Add profile support to BackTunnel with defaults, named remotes, and seamless integration across CLI, GUI, and documentation

scripts/backtunnel-share

@@ -10,6 +10,75 @@
 
 set -euo pipefail
 
+# Config search order: user → system → packaged example
+CONFIG_USER="${XDG_CONFIG_HOME:-$HOME/.config}/backtunnel/profiles.ini"
+CONFIG_SYS="/etc/backtunnel/profiles.ini"
+CONFIG_PKG="/usr/share/backtunnel/profiles.ini"
+
+# resolve CONFIG_FILE to first existing
+if [[ -f "$CONFIG_USER" ]]; then
+  CONFIG_FILE="$CONFIG_USER"
+elif [[ -f "$CONFIG_SYS" ]]; then
+  CONFIG_FILE="$CONFIG_SYS"
+else
+  CONFIG_FILE="$CONFIG_PKG"
+fi
+
+# shellcheck disable=SC2317  # invoked later at runtime; ShellCheck can't see call path
+ini_get() { # ini_get SECTION KEY -> value
+  local sec="$1" key="$2"
+  awk -v s="[""$sec""]" -v k="$key" '
+    $0==s {ok=1; next}
+    /^\[/ {ok=0}
+    ok && $0 ~ /^[[:alnum:]_.-]+[[:space:]]*=/ {
+      line=$0
+      sub(/[[:space:]]*=[[:space:]]*/, "=", line)
+      split(line,a,"=")
+      if (a[1]==k) {
+        val=substr(line, index(line,"=")+1)
+        gsub(/^[[:space:]]+|[[:space:]]+$/,"",val)
+        print val
+        exit
+      }
+    }' "${CONFIG_FILE}" 2>/dev/null || true
+}
+
+# shellcheck disable=SC2317
+profile_expand_remote() { # "@name" -> user@host, otherwise pass through
+  local in="$1"
+  if [[ "$in" == @* ]]; then
+    local name="${in#@}" user host
+    user="$(ini_get "$name" user)"
+    host="$(ini_get "$name" host)"
+    if [[ -n "$user" && -n "$host" ]]; then
+      printf '%s@%s\n' "$user" "$host"
+      return 0
+    fi
+  fi
+  printf '%s\n' "$in"
+}
+
+# shellcheck disable=SC2317
+profile_apply_defaults() { # set globals if unset; named overrides default
+  local name="$1" v
+  # defaults
+  v="$(ini_get default tunnel_port)";    [[ -n "$v" && "${TUNNEL_PORT}" == "2222" ]] && TUNNEL_PORT="$v"
+  v="$(ini_get default local_ssh_port)"; [[ -n "$v" && "${LOCAL_SSH_PORT}" == "22"  ]] && LOCAL_SSH_PORT="$v"
+  v="$(ini_get default invite_mount)";   [[ -n "$v" && "${INVITE_MOUNT}" == "/mnt/remote-rssh" ]] && INVITE_MOUNT="$v"
+  v="$(ini_get default invite)";         [[ "${v,,}" == "true" ]] && INVITE=true
+  v="$(ini_get default qr)";             [[ "${v,,}" == "true" ]] && QR=true
+  if [[ -z "$DURATION" ]]; then
+    v="$(ini_get default duration)";     [[ -n "$v" ]] && DURATION="$v"
+  fi
+  # named section
+  if [[ -n "$name" ]]; then
+    v="$(ini_get "$name" tunnel_port)";    [[ -n "$v" ]] && TUNNEL_PORT="$v"
+    v="$(ini_get "$name" local_ssh_port)"; [[ -n "$v" ]] && LOCAL_SSH_PORT="$v"
+    v="$(ini_get "$name" invite_mount)";   [[ -n "$v" ]] && INVITE_MOUNT="$v"
+  fi
+}
+
+
 TUNNEL_PORT=2222       # remote-side port exposed via -R
 LOCAL_SSH_PORT=22      # local sshd port to forward to
 DURATION=""            # required: e.g. 30m, 2h, 1d
@@ -61,6 +130,15 @@ shift 5 || true
 [[ "$KW1" != "with" ]] && usage
 [[ "$KW2" != "for"  ]] && usage
 
+# Apply [default] + named profile (if REMOTE is @name) before flag overrides
+profile_name=""
+if [[ "$REMOTE" == @* ]]; then
+  profile_name="${REMOTE#@}"
+fi
+profile_apply_defaults "$profile_name"
+# Expand @name -> user@host for actual ssh use
+REMOTE="$(profile_expand_remote "$REMOTE")"
+
 # --- optional flags ---
 while [[ $# -gt 0 ]]; do
   case "$1" in