GETPROTOENT(3) Linux Programmer s Manual 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 connec- tion 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 3.22 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/.

GNU 2008-08-19 GETPROTOENT(3)