timestamps

If true, prefixes stderr timestamps

nanoseconds

If non-empty, timestamp displays nanoseconds.

app_log_hook

name of function that implements app_log_pipe

error_usage_hook

name of function that implements error_usage

app_log

Calls app_log_hook

script_log_pipe_stub

This definition is a temporary handler for debugging

library loading. When the script library is loaded, it is replaced

by the final version located therein.

error_usage

print an error and current command usage

error_usage_stub

This stub prints an unadorned error; the 'commands'

library provides a version to print the usage information.