GETPROTOENT

C Interface

        #include <netdb.h>



        struct protoent *getprotoent()



        struct protoent *getprotobyname(name)

        char *name;



        struct protoent *getprotobynumber(proto)

        int proto;



        setprotoent(stayopen)

        int stayopen;



        endprotoent()

Description

The getprotoent, getprotobyname, and getprotobynumber subroutines each return a pointer to an object with the following structure. This structure contains fields found in the network protocol database, /etc/protocols.

   struct    protoent {

        char *p_name;        /* official name of protocol */

        char **p_aliases;    /* alias list                */

        long p_proto;        /* protocol number           */

   };

The members of this structure are as follows:

p_name: The official name of the protocol.
p_aliases: A null-terminated list of alternate names for the protocol.
p_proto: The protocol number.

The getprotoent subroutine reads the next line of the file, opening the file if necessary.

The setprotoent subroutine opens and rewinds the file. If the stayopen flag is non-zero, the protocol database is not closed after each call to getprotoent (either directly or indirectly through one of the other getproto calls).

The endprotoent subroutine closes the file.

The getprotobyname and getprotobynumber subroutines sequentially search from the beginning of the file until a protocol name matching the parameter name or a protocol number matching the parameter proto is found, or until EOF is encountered.

Restrictions

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.

Return Value

The getprotoent, getprotobyname, and getprotobynumber subroutines return a null pointer (0) on EOF or when they are unable to open PROTOCOL.NET.SYS.

MPE/iX Specific

The name of the protocols file on MPE/iX is PROTOCOL.NET.SYS, as opposed to /etc/protocols on HP-UX.

Author

UCB (University of California at Berkeley)

Files

PROTOCOL.NET.SYS