Add dryrun capability to autostow.sh

Invoking a dry-run with `autostow.sh -n` will simply print out the
directories it would operate on, and those it would ignore and exit.
Useful for debugging, not much more.

bootstrap/autostow.sh

@@ -24,6 +24,13 @@ main() {
     echo "Done removing symlinks ...................................................."
     exit 0
     ;;
+  -n | --dry-run)
+    have_stow
+    echo "Printing processed directories ............................................"
+    dryrun
+    echo "Done printing directories ................................................."
+    exit 0
+    ;;
   -v | --version)
     printf "System bootstrap script.\n\n©Marty Oehme\n\nVersion: 0.2\n"
     ;;
@@ -61,6 +68,18 @@ unstow_dirs() {
   done
 }
 
+dryrun() {
+  for d in */; do
+
+    if is_ignored "$d"; then
+      printf "ignoring %s\n" "$d"
+      continue
+    fi
+
+    printf "processing %s\n" "$d"
+  done
+}
+
 is_ignored() {
   IFS=":"
   for ign in $ignore; do
@@ -84,13 +103,17 @@ usage() {
     " autostow.sh - Automatically stow your dotfiles." \
     "               Uses GNU stow to set up automatic links to any dotfiles in subdirectories of this directory." \
     "" \
-    " Usage: stow.sh -dhs" \
+    " Usage: stow.sh -dhsn" \
     "" \
     " Options:" \
     "" \
-    "     -h     Print out this help." \
+    "     -h | --help     Print out this help." \
     "" \
-    "     -s     Install dotfiles, by symlinking any directory found next to stow.sh using GNU stow." \
+    "     -s | --stow     Install dotfiles, by symlinking any directory found next to stow.sh using GNU stow." \
+    "" \
+    "     -d | --delete   Remove dotfiles, by unlinking any directory found next to stow.sh using GNU stow." \
+    "" \
+    "     -n | --dry-run  Do not invoke any operation but print out directories affected, simulating a dry-run." \
     "" \
     "     -d     Remove dotfiles, by unlinking any directory found next to stow.sh using GNU stow." \
     "" \