8.4 Defining Custom Accounting Types

If the built-in accounting methods do not meet your requirements, you can implement your own. There are two ways of doing so:

1. Using a Guile procedure.
2. Using an external program

To use a Guile procedure for accounting, the name of the procedure must be specified as a value to the Scheme-Acct-Procedure attribute in the RHS list of a `hints' entry, e.g.:

DEFAULT NULL Scheme-Acct-Procedure = "my-acct"

For a detailed description of Scheme accounting procedures, see section 11.3.3 Accounting with Scheme.

Another way of implementing your own accounting method is using an external program. This is less effective than the methods described above, but may be necessary sometimes. To invoke the program, use the following statement in the LHS of the `hints' entry:

Acct-Ext-Program = "progname args"

The progname must be the full path to the program, and args any arguments it needs. The usual substitutions may be used in args to pass any request attributes to the program (see section 5.14 Macro Substitution).

For a detailed description of Acct-Ext-Program, see section 14.3.1 Acct-Ext-Program.