system_open: use asynchronous vim.loop to spawn process + let user customize the command to be used to open a file/folder with default system application (#551)

README.md

@@ -145,7 +145,7 @@ highlight NvimTreeFolderIcon guibg=blue
 - type `]c` to go to next git item
 - type `[c` to go to prev git item
 - type `-` to navigate up to the parent directory of the current file/directory
-- type `s` to open a file with default system application or a folder with default file manager
+- type `s` to open a file with default system application or a folder with default file manager (if you want to change the command used to do it see `:h g:nvim_tree_system_open_command` and `:h g:nvim_tree_system_open_command_args`)
 - if the file is a directory, `<CR>` will open the directory otherwise it will open the file in the buffer near the tree
 - if the file is a symlink, `<CR>` will follow the symlink (if the target is a file)
 - `<C-v>` will open the file in a vertical split

doc/nvim-tree-lua.txt

@@ -198,6 +198,20 @@ Can be `0` or `1`. When `1`, will close the tree when a file is opened.
 Applies to: `edit`, `vsplit`, `split`, `tabnew`.
 Default is 0
 
+|g:nvim_tree_system_open_command|      *g:nvim_tree_system_open_command*
+
+A string containing the command used to open a file/folder with default system
+application. If left unset it will be automatically filled with the right
+command, depending on the operating system. If your operating system isn't
+recognized or if you want to use another command you can edit it.
+Default: depends on the operating system
+
+|g:nvim_tree_system_open_command_args| *g:nvim_tree_system_open_command_args*
+
+An array of strings containing the arguments to be passed to the command
+specified in |g:nvim_tree_system_open_command|.
+Default: unset if not using Windows
+
 |g:nvim_tree_disable_keybindings|          *g:nvim_tree_disable_keybindings*
 
 Can be `0` or `1`. When `1`, will disable all keybindings by the plugin.

lua/nvim-tree.lua

@@ -97,34 +97,47 @@ local keypress_funcs = {
     return lib.open_file('preview', node.absolute_path)
   end,
   system_open = function(node)
-    local system_command
-    if vim.fn.has('win16') == 1 or vim.fn.has('win32') == 1 or vim.fn.has('win64') == 1 then
-      system_command = 'start "" '
-    elseif vim.fn.has('win32unix') == 1 then
-      if vim.fn.stridx(vim.fn.system('uname'), 'CYGWIN') ~= -1 then
-        system_command = 'cygstart '
+    if vim.g.nvim_tree_system_open_command == nil then
+      if vim.fn.has('win32') == 1 or vim.fn.has('win32unix') == 1 then
+        vim.g.nvim_tree_system_open_command = 'cmd'
+        vim.g.nvim_tree_system_open_command_args = {'/c', 'start', '""'}
+      elseif vim.fn.has('mac') == 1 or vim.fn.has('macunix') == 1 then
+        vim.g.nvim_tree_system_open_command = 'open'
+      elseif vim.fn.has('unix') == 1 then
+        vim.g.nvim_tree_system_open_command = 'xdg-open'
       else
-        system_command = 'start "" '
+        error('\nNvimTree system_open: cannot open file with system application. Unrecognized platform.\nPlease fill g:nvim_tree_system_open_command with the name of the system file launcher.')
+        return
       end
-    elseif vim.fn.has('mac') == 1 or vim.fn.has('macunix') == 1 then
-      system_command = 'open '
-    elseif vim.fn.has('unix') == 1 then
-      system_command = 'xdg-open '
-    else
-      vim.cmd('echohl ErrorMsg')
-      vim.cmd('echomsg "NvimTree system_open: cannot open file with system application. Unsupported platform."')
-      vim.cmd('echohl None')
+    end
+
+    local process = {}
+    process.args = vim.g.nvim_tree_system_open_command_args or {}
+    table.insert(process.args, node.link_to or node.absolute_path)
+    process.errors = '\n'
+    process.stderr = luv.new_pipe(false)
+    process.handle, process.pid = luv.spawn(vim.g.nvim_tree_system_open_command,
+      {args = process.args, stdio = {nil, nil, process.stderr}},
+      function(code)
+        process.stderr:read_stop()
+        process.stderr:close()
+        process.handle:close()
+        if code ~= 0 then
+          process.errors = process.errors .. string.format('NvimTree system_open: return code %d.', code)
+          error(process.errors)
+        end
+      end
+    )
+    if not process.handle then
+      error("\n" .. process.pid .. "\nNvimTree system_open: failed to spawn process using '" .. vim.g.nvim_tree_system_open_command .. "'.")
       return
     end
-
-    local command_output = vim.fn.system(system_command .. '"' .. vim.fn.substitute(node.absolute_path, '"', '\\\\"', 'g') .. '"')
-
-    if vim.v.shell_error ~= 0 then
-      vim.cmd('echohl ErrorMsg')
-      vim.cmd(string.format('echomsg "NvimTree system_open: return code %d."', vim.v.shell_error))
-      vim.cmd('echomsg "' .. vim.fn.substitute(command_output, '\n', '" | echomsg "', 'g') .. '"')
-      vim.cmd('echohl None')
-    end
+    luv.read_start(process.stderr,
+      function(err, data)
+        if err then return end
+        if data then process.errors = process.errors .. data end
+      end
+    )
   end,
 }