getprotoent(SLIB)              6 January 1993              getprotoent(SLIB)


 Name

    endprotoent, getprotoent, getprotobyaddr, getprotobyname, setprotoent -
    get protocol entry

 Syntax


    #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 returns 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:

    pname     The official name of the protocol.

    paliases  A null-terminated list of alternate names for the protocol.

    pproto    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

 Diagnostics

    Null pointer (0) returned on EOF or error.

 Notes

    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.

 See also

    protocols(SFF)