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 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 nonzero, 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), getprotoent_r(3), getservent(3), protocols(5)

COLOPHON
       This page is part of release 3.25 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)