PROTOCOLS(5) File Formats Manual PROTOCOLS(5)

protocols — protocol name data base

The protocols file contains information regarding the known protocols used in the DARPA Internet. For each protocol a single line should be present with the following information:

official protocol name
protocol number
aliases

Items are separated by any number of blanks and/or tab characters. A ``#'' indicates the beginning of a comment; characters up to the end of the line are not interpreted by routines which search the file.

Protocol names may contain any printable character other than a field delimiter, newline, or comment character.

Processes generally find protocol records using one of the getprotoent(3) family of functions. On Mac OS X, these functions interact with the DirectoryService(8) daemon, which reads the /etc/protocols file as well as searching other directory information services to determine protocol name and number information.

/etc/protocols
 

getprotoent(3), DirectoryService(8)

The protocols file format appeared in 4.2BSD.

June 5, 1993 BSD 4.2