update document of build

README.md

@@ -21,8 +21,75 @@ clang-format -style="{BasedOnStyle: webkit}" -i  XX.c
 
 使用默认 gofmt
 
-# 3. misc
+# 3. build environment and build (example of ubuntu)
-## 3.1. Windows remap ctrl and alt key
+## 3.1 build environment
+ 
+- Install nix package management tool
+
+```sh
+sh <(curl -L https://nixos.org/nix/install) --daemon
+```
+
+- Edit /etc/nix/nix.conf to make sure
+
+```
+experimental-features = nix-command flakes
+sandbox = true
+sandbox-fallback = false
+substituters = https://mirrors.ustc.edu.cn/nix-channels/store https://cache.nixos.org https://cache.nixos.org/
+trusted-users = root <your account>
+```
+
+make sure that you have restarted nix-daemon service after you have checked /etc/nix/nix.conf
+
+- Install socat  and config ssh (for clone by ssh protocol) 
+
+```sh
+nix profile add nixpkgs#socat
+```
+
+.ssh/config
+```
+Host gitea.shenrs.eu
+	HostName gitea.shenrs.eu
+	IdentityFile ~/.ssh/id_ed25519
+	ProxyCommand socat - openssl-connect:gitea.shenrs.eu:2022,snihost=gitea.shenrs.eu,verify=0
+```
+
+## 3.2 checkout source code
+
+## 3.3 build (for package and release)
+
+```sh
+cd xce/src
+
+# for build debug version
+nix build --option sandbox false .#xce_debug
+
+# for normal build
+nix build --option sandbox false .#xce
+```
+
+You can find the generated binaries at =result= directory
+
+## 3.4 build (for daily develop)
+
+```sh
+cd xce/src
+nix develop
+
+# using meson to generated build configuration (debug and address sanitize)
+
+meson setup build --buildtype=debug -Db_sanitize=address
+
+# run meson to build
+meson compile -C  build
+
+# The generated files will be in build/
+```
+
+# 4. misc
+## 4.1. Windows remap ctrl and alt key
 create a reg file, e.g. remapkey.reg
 ```
 Windows Registry Editor Version 5.00