add edit script

user/bin/edit

@@ -0,0 +1,45 @@
+#!/bin/sh
+if [ "$#" -ne 1 ]; then
+  echo "usage: $0 <file>"
+  exit 1
+fi
+
+first_link () {
+  if [ "${1%/*}" != "$1" ]; then
+    local x="$(first_link "${1%/*}")"
+  fi
+  if [ -z "$x" ] && [ -L "$1" ]; then
+    echo "$1"
+  else
+    echo "$x"
+  fi
+}
+
+NIX="$HOME/.local/nixos/user"
+FIRST="$(first_link "$(realpath -s "$1")")"
+if ! [ -z "$FIRST" ]; then
+  LINKED="$(realpath "$FIRST")"
+  if [ "${LINKED#/nix/store/}" != "$LINKED" ]; then
+    CONFIG="${FIRST#~/.config/}"
+    if [ "$CONFIG" != "$FIRST" ] && [ -e "$NIX/config/$CONFIG" ]; then
+      rm "$FIRST"
+      ln -s "$NIX/config/$CONFIG" "$FIRST"
+      $EDITOR "$1"
+      exit
+    fi
+    BIN="${FIRST#~/.local/bin}"
+    if [ "$BIN" != "$FIRST" ] && [ -e "$NIX/bin/$BIN" ]; then
+      rm "$FIRST"
+      ln -s "$NIX/bin/$BIN" "$FIRST"
+      $EDITOR "$1"
+      exit
+    fi
+    echo "not symlinkable"
+    exit 1
+  fi
+fi
+if ! [ -e "$1" ]; then
+  DIR="${1%/*}"
+  [ "$DIR" != "$1" ] && mkdir -p "$DIR"
+fi
+$EDITOR "$1"