# &adminguide;

## Overview

This is a module which provides a FIFO transport layer implementation for Management Interface. It receives the command over a FIFO file and returns the output through the reply_fifo specified.

The module checks every 30 seconds if the FIFO file exists, and if it was deleted, it recreates it. If one wants to force the fifo file recreation, it should send a SIGHUP signal to the MI process PID.

## FIFO command syntax

The external commands issued via FIFO interface must follow the following syntax:

- request = first_line argument*

- first_line = ':'command_name':'reply_fifo'\n'

- argument = (arg_name '::' (arg_value)? ) | (arg_value)

- arg_name = not-quoted_string

- arg_value = not-quoted_string | '"' string '"'

- not-quoted_string = string - {',",\n,\r}

## Dependencies

### &osips; Modules

The following modules must be loaded before this module:

- No dependencies on other &osips; modules.

### External Libraries or Applications

The following libraries or applications must be installed before running &osips; with this module loaded:

- none

## Exported Parameters

### `fifo_name` (string)

The name of the FIFO file to be created for listening and reading external commands.

Default value is NONE.

#### Set `fifo_name` parameter

    ...
    modparam("mi_fifo", "fifo_name", "/tmp/opensips_fifo")
    ...

### `fifo_mode` (integer)

Permission to be used for creating the listening FIFO file. It follows the UNIX conventions.

Default value is 0660 (rw-rw----).

#### Set `fifo_mode` parameter

    ...
    modparam("mi_fifo", "fifo_mode", 0600)
    ...

### `fifo_group` (integer) `fifo_group` (string)

Group to be used for creating the listening FIFO file.

Default value is the inherited one.

#### Set `fifo_group` parameter

    ...
    modparam("mi_fifo", "fifo_group", 0)
    modparam("mi_fifo", "fifo_group", "root")
    ...

### `fifo_user` (integer) `fifo_group` (string)

User to be used for creating the listening FIFO file.

Default value is the inherited one.

#### Set `fifo_user` parameter

    ...
    modparam("mi_fifo", "fifo_user", 0)
    modparam("mi_fifo", "fifo_user", "root")
    ...

### `reply_dir` (string)

Directory to be used for creating the reply FIFO files.

Default value is /tmp/

#### Set `reply_dir` parameter

    ...
    modparam("mi_fifo", "reply_dir", "/home/opensips/tmp/")
    ...

### `reply_indent` (string)

Strings to be used for line indentation. As the MI data structure is tree oriendeted, the depth level will printed as indentation.

Default value is "\t" (TAB).

#### Set `reply_indent` parameter

    ...
    modparam("mi_fifo", "reply_indent", "    ")
    ...

## Exported Functions

No function exported to be used from configuration file.

## Example

This is an example showing the FIFO format for the get_statistics dialog: tm: MI commad: response.

### FIFO request

    :get_statistics:reply_fifo\n
    dialog:\n
    tm:\n
    \n