4.3BSD - /usr/man/cat3/getprotobynumber.0

GETPROTOENT(3N)                                                GETPROTOENT(3N)


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

SYNOPSIS
       #include <netdb.h>

       struct protoent *getprotoent()

       struct protoent *getprotobyname(name)
       char *name;

       struct protoent *getprotobynumber(proto)
       int proto;

       setprotoent(stayopen)
       int stayopen

       endprotoent()

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

       The members of this structure are:

       p_name     The official name of the protocol.

       p_aliases  A zero terminated list of alternate names for the  protocol.

       p_proto    The protocol number.

       Getprotoent reads the next line of the file, opening the file if neces‐
       sary.

       Setprotoent opens and rewinds the file.  If the stayopen flag  is  non-
       zero, the net data base will not be closed after each call to getproto���
       byname or getprotobynumber.

       Endprotoent closes the file.

       Getprotobyname and getprotobynumber sequentially search from the begin‐
       ning  of  the file until a matching protocol name or protocol number is
       found, or until EOF is encountered.

FILES
       /etc/protocols

SEE ALSO
       protocols(5)

DIAGNOSTICS
       Null pointer (0) returned on EOF or error.

BUGS
       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
       understood.


4.2 Berkeley Distribution        May 19, 1986                  GETPROTOENT(3N)