Merge 5b410d1e49 into 0dd933265f

Problem: :read can read from files or stdin, but not from other Ex commands

Solution: use `put=execute(cmd)` to execute cmd and send its output to the
buffer

runtime/doc/insert.txt

@@ -2010,15 +2010,21 @@ NOTE: These commands cannot be used with |:global| or |:vglobal|.
 
 							*:r!* *:read!*
 :[range]r[ead] [++opt] !{cmd}
-			Execute {cmd} and insert its standard output below
-			the cursor or the specified line.  A temporary file is
-			used to store the output of the command which is then
-			read into the buffer.  'shellredir' is used to save
-			the output of the command, which can be set to include
-			stderr or not.  {cmd} is executed like with ":!{cmd}",
-			any '!' is replaced with the previous command |:!|.
+			Execute shell {cmd} and insert its standard output
+			below the cursor or the specified line.  A temporary
+			file is used to store the output of the command which
+			is then	read into the buffer.  'shellredir' is used to
+			save the output of the command, which can be set to
+			include stderr or not.  {cmd} is executed like with
+			":!{cmd}", any '!' is replaced with the previous
+			command |:!|.
 			See |++opt| for the possible values of [++opt].
 
+							*:r:* *:read:*
+:[range]r[ead] :{cmd}
+			Execute Ex command {cmd} and insert its output below
+			the cursor or the specified line.
+
 These commands insert the contents of a file, or the output of a command,
 into the buffer.  They can be undone.  They cannot be repeated with the "."
 command.  They work on a line basis, insertion starts below the line in which

runtime/doc/news.txt

@@ -217,6 +217,8 @@ EDITOR
   "~/" are now expanded to the user's profile directory, not a relative path
   to a literal "~" directory.
 • |hl-PmenuMatch| and |hl-PmenuMatchSel| show matched text in completion popup.
+• |:read:| reads the output of an Ex command into the buffer. Example:>
+    :read :ls
 
 EVENTS
 

src/nvim/ex_docmd.c

@@ -12,8 +12,10 @@
 #include <uv.h>
 
 #include "auto/config.h"
+#include "klib/kvec.h"
 #include "nvim/api/private/defs.h"
 #include "nvim/api/private/helpers.h"
+#include "nvim/api/vim.h"
 #include "nvim/arglist.h"
 #include "nvim/ascii_defs.h"
 #include "nvim/autocmd.h"
@@ -5826,6 +5828,31 @@ static void ex_syncbind(exarg_T *eap)
   }
 }
 
+void do_read_cmd(exarg_T *eap)
+{
+  Object cmd = CSTR_AS_OBJ(eap->arg + 1);
+  String cmd_var_name = cstr_as_string("_ex_cmd");
+  StringBuilder put_cmd = KV_INITIAL_VALUE;
+  Error error = ERROR_INIT;
+  nvim_set_var(cmd_var_name, cmd, &error);
+  if (error.type != kErrorTypeNone) {
+    emsg(error.msg);
+    return;
+  }
+
+  kv_printf(put_cmd, "%dput=execute(g:%s) | ", eap->line2, cmd_var_name.data);
+  kv_printf(put_cmd, "execute 'norm! )`.' | ");
+  kv_printf(put_cmd, "execute 'd _' | ");
+
+  do_cmdline(put_cmd.items, eap->ea_getline, eap->cookie, eap->flags);
+  kv_destroy(put_cmd);
+  nvim_del_var(cmd_var_name, &error);
+  if (error.type != kErrorTypeNone) {
+    emsg(error.msg);
+    return;
+  }
+}
+
 static void ex_read(exarg_T *eap)
 {
   int empty = (curbuf->b_ml.ml_flags & ML_EMPTY);
@@ -5835,6 +5862,11 @@ static void ex_read(exarg_T *eap)
     return;
   }
 
