install.sh: add --only and --skip flags for subset installs

README.md

@@ -19,6 +19,16 @@ chmod +x install.sh
 
 Each `.ts` file in `extensions/` is symlinked into `~/.pi/agent/extensions/`. Existing real files are backed up with a timestamp. Re-runs are idempotent.
 
+**Install a subset:**
+
+```bash
+./install.sh --only ssh-controlmaster          # just this one
+./install.sh --only "ssh-controlmaster,other"  # explicit list
+./install.sh --skip "git-checkpoint"           # all except these
+```
+
+`--only` and `--skip` accept comma-separated names without the `.ts` suffix. `--only` takes precedence if both are given.
+
 ### Alternative: pi install (local path)
 
 Because `package.json` declares a `pi` manifest, you can also register this repo as a pi package:

install.sh

@@ -5,9 +5,12 @@
 # loads them automatically on every session. Idempotent and non-destructive.
 #
 # Usage:
-#   ./install.sh              # install (interactive confirm)
-#   ./install.sh --yes        # install without prompt
-#   ./install.sh --uninstall  # remove symlinks that point into this repo
+#   ./install.sh                          install all extensions
+#   ./install.sh --only ssh-controlmaster install one extension
+#   ./install.sh --only "ext1,ext2"       install a subset
+#   ./install.sh --skip "ext1,ext2"       install all except these
+#   ./install.sh --yes                    skip confirmation prompt
+#   ./install.sh --uninstall              remove symlinks that point into this repo
 
 set -euo pipefail
 
@@ -49,22 +52,34 @@ require_pi_installed() {
 # ── args ─────────────────────────────────────────────
 ACTION="install"
 ASSUME_YES="no"
+ONLY=""     # comma-separated names to include  (empty = all)
+SKIP=""     # comma-separated names to exclude  (empty = none)
 
 while [[ $# -gt 0 ]]; do
     case "$1" in
         --uninstall)  ACTION="uninstall"; shift ;;
         -y|--yes)     ASSUME_YES="yes"; shift ;;
+        --only)       ONLY="$2"; shift 2 ;;
+        --only=*)     ONLY="${1#--only=}"; shift ;;
+        --skip)       SKIP="$2"; shift 2 ;;
+        --skip=*)     SKIP="${1#--skip=}"; shift ;;
         -h|--help)
             cat <<EOF
 install.sh — install pi-extensions
 
 Usage:
-  ./install.sh              install (interactive confirm)
-  ./install.sh --yes        install without prompt
+  ./install.sh                          install all extensions
+  ./install.sh --only ssh-controlmaster install one extension
+  ./install.sh --only "ext1,ext2"       install a subset
+  ./install.sh --skip "ext1,ext2"       install all except these
+  ./install.sh --yes                    skip confirmation prompt
   ./install.sh --uninstall              remove symlinks that point into this repo
 
+--only and --skip accept comma-separated extension names (without .ts suffix).
+--only takes precedence over --skip if both are given.
+
 Each .ts file in extensions/ is symlinked into ~/.pi/agent/extensions/.
-Existing files that are already symlinked into this repo are left alone.
+Existing files already symlinked into this repo are left alone.
 Existing real files or foreign symlinks are backed up with a timestamp.
 EOF
             exit 0 ;;
@@ -72,6 +87,31 @@ EOF
     esac
 done
 
+# ── build install set ─────────────────────────────────
+# Populates INSTALL_SET associative array: keys are bare names (no .ts suffix).
+declare -A INSTALL_SET
+
+build_install_set() {
+    if [[ -n "$ONLY" ]]; then
+        # Explicit allowlist — only install what's named
+        IFS=',' read -ra names <<< "$ONLY"
+        for n in "${names[@]}"; do
+            INSTALL_SET["${n%.ts}"]=1
+        done
+    else
+        # Start with everything present on disk, then remove --skip entries
+        for f in "${EXTENSIONS_SRC}"/*.ts; do
+            [[ -e "$f" ]] && INSTALL_SET["$(basename "$f" .ts)"]=1
+        done
+        if [[ -n "$SKIP" ]]; then
+            IFS=',' read -ra names <<< "$SKIP"
+            for n in "${names[@]}"; do
+                unset "INSTALL_SET[${n%.ts}]" 2>/dev/null || true
+            done
+        fi
+    fi
+}
+
 # ── install ──────────────────────────────────────────
 do_install() {
     echo
@@ -80,24 +120,28 @@ do_install() {
     echo
 
     require_pi_installed
+    build_install_set
 
-    local extensions=("${EXTENSIONS_SRC}"/*.ts)
-    if [[ ! -e "${extensions[0]}" ]]; then
-        warn "No .ts files found in ${EXTENSIONS_SRC}/ — nothing to install."
+    if [[ ${#INSTALL_SET[@]} -eq 0 ]]; then
+        warn "No extensions selected — nothing to install."
         exit 0
     fi
 
     echo "==> Extensions to symlink into ${EXTENSIONS_DEST}/:"
-    for src in "${extensions[@]}"; do
-        printf '       %s\n' "$(basename "$src")"
+    for n in "${!INSTALL_SET[@]}"; do
+        printf '       %s.ts\n' "$n"
     done
     echo
     confirm || { echo "Aborted."; exit 0; }
     echo
 
-    for src in "${extensions[@]}"; do
+    for src in "${EXTENSIONS_SRC}"/*.ts; do
+        [[ -e "$src" ]] || continue
         local name
         name="$(basename "$src")"
+        local bare="${name%.ts}"
+        [[ -n "${INSTALL_SET[$bare]:-}" ]] || continue
+
         local dest="${EXTENSIONS_DEST}/${name}"
 
         note "Linking ${name}"