fix: 兼容无file命令/无grep -P的系统，下载加超时

ss-rust.sh

@@ -87,7 +87,7 @@ install_ssrust() {
     arch_name=$(get_arch)
 
     local latest
-    latest=$(curl -sLm10 https://api.github.com/repos/shadowsocks/shadowsocks-rust/releases/latest | grep tag_name | head -1 | grep -oP 'v[\d.]+')
+    latest=$(curl -sLm10 https://api.github.com/repos/shadowsocks/shadowsocks-rust/releases/latest | grep tag_name | head -1 | sed 's/.*"v/v/;s/".*//')
     [[ -z "$latest" ]] && latest="v1.24.0"
     info "版本: $latest"
 
@@ -95,13 +95,15 @@ install_ssrust() {
 
     cd /tmp
     rm -f ss-rust-dl.tar.xz ssserver sslocal ssurl ssmanager ssservice
-    curl -sL "$url" -o ss-rust-dl.tar.xz
+    curl -sLm120 "$url" -o ss-rust-dl.tar.xz
 
     local fsize
     fsize=$(stat -c%s ss-rust-dl.tar.xz 2>/dev/null || stat -f%z ss-rust-dl.tar.xz 2>/dev/null)
     [[ "$fsize" -lt 100000 ]] && error "下载失败 (${fsize} bytes)"
 
+    if command -v file &>/dev/null; then
         file ss-rust-dl.tar.xz | grep -q "XZ" || error "下载的文件不是有效的 XZ 压缩包"
+    fi
 
     tar xf ss-rust-dl.tar.xz || error "解压失败"
     [[ ! -f ssserver ]] && error "找不到 ssserver"