Utility Functions

Some useful utility functions.

Check arguments

Checks arguments from the mympd_arguments global variable.

local tocheck = {
    uri = "notempty",
    entries = "number",
    view = "required"
}
local rc, msg = mympd.check_arguments(tocheck)
if rc == false then
    return msg
end

Parameters:

PARAMETER	TYPE	DESCRIPTION
tocheck	table	Lua table of arguments to check.

The tocheck parameter expects a lua table consisting of arguments to check as key and one of notempty, number or required as value.

• notempty: Checks for a not empty string.
• number: Checks if the argument can be converted to a Lua number.
• required: Checks if the argument is there.

Hashing functions

local md5_hash = mympd.hash_md5(string)
local sha1_hash = mympd.hash_sha1(string)
local sha256_hash = mympd.hash_sha256(string)

Parameters:

PARAMETER	TYPE	DESCRIPTION
string	string	String to hash

HTML encoding

local encoded = mympd.htmlencode(string)

Parameters:

PARAMETER	TYPE	DESCRIPTION
string	string	String to encode

URL encoding and decoding

local encoded = mympd.urlencode(string)
local decoded = mympd.urldecode(string, form_url_decode)

Parameters:

PARAMETER	TYPE	DESCRIPTION
string	string	String to encode/decode
form_url_decode	boolean	Decode as form url

Logging

Logs messages to the myMPD log. You can use the number or the loglevel name.

mympd.log(loglevel, message)

-- This is the same
mympd.log(5, message)
mympd.log("LOG_NOTICE", message)

Parameters:

PARAMETER	TYPE	DESCRIPTION
message	string	Message to log
loglevel	number or string	Syslog log level

LOGLEVEL	NUMBER	DESCRIPTION
LOG_EMERG	0	Emergency
LOG_ALERT	1	Alert
LOG_CRIT	2	Critical
LOG_ERR	3	Error
LOG_WARNING	4	Warning
LOG_NOTICE	5	Notice
LOG_INFO	6	Informational
LOG_DEBUG	7	Debug

Return message from script

local msg = "test"

-- Debug
return mympd.jsonrpc_notification(7, msg)

-- Info
return msg

-- Notice
return mympd.jsonrpc_notification(5, msg)

-- Warning
return mympd.jsonrpc_warn(msg)

-- Error
return mympd.jsonrpc_error(msg)

-- Critical
return mympd.jsonrpc_notification(2, msg)

-- Alert
return mympd.jsonrpc_notification(1, msg)

-- Emergency
return mympd.jsonrpc_notification(0, msg)

Notifications

-- Send a notification to the client that has started the script
mympd.notify_client(severity, message)

-- Send a notification to all clients in the partition from which the client started the script
mympd.notify_partition(severity, message)

Parameters:

PARAMETER	TYPE	DESCRIPTION
severity	number or string	Severity
message	string	Message to send.

SEVERITY	NUMBER	DESCRIPTION
SEVERITY_EMERG	0	Emergency
SEVERITY_ALERT	1	Alert
SEVERITY_CRIT	2	Critical
SEVERITY_ERR	3	Error
SEVERITY_WARNING	4	Warning
SEVERITY_NOTICE	5	Notice
SEVERITY_INFO	6	Informational
SEVERITY_DEBUG	7	Debug

Read an ascii file

local content = mympd.read_file(path)

Parameters:

PARAMETER	TYPE	DESCRIPTION
path	string	Filepath to open and read.

Remove a file

Deletes a file or empty directory. It is a wrapper for os.remove that logs the error on failure.

local rc, errorstr = mympd.remove_file(path)

Parameters:

PARAMETER	TYPE	DESCRIPTION
path	string	Filepath to delete.

Sleep

mympd.sleep(ms)

Parameters:

PARAMETER	TYPE	DESCRIPTION
ms	positive number	Milliseconds