###########################################################
## DECLARATIONS IN SCITE PROPERTIES
###########################################################
# define lua scripts
ext.lua.startup.script=$(SciteUserHome)/.SciTEUser.lua

# define entry in context menu
user.context.menu=||Insert Snippet|1121|\

# define the command '21'
command.name.21.*=Insert Snippet
command.21.*=InsertSnip
command.save.before.21.*=2
command.subsystem.21.*=3
command.replace.selection.21.*=0

###########################################################
## DECLARATIONS IN $(SciteUserHome)/.SciTEUser.lua
###########################################################
function capture(cmd)
  local f = assert(io.popen(cmd, 'r'))
  local s = assert(f:read('*a'))
  f:close()
  return s
end

function InsertSnip()
   editor:AddText(capture('gsnip'))
end

Scite : insert command output in the editor

Textpattern