sendmail, 4th Edition

-d38.20

Trace database map lookups Debug command-line switch

The -d38.20 debugging switch traces many different map lookups. The getcanonname( ) routine looks up a hostname and tries to canonify it:

getcanonname(host), trying dbtype
getcanonname(host), found
getcanonname(host), failed, stat=error

Here, host is the hostname that is being looked up, and dbtype is one of files, nis, nisplus, dns, or netinfo. If the canonical name is not found, the error shows one of the errors listed in <sysexits.h>. The process of canonifying the name is handled by calling special subroutines based on the dbtype:

text_getcanonname(host)                 ← dbtype is files
nis_getcanonname(host)                  ← dbtype is nis
nisplus_getcanonname(host), qbuf=query     ← dbtype is nisplus
dns_getcanonname(host, flag)              ← dbtype is dns, printed with -d8.2
ni_getcanonname(host)                   ← dbtype is netinfo

The nisplus_getcanonname( ) routine is far more verbose than the other. In addition to the preceding information, the -d38.20 switch also prints:

nisplus_getcanonname(host), got count entries, all but first ignored
nisplus_getcanonname(host), found in directory "nisdir"
nisplus_getcanonname(host), found result
nisplus_getcanonname(host), failed, status=nsistatus, nsw_stat=errno

The -d38.20 debugging switch also traces general lookups in various kinds of databases. Again note that nisplus is more verbose than the others:

ndbm_map_lookup(name, key)
db_map_lookup(name, key)
nis_map_lookup(name, key)
nisplus_map_lookup(name, key)
qbuf=query nisplus_map_lookup( ...