posix man page for getservent

ENDSERVENT(P)						     POSIX Programmer's Manual						     ENDSERVENT(P)

NAME
       endservent, getservbyname, getservbyport, getservent, setservent - network services database functions

SYNOPSIS
       #include <netdb.h>

       void endservent(void);
       struct servent *getservbyname(const char *name, const char *proto);
       struct servent *getservbyport(int port, const char *proto);
       struct servent *getservent(void);
       void setservent(int stayopen);

DESCRIPTION
       These  functions  shall retrieve information about network services.  This information is considered to be stored in a database that can be
       accessed sequentially or randomly. The implementation of this database is unspecified.

       The setservent() function shall open a connection to the database, and set the next entry to the first entry. If the stayopen  argument	is
       non-zero,  the net database shall not be closed after each call to the getservent() function (either directly, or indirectly through one of
       the other getserv*() functions), and the implementation may maintain an open file descriptor for the database.

       The getservent() function shall read the next entry of the database, opening and closing a connection to the database as necessary.

       The getservbyname() function shall search the database from the beginning and find the first entry for which the service name specified	by
       name matches the s_name member and the protocol name specified by proto matches the s_proto member, opening and closing a connection to the
       database as necessary. If proto is a null pointer, any value of the s_proto member shall be matched.

       The getservbyport() function shall search the database from the beginning and find the first entry for which the  port  specified  by  port
       matches	the  s_port  member  and  the protocol name specified by proto matches the s_proto member, opening and closing a connection to the
       database as necessary. If proto is a null pointer, any value of the s_proto member shall be matched. The port argument shall be in  network
       byte order.

       The  getservbyname(),  getservbyport(), and getservent() functions shall each return a pointer to a servent structure, the members of which
       shall contain the fields of an entry in the network services database.

       The endservent() function shall close the database, releasing any open file descriptor.

       These functions need not be reentrant. A function that is not required to be reentrant is not required to be thread-safe.

RETURN VALUE
       Upon successful completion, getservbyname(), getservbyport(), and getservent() return a pointer to a servent  structure	if  the  requested
       entry  was found, and a null pointer if the end of the database was reached or the requested entry was not found. Otherwise, a null pointer
       is returned.

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       The port argument of getservbyport() need not be compatible with the port values of all address families.

       The getservbyname(), getservbyport(), and getservent() functions may return pointers to static data, which may be overwritten by subsequent
       calls to any of these functions.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       endhostent() , endprotoent() , htonl() , inet_addr() , the Base Definitions volume of IEEE Std 1003.1-2001, <netdb.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
       Electrical  and	Electronics  Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE
       and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can  be  obtained
       online at http://www.opengroup.org/unix/online.html .

IEEE
/The Open Group						       2003							     ENDSERVENT(P)