lua-resty-shell - Lua module for nonblocking system shell command executions
local shell = require "resty.shell"
local stdin = "hello"
local timeout = 1000 -- ms
local max_size = 4096 -- byte
local ok, stdout, stderr, reason, status =
shell.run([[perl -e 'warn "he\n"; print <>']], stdin, timeout, max_size)
if not ok then
-- ...
end
syntax: ok, stdout, stderr, reason, status = shell.run(cmd, stdin?, timeout?, max_size?)
context: any phases supporting yielding
Runs a shell command, cmd
, with an optional stdin.
The cmd
argument can either be a single string value, like "echo 'hello, world'"
,
or an array-like Lua table, like {"echo", "hello, world"}
. The former form is
equivalent to {"/bin/sh", "-c", "echo 'hello, world'"}
, but just a little bit
faster.
When stdin is nil or an empty string, the stdin device will get closed immediately.
The timeout
parameter speifies the timeout threshold for stderr/stdout reading timeout,
the stdin writing timeout, and the process waiting timeout, respectively.
The max_size
parameter specifies the maximum size allowed for each output data stream of
stdout and stderr. When exceeding the limit, the run()
function will immediately
stop reading any more data from the stream and returns an error string in the reason
return
value like "failed to read stdout: too much data"
.
When the sub-process terminates by itself, the reason
return value will be "exit"
and the status
return value will be the exit code returned by the sub-process.
When the sub-process is terminated by some UNIX signals, the reason
return value
will be "signal"
and the status
return value will hold the signal number.
The first return value, ok
, will only take a true value (true
) when the process
is exited successfully (with the zero status code).
This library depends on
- the lua-resty-signal library.
- the ngx.pipe API of OpenResty.
- the lua-tablepool library.
Yichun Zhang (agentzh) [email protected]
This module is licensed under the BSD license.
Copyright (C) 2018-2019, OpenResty Inc.
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
-
Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
-
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
-
Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
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