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# getservent

    GETSERVENT(3)           System Library Functions Manual          GETSERVENT(3)

    NAME
         getservent, getservbyport, getservbyname, setservent, endservent - get
         service entry

    SYNOPSIS
         #include <netdb.h>

         struct servent *
         getservent(void);

         struct servent *
         getservbyname(char *name, char *proto);

         struct servent *
         getservbyport(int port, char *proto);

         void
         setservent(int stayopen);

         void
         endservent(void);

    DESCRIPTION
         The getservent(), getservbyname(), and getservbyport() functions each
         return a pointer to an object with the following structure containing the
         broken-out fields of a line in the network services database,
         /etc/services.

               struct  servent {
                       char    *s_name;        /* official name of service */
                       char    **s_aliases;    /* alias list */
                       int     s_port;         /* port service resides at */
                       char    *s_proto;       /* protocol to use */
               };

         The members of this structure are:

         s_name     The official name of the service.

         s_aliases  A zero-terminated list of alternate names for the service.

         s_port     The port number at which the service resides.  Port numbers
                    are returned in network byte order.

         s_proto    The name of the protocol to use when contacting the service.

         The getservent() function reads the next line of the file, opening the
         file if necessary.

         The setservent() function opens and rewinds the file.  If the stayopen
         flag is non-zero, the net database will not be closed after each call to
         getservbyname() or getservbyport().

         The endservent() function closes the file.

         The getservbyname() and getservbyport() functions sequentially search
         from the beginning of the file until a matching protocol name or port
         number (specified in network byte order) is found, or until EOF is
         encountered.  If a protocol name is also supplied (non-null), searches
         must also match the protocol.

    FILES
         /etc/services

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

    SEE ALSO
         getprotoent(3), services(5)

    HISTORY
         The getservent(), getservbyport(), getservbyname(), setservent(), and
         endservent() functions appeared in 4.2BSD.

    BUGS
         These functions use static data storage; if the data is needed for future
         use, it should be copied before any subsequent calls overwrite it.
         Expecting port numbers to fit in a 32-bit quantity is probably naive.

    BSD                            January 12, 1994                            BSD

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