Rename bootstrap directory

Renamed bootstrap directory to _bootstrap to conform to default ignore
pattern of autostow.sh, and make it visually clear that this is a
special directory, not one used for the dotfiles itself.

_bootstrap/autostow.sh

@@ -0,0 +1,129 @@
+#!/usr/bin/env bash
+#
+# autostow.sh
+#
+# Stow automatic symlinking script
+#
+# Invokes stow for every folder within this repository, and that's it.
+
+ignore="${AUTOSTOW_IGNORED_DIRS}"
+
+main() {
+  case "$1" in
+  -s | --stow)
+    have_stow
+    stow_dirs
+    exit 0
+    ;;
+  -d | --delete)
+    have_stow
+    unstow_dirs
+    exit 0
+    ;;
+  -n | --dry-run)
+    have_stow
+    dryrun
+    exit 0
+    ;;
+  -v | --version)
+    printf "System bootstrap script.\n\n©Marty Oehme\n\nVersion: 0.2.1\n"
+    ;;
+  -h | --help | *)
+    usage
+    exit 0
+    ;;
+  esac
+  shift
+}
+
+stow_dirs() {
+  printf "Creating dotfile symlinks .................................................\n"
+  for d in */; do
+
+    if is_ignored "$d"; then
+      printf "ignoring %s\n" "$d"
+      continue
+    fi
+
+    printf "stowing %s\n" "$d"
+    stow -S -t ~ "$d"
+  done
+  printf "Done creating symlinks ....................................................\n"
+}
+
+unstow_dirs() {
+  printf "Removing dotfile symlinks .................................................\n"
+  for d in */; do
+
+    if is_ignored "$d"; then
+      printf "ignoring %s\n" "$d"
+      continue
+    fi
+
+    printf "unstowing %s\n" "$d"
+    stow -D -t ~ "$d"
+  done
+  printf "Done removing symlinks ....................................................\n"
+}
+
+dryrun() {
+  printf "Printing processed directories ............................................\n"
+  for d in */; do
+
+    if is_ignored "$d"; then
+      printf "ignoring %s\n" "$d"
+      continue
+    fi
+
+    printf "processing %s\n" "$d"
+  done
+  printf "Done printing directories .................................................\n"
+}
+
+is_ignored() {
+  IFS=":"
+  for ign in $ignore; do
+    # it is either passed in through our environment variable
+    if [ "$ign" = "$1" ] || [ "$ign/" = "$1" ]; then
+      return 0
+    fi
+  done
+  # or it starts with a _ which is ignored by default (that's the regex).
+  # (using herestring to avoid cat>grep)
+  if grep -q -e '^_[[:alnum:]]\{1,\}' <<<"$1"; then return 0; fi
+  return 1
+}
+
+have_stow() {
+  if ! type stow >/dev/null 2>&1; then
+    printf "GNU stow needs to be installed for this script to function. Please install stow through your package manager.\n"
+    exit 1
+  fi
+}
+
+usage() {
+  printf "%s\n" \
+    "" \
+    " autostow.sh - Automatically stow your dotfiles." \
+    "               Uses GNU stow to set up automatic links to any dotfiles in subdirectories of this directory." \
+    "" \
+    " Usage: stow.sh -dhsn" \
+    "" \
+    " Options:" \
+    "" \
+    "     -h | --help     Print out this help." \
+    "" \
+    "     -s | --stow     Install dotfiles, by symlinking any directory found next to stow.sh using GNU stow." \
+    "" \
+    "     -d | --delete   Remove dotfiles, by unlinking any directory found next to stow.sh using GNU stow." \
+    "" \
+    "     -n | --dry-run  Do not invoke any operation but print out directories affected, simulating a dry-run." \
+    "" \
+    " Note, by default any directory starting with an underscore _directoryname will be ignored." \
+    " Additional folders to ignore can be set through the environment variable AUTOSTOW_IGNORED_DIRS " \
+    " using a colon-separated string: AUTOSTOW_IGNORED_DIRS=\"directories:to:ignore\"   " \
+    "" \
+    ""
+}
+
+main "$@"