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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