Add modules

modules/lib-bash/activation-init.sh

@@ -0,0 +1,20 @@
+if [[ -v VERBOSE ]]; then
+    export VERBOSE_ECHO=echo
+    export VERBOSE_ARG="--verbose"
+else
+    export VERBOSE_ECHO=true
+    export VERBOSE_ARG=""
+fi
+
+if [[ -v DRY_RUN ]] ; then
+    echo "This is a dry run"
+    export DRY_RUN_CMD=echo
+else
+    $VERBOSE_ECHO "This is a live run"
+    export DRY_RUN_CMD=""
+fi
+
+if [[ -v VERBOSE ]]; then
+    echo -n "Using Nix version: "
+    nix --version
+fi

modules/lib-bash/color-echo.sh

@@ -0,0 +1,37 @@
+# The check for terminal output and color support is heavily inspired
+# by https://unix.stackexchange.com/a/10065.
+
+function setupColors() {
+    normalColor=""
+    errorColor=""
+    warnColor=""
+    noteColor=""
+
+    # Check if stdout is a terminal.
+    if [[ -t 1 ]]; then
+        # See if it supports colors.
+        local ncolors
+        ncolors=$(tput colors)
+
+        if [[ -n "$ncolors" && "$ncolors" -ge 8 ]]; then
+            normalColor="$(tput sgr0)"
+            errorColor="$(tput bold)$(tput setaf 1)"
+            warnColor="$(tput setaf 3)"
+            noteColor="$(tput bold)$(tput setaf 6)"
+        fi
+    fi
+}
+
+setupColors
+
+function errorEcho() {
+    echo "${errorColor}$*${normalColor}"
+}
+
+function warnEcho() {
+    echo "${warnColor}$*${normalColor}"
+}
+
+function noteEcho() {
+    echo "${noteColor}$*${normalColor}"
+}