Definition of an arbitrary number of external programs/scripts (see Chapter 7 ). Section heading:
[External]
Entries:
      OpenCommand=
      
      /full/path/to/program — Starts
      new command definition.
CloseCommand — Ends new command definition (optional syntactic sugar).
      SetType=
      log/srv —
      Type/purpose of the program.
      SetCommandline=
      list — The command
      line.
      SetEnviron=
      KEY=value —
      Environment variable (can be repeated).
      SetChecksum=
      TIGER checksum —
      Checksum of the program.
      SetCredentials=
      username — User
      whose credentials shall be used.
      SetFilterNot=
      list — Regular
      expression patterns not allowed in message.
      SetFilterAnd=
      list — Regular
      expression patterns required (ALL) in message.
      SetFilterOr=
      list — Regular
      expression patterns required (at least one) in
      message.
      SetDeadtime=
      seconds — Deadtime
      between consecutive calls.
      SetDefault=
      boolean — Set
      default environment (HOME from /etc/passwd, SHELL=/bin/sh,
      PATH=/sbin:/usr/sbin:/bin:/usr/bin).