# HG changeset patch
# User jbe
# Date 1497216437 -7200
# Node ID 7d53e12f0804bb8d5675cc41bde427e10256524c
# Parent  9b7a391fd46112e5b7baeca145e3ce6fafd64b41
New function execute.command{...}

diff -r 9b7a391fd461 -r 7d53e12f0804 framework/env/execute/command.lua
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/framework/env/execute/command.lua	Sun Jun 11 23:27:17 2017 +0200
@@ -0,0 +1,136 @@
+--[[--
+output,           -- collected data from stdout if process exited successfully
+errmsg =          -- error message if execution failed or if process didn't exit successfully
+execute.command{
+  command               = { filename, arg1, arg2, ... },  -- command and arguments
+  stdin_data            = stdin_data,                     -- optional data to be sent to process via stdin
+  stdout_result_handler = stdout_result_handler,          -- callback receiving: stdout data, success boolean, optional error message
+  stderr_line_handler   = stderr_line_handler,            -- callback for processing stderr line-wise
+  exit_handler          = exit_handler,                   -- callback when process exited
+  signal_handler        = signal_handler,                 -- callback when process terminated due to signal
+  timeout_handler       = timeout_handler,                -- callback when process gets killed due to timeout
+  abort_handler         = abort_handler,                  -- callback when process gets killed due to request by poll function
+  abortable             = abortable,                      -- set to true if process shall be terminated if poll function requests termination
+  poll                  = poll,                           -- alternative poll command with moonbridge_io.poll(...) semantics
+  db                    = db,                             -- database handle for waiting for notifies
+  db_notify_handler     = db_notify_handler               -- handler for database notifications which may return true to kill process
+}
+
+--]]--
+
+function execute.command(args)
+
+  local moonbridge_io = require("moonbridge_io")
+  local poll = args.poll or moonbridge_io.poll
+
+  local start = moonbridge_io.timeref()
+  local process, errmsg = moonbridge_io.exec(table.unpack(args.command))
+  if not process then return nil, errmsg end
+
+  local stdout_chunks, stderr_chunks = {}, {}
+  local read_fds = {[process.stdout] = true, [process.stderr] = true}
+  local write_fds = {[process.stdin] = true}
+  if args.db then
+    read_fds[args.db.fd] = true
+  end
+
+  local function return_error(errmsg)
+    if args.stdout_result_handler then
+      args.stdout_result_handler(table.concat(stdout_chunks), false, errmsg)
+    end
+    return nil, errmsg
+  end
+
+  local function write(...)
+    if write_fds[process.stdin] then
+      local buffered = process.stdin:flush_nb(...)
+      if not buffered or buffered == 0 then
+        process.stdin:close()
+        write_fds[process.stdin] = nil
+      end
+    end
+  end
+  write(args.stdin_data or "")
+
+  while
+    read_fds[process.stdout] or read_fds[process.stderr] or
+    write_fds[process.stdin]
+  do
+    local timeout = args.timeout and args.timeout-moonbridge_io.timeref(start)
+    local pollstatus, pollmsg, pollterm =
+      poll(read_fds, write_fds, timeout, args.abortable)
+    if not pollstatus then
+      process:kill():wait()
+      if pollterm then
+        if args.abort_handler then args.abort_handler() end
+      else
+        if args.timeout_handler then args.timeout_handler() end
+      end
+      return return_error(pollmsg)
+    end
+    if args.db then
+      local channel, payload, pid = db:wait(0)
+      if channel then
+        if args.db_notify_handler(channel, payload, pid) then
+          process:kill():wait()
+          return return_error("Database event received")
+        end
+      end
+    end
+    if read_fds[process.stdout] then
+      local chunk, status = process.stdout:read_nb()
+      if not chunk or status == "eof" then
+        process.stdout:close()
+        read_fds[process.stdout] = nil
+      end
+      if chunk and chunk ~= "" then
+        stdout_chunks[#stdout_chunks+1] = chunk
+      end
+    end
+    if read_fds[process.stderr] then
+      local chunk, status = process.stderr:read_nb()
+      if not chunk or status == "eof" then
+        process.stderr:close()
+        read_fds[process.stderr] = nil
+      end
+      if chunk and args.stderr_line_handler then
+        while true do
+          local chunk1, chunk2 = string.match(chunk, "(.-)\n(.*)")
+          if not chunk1 then break end
+          stderr_chunks[#stderr_chunks+1] = chunk1
+          args.stderr_line_handler(table.concat(stderr_chunks))
+          stderr_chunks = {}
+          chunk = chunk2
+        end
+        if chunk ~= "" then
+          stderr_chunks[#stderr_chunks+1] = chunk
+        end
+        if status == "eof" then
+          local line = table.concat(stderr_chunks)
+          if #line > 0 then args.stderr_line_handler(line) end
+        end
+      end
+    end
+    write()
+  end
+
+  local status = process:wait()
+
+  if status < 0 then
+    if args.signal_handler then
+      args.signal_handler(-status)
+    end
+    return return_error("Command terminated by signal " .. -status)
+  elseif status > 0 then
+    if args.exit_handler then
+      args.exit_handler(status)
+    end
+    return return_error("Command returned exit code " .. status)
+  elseif args.stdout_result_handler then
+    args.stdout_result_handler(table.concat(stdout_chunks), true)
+    return true
+  else
+    return table.concat(stdout_chunks)
+  end
+
+end