+  if (*eap->arg == ':') {
+    do_read_cmd(eap);
+    return;
+  }
+
   if (u_save(eap->line2, (linenr_T)(eap->line2 + 1)) == FAIL) {
     return;
   }

test/functional/ex_cmds/read_spec.lua

@@ -0,0 +1,94 @@
+local t = require('test.testutil')
+local n = require('test.functional.testnvim')()
+
+local eq, write_file, clear, pcall_err = t.eq, t.write_file, n.clear, t.pcall_err
+local fn = n.fn
+local setline, getline, setcharpos, execute = fn.setline, fn.getline, fn.setcharpos, fn.execute
+
+local tmp_file = 'text.txt'
+local original_text = { 'First', 'Last' }
+local read_text = { ' This is a line starts with a space', '  This one starts with two spaces.' }
+local inserted_middle = { original_text[1], read_text[1], read_text[2], original_text[2] }
+local inserted_start = { read_text[1], read_text[2], original_text[1], original_text[2] }
+
+local function test_read(cmd, expected)
+  setline(1, original_text)
+  setcharpos('.', { 0, 0, 0 })
+  execute(cmd)
+  for i, e in ipairs(expected) do
+    eq(e, getline(i))
+  end
+end
+
+local function test_undo(cmd)
+  setline(1, original_text)
+  execute(cmd)
+  execute('undo')
+  eq(original_text, { getline(1), getline(2) })
+end
+
+describe(':read', function()
+  local function cleanup()
+    os.remove(tmp_file)
+  end
+  before_each(function()
+    clear()
+    cleanup()
+    write_file(tmp_file, table.concat(read_text, '\n'), true)
+  end)
+  after_each(cleanup)
+  it('inserts text from file', function()
+    test_read('read ' .. tmp_file, inserted_middle)
+    eq({ 0, 2, 2, 0 }, fn.getpos('.'))
+  end)
+  it('inserts text from shell', function()
+    test_read('read !cat ' .. tmp_file, inserted_middle)
+    eq({ 0, 3, 3, 0 }, fn.getpos('.'))
+  end)
+  it('inserts text from Ex command', function()
+    local make_lines = string.format('let lines="%s"', table.concat(read_text, '\\n'))
+    execute(make_lines)
+    test_read('read :echo lines', inserted_middle)
+  end)
+  it('inserts text from file at specific position', function()
+    test_read('0read ' .. tmp_file, inserted_start)
+    eq({ 0, 1, 2, 0 }, fn.getpos('.'))
+  end)
+  it('inserts text from shell cmd at specific position', function()
+    test_read('0read !cat ' .. tmp_file, inserted_start)
+    eq({ 0, 2, 3, 0 }, fn.getpos('.'))
+  end)
+  it('executes next command when using |', function()
+    local make_lines = string.format('let lines="%s"', table.concat(read_text, '\\n'))
+    execute(make_lines)
+    execute("let guard = 'fail'")
+    test_read("read :echo lines | let guard='pass'", inserted_middle)
+    eq('pass', vim.trim(execute('echo guard')))
+  end)
+  it('sets fileformat, fileencoding, bomb correctly', function()
+    execute('set fileformat=dos')
+    execute('set fileencoding=latin1')
+    execute('set bomb')
+    execute('read ++edit ' .. tmp_file)
+    eq('fileformat=unix', vim.trim(execute('set fileformat?')))
+    eq('fileencoding=utf-8', vim.trim(execute('set fileencoding?')))
+    eq('nobomb', vim.trim(execute('set bomb?')))
+  end)
+  it('file reads can be undone', function()
+    test_undo('read ' .. tmp_file)
+  end)
+  it('shell reads can be undone', function()
+    test_undo('read !cat ' .. tmp_file)
+  end)
+  it('command reads can be undone', function()
+    local make_lines = string.format('let lines="%s"', table.concat(read_text, '\\n'))
+    execute(make_lines)
+    test_undo('read :echo lines')
+  end)
+  it('errors out correctly when a non-existant file is used', function()
+    eq("Vim(read):E484: Can't open file asdfasdf", pcall_err(execute, ':read asdfasdf'))
+  end)
+  it('errors out correctly when an invalid command is used', function()
+    eq('Vim:E492: Not an editor command: asdfasdf', pcall_err(execute, ':read :asdfasdf'))
+  end)
+end)