Jiri
Kuthan
FhG FOKUS

    		    jiri@iptel.org

2003
FhG FOKUS
$Revision: 1.3 $
$Date: 2005/08/24 22:26:18 $

# Exec Module

## Overview

Exec module allows to start an external command from a ser script. The commands may be any valid shell commands, the command string is passed to shell using "popen" command. ser passes additionally lot of information about request in environment variables:

- SIP_HF_<hf_name> contains value of each header field in request. If a header field occurred multiple times, values are concatenated and comma-separated. <hf_name> is in capital letters. Ff a header-field name occurred in compact form, <hf_name> is canonical.

- SIP_TID is transaction identifier. All request retransmissions or CANCELs/ACKs associated with a previous INVITE result in the same value.

- SIP_DID is dialog identifier, which is the same as to-tag. Initially, it is empty.

- SIP_SRCIP is source IP address from which request came.

- SIP_ORURI is original Request-URI.

- SIP_RURI is current Request-URI (if unchanged, equal to original).

- SIP_USER is userpart of current Request-URI.

- SIP_OUSER is userpart of original Request-URI.

## Known Issues

There is currently no guarantee that scripts ever return and stop blocking SIP server. (There is `kill.c` but it is not used along with the current mechanisms based on popen. Besides that `kill.c` is ugly).