GETPROTOENT(3)

NAME
getprotoent, getprotobyname, getprotobynumber, setprotoent, endprotoent - get protocol entry

SYNOPSIS
#include <netdb.h>

struct protoent *getprotoent(void);

struct protoent *getprotobyname(const char *name);

struct protoent *getprotobynumber(int proto);

void setprotoent(int stayopen);

void endprotoent(void);

DESCRIPTION
The getprotoent() function reads the next entry from the protocols database (see protocols(5)) and returns a protoent structure containing the broken-out fields from the entry. A connection is opened to the database if necessary.

The getprotobyname() function returns a protoent structure for the entry from the database that matches the protocol name name. A connection is opened to the database if necessary.

The getprotobynumber() function returns a protoent structure for the entry from the database that matches the protocol number number. A connection is opened to the database if necessary.

The setprotoent() function opens a connection to the database, and sets the next entry to the first entry. If stayopen is non-zero, then the connection to the database will not be closed between calls to one of the getproto*() functions.

The endprotoent() function closes the connection to the database.

The protoent structure is defined in <netdb.h> as follows:

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

The members of the protoent structure are:

p_name
    The official name of the protocol.

p_aliases
    A NULL-terminated list of alternative names for the protocol.

p_proto
    The protocol number.

RETURN VALUE
The getprotoent(), getprotobyname() and getprotobynumber() functions return a pointer to a statically allocated protoent structure, or a NULL pointer if an error occurs or the end of the file is reached.

FILES
/etc/protocols
    protocol database file

CONFORMING TO
4.3BSD, POSIX.1-2001.

SEE ALSO
getnetent(3), getprotent_r(3), getservent(3), protocols(5)

COLOPHON
This page is part of release 3.19 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.