Naming and Directory Services (DNS, NIS, and LDAP)

TABLE 2–1 Switch File Information SourcesInformation SourcesfilesnisplusnisDescriptionA file stored in the client’s /etc directory. For example, /etc/passwdAn NIS+ table. For example, the hosts table.An NIS map. For example, the hosts map.compat compat can be used for password and group information to support old-style + or -syntax in /etc/passwd, /etc/shadow, and /etc/group files.dnsldapCan be used to specify that host information be obtained from DNS.Can be used to specify entries be obtained from the LDAP directory.Search CriteriaSingle Source. If an information type has only one source, such as nisplus a routineusing the switch searches for the information in that source only. If the routine findsthe information, the routine returns a success status message. If the routine does notfind the information, the routine stops searching and returns a different statusmessage. What the routine does with the status message varies from routine toroutine.Multiple Sources. If a table contains multiple sources for a given information type, theswitch directs the routine to search in the first listed source. If the routine finds theinformation, the routine returns a success status message. If the routine does notfind the information in the first source, the routine tries the next source. The routinesearches all sources until the routine has found the information, or until the routine ishalted by a return specification. If all of the listed sources are searched withoutfinding the information, the routine stops searching and returns a non-successstatus message.Switch Status MessagesIf a routine finds the information, the routine returns a success status message. If theroutine does not find the information, the routine returns one of three error statusmessages. Possible status messages are listed in the following table.TABLE 2–2 Switch Search Status MessagesStatus MessageSUCCESSMeaning of MessageThe requested entry was found in the specified source.Chapter 2 • The Name Service Switch (Overview) 33