getprotoent(3N)                                             getprotoent(3N)

NAME
     getprotoent, getprotobynumber, getprotobyname, setprotoent, endpro-
     toent - get entry in protocol file

SYNOPSIS
     #include <netdb.h>

     struct protoent *getprotoent(void);

     struct protoent *getprotobyname(const char *name);

     struct protoent *getprotobynumber(int proto);

     int setprotoent(int stayopen);

     int endprotoent(void);

DESCRIPTION
     getprotoent(), getprotobyname(), and getprotobynumber() 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 *pname;        /* official name of protocol */
          char **paliases;    /* alias list */
          int  pproto;        /* protocol number */
     };

     The members of this structure are:

     pname         The official name of the protocol.

     paliases      A zero terminated list of alternate names for the pro-
                    tocol.

     pproto        The protocol number.

     getprotoent() reads the next line of the file, opening the file if
     necessary.

     setprotoent() opens and positions the read pointer at the beginning of
     the file. If the stayopen flag is non-zero, the file will not be
     closed after each call to getprotoent() (either directly, or
     indirectly through one of the other "getproto" calls).

     endprotoent() closes the file.

     getprotobyname() and getprotobynumber() sequentially search from the
     beginning of the file until a matching protocol name or protocol
     number is found, or until an EOF is encountered.




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getprotoent(3N)                                             getprotoent(3N)

DIAGNOSTICS
     A NULL pointer is returned on an EOF or error.

     All information is contained in a static area so it must be copied if
     it is to be saved. Only the Internet protocols are currently under-
     stood.

FILES
     /etc/protocols

SEE ALSO
     protocols(4).










































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