Named after the 8th-century B.C.E.^[4] Greek poet Hesiod, the hesiod system is a network information system developed as Project Athena. Information that is shared among many machines on a network can be accessed by each machine using a common set of library routines. Files that are commonly represented in this form are the passwd(4) and aliases(4) files used by sendmail. The hesiod system is patterned after the Internet DNS and uses BIND source.

^[4] This stands for Before Common Era. An alternative proposal that is making the rounds calls for signed years, thus the -8th century.

The HESIOD compile-time macro is used to enable use of the hesiod system. This macro is defined as zero (no hesiod) for all operating systems that are currently supported. To enable hesiod, add the following line to your Build m4 file:

APPENDDEF(`confMAPDEF', `-DHESIOD')

If HESIOD is defined when sendmail is built, support is included to look up aliases via the hesiod interface. Support is also included to declare and use hesiod class maps (Section 23.2.2) with the K configuration command. Support is also included to use hesiod with the User Database if USERDB is also defined.

Documentation and source are available from HESIOD:

ftp://athena-dist.mit.edu/pub/ATHENA/

If you are running a precompiled sendmail binary, you can use the -d0.1 debugging command-line switch (-d0.1) to determine if HESIOD support is included (if it appears in the list, support is included).