_repo)
+release_tag=$(canonize_tag $arg_tag)
+destination_dir=$(create_dir $arg_dir/$arg_destination)
+if [[ -z $destination_dir ]]; then
+    log "Covardly refusing to overwrite existing directory $arg_dir/$arg_destination."
+else
+    log "Checking out Spack from $repo at tag $release_tag into directory $destination_dir"
+    checkout_git $repo $release_tag $destination_dir
+fi