GETPROTOENT

Section: C Library Functions (3)
Index Return to Main Contents

BSD mandoc
BSD 4.2

NAME

getprotoent getprotobynumber getprotobyname setprotoent endprotoent - get protocol entry

SYNOPSIS

Fd #include <netdb.h> Ft struct protoent * Fn getprotoent Ft struct protoent * Fn getprotobyname char *name Ft struct protoent * Fn getprotobynumber int proto Fn setprotoent int stayopen Fn endprotoent

DESCRIPTION

The Fn getprotoent , Fn getprotobyname , and Fn getprotobynumber functions each return a pointer to an object with the following structure containing the broken-out fields of a line in the network protocol data base, /etc/protocols

struct  protoent {
        char    *p_name;        /* official name of protocol */
        char    **p_aliases;    /* alias list */
        int     p_proto;        /* protocol number */
};

The members of this structure are:

Fa p_name: The official name of the protocol.
Fa p_aliases: A zero terminated list of alternate names for the protocol.
Fa p_proto: The protocol number.

The Fn getprotoent function reads the next line of the file, opening the file if necessary.

The Fn setprotoent function opens and rewinds the file. If the Fa stayopen flag is non-zero, the net data base will not be closed after each call to Fn getprotobyname or Fn getprotobynumber .

The Fn endprotoent function closes the file.

The Fn getprotobyname function and Fn getprotobynumber sequentially search from the beginning of the file until a matching protocol name or protocol number is found, or until EOF is encountered.

RETURN VALUES

Null pointer (0) returned on EOF or error.

FILES

/etc/protocols

HISTORY

The Fn getprotoent , Fn getprotobynumber , Fn getprotobyname , Fn setprotoent , and Fn endprotoent functions appeared in BSD 4.2

BUGS

These functions use a static data space; if the data is needed for future use, it should be copied before any subsequent calls overwrite it. Only the Internet protocols are currently understood.

This document was created by man2html, using the manual pages.
Time: 15:52:51 GMT, January 15, 2023