5.10. Flat Files and Their Directory Services Counterparts

As mentioned earlier, Directory Services manages information for several flat files in earlier releases of Mac OS X, including /etc/printcap, /etc/mail/aliases, /etc/protocols, and /etc/services. For a complete list of known flat file formats, see the nidump and niload manpages.

Although you can edit these flat files directly as you would on any other Unix system, you can also use Directory Services to manage this information. You can use niload with a supported flat file format to add entries, or you can use dscl or NetInfo Manager to directly manipulate the entries. Table 5-2 lists each flat file, the corresponding portion of the directory, and important properties associated with each entry. See the netinfo(5) manpage for complete details. Properties marked with (list) can take multiple values using the dscl merge command (for an example, see "Adding Users to a Group," earlier in this chapter.)

The "Flat files or local database?" column in Table 5-2 indicates whether Directory Services consults the flat file, the local database, or both. You can use Directory Access to modify the way information is looked up on your Macintosh.

Table 5-2. Flat files and their NetInfo counterparts

Flat file	NetInfo directory	Important properties	Flat files or local database?
/etc/exports	/exports	name, clients (list), opts (list)	Flat files
/etc/fstab	/mounts	name, dir, type, opts (list), passno, freq	Local database
/etc/group	/groups	name, passwd, gid, users (list)	Local database
/etc/hosts	/machines	ip_address, name (list)	Both; entries in /etc/hosts take precedence
/etc/mail/aliases	/aliases	name, members (list)	Flat files
/etc/networks	/networks	name (list), address	Flat files
/etc/passwd, /etc/ master.passwd	/users	name, passwd, uid, gid, realname, home, shell	Local database
/etc/printcap	/printers	name, and various printcap properties (see the printcap(5) manpage)	Flat files
/etc/protocols	/protocols	name (list), number	Flat files
/etc/rpc	/rpcs	name (list), number	Flat files
/etc/services	/services	name (list), port, protocol (list)	Flat files