PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

ENDSERVENT(3P)            POSIX Programmer's Manual           ENDSERVENT(3P)

PROLOG         top

       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         top

       endservent, getservbyname, getservbyport, getservent, setservent —
       network services database functions

SYNOPSIS         top

       #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         top

       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 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         top

       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.

       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         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

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

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       endhostent(3p), endprotoent(3p), htonl(3p), inet_addr(3p)

       The Base Definitions volume of POSIX.1‐2008, netdb.h(0p)

COPYRIGHT         top

       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 Electrