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ENDSERVENT(3P)             POSIX Programmer's Manual            ENDSERVENT(3P)
PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
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  get-
       servent()  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  begin-
       ning  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 begin-
       ning 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  a  value
       obtained by converting a uint16_t in network byte order to int.
       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 thread-safe.
RETURN VALUE
       Upon successful completion, getservbyname(), getservbyport(), and  get-
       servent()  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.
       The application shall not modify the  structure  to  which  the  return
       value  points,  nor any storage areas pointed to by pointers within the
       structure. The returned pointer, and  pointers  within  the  structure,
       might  be  invalidated  or  the structure or the storage areas might be
       overwritten by a subsequent call to  getservbyname(),  getservbyport(),
       or getservent().
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.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       endhostent(), endprotoent(), htonl(), inet_addr()
       The Base Definitions volume of POSIX.1-2008, <netdb.h>
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal and Electronics Engineers,  Inc  and  The  Open  Group.   (This  is
       POSIX.1-2008  with  the  2013  Technical Corrigendum 1 applied.) 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.unix.org/online.html .
       Any  typographical  or  formatting  errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files  to  man page format. To report such errors, see https://www.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                       ENDSERVENT(3P)