Add `:SystemCopy` commandadd-command-mode

Enable System Copy to be executed from command mode.

    :SystemCopy

will copy the current line. A range can be specified to copy multiple
lines:

    :15,24SystemCopy

This lets users to copy lines without moving the cursor, and allows for
repeatability using the `@:` command.

2 files changed, 12 insertions, 1 deletions

diff --git a/README.md b/README.md
index e04c753..ce9ba1f 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,10 @@ In addition, `cP` is mapped to copy the current line directly.
 The sequence `cv` is mapped to paste the content of system clipboard to the
 next line.
 
+A command is also included that will copy the current line or a range of lines:
+
+`:15,24SystemCopy` => copy lines 15–24 into system clipboard
+
 Clipboard Utilities
 -------------------
 
diff --git a/plugin/system_copy.vim b/plugin/system_copy.vim
index d280e1e..89c5c26 100644
--- a/plugin/system_copy.vim
+++ b/plugin/system_copy.vim
@@ -7,6 +7,7 @@ let s:blockwise = 'blockwise visual'
 let s:visual = 'visual'
 let s:motion = 'motion'
 let s:linewise = 'linewise'
+let s:command_mode = 'command mode'
 let s:mac = 'mac'
 let s:windows = 'windows'
 let s:linux = 'linux'
@@ -16,6 +17,8 @@ function! s:system_copy(type, ...) abort
   if mode == s:linewise
     let lines = { 'start': line("'["), 'end': line("']") }
     silent exe lines.start . "," . lines.end . "y"
+  elseif mode == s:command_mode
+    silent exe a:1 . "," . a:2 . "y"
   elseif mode == s:visual || mode == s:blockwise
     silent exe "normal! `<" . a:type . "`>y"
   else
@@ -34,7 +37,9 @@ endfunction
 
 function! s:resolve_mode(type, arg)
   let visual_mode = a:arg != 0
-  if visual_mode
+  if a:type == s:command_mode
+    return s:command_mode
+  elseif visual_mode
     return (a:type == '') ?  s:blockwise : s:visual
   elseif a:type == 'line'
     return s:linewise
@@ -87,6 +92,8 @@ function! s:PasteCommandForCurrentOS()
   endif
 endfunction
 
+command! -range SystemCopy call <SID>system_copy(s:command_mode, <line1>, <line2>)
+
 xnoremap <silent> <Plug>SystemCopy :<C-U>call <SID>system_copy(visualmode(),visualmode() ==# 'V' ? 1 : 0)<CR>
 nnoremap <silent> <Plug>SystemCopy :<C-U>set opfunc=<SID>system_copy<CR>g@
 nnoremap <silent> <Plug>SystemCopyLine :<C-U>set opfunc=<SID>system_copy<Bar>exe 'norm! 'v:count1.'g@_'<CR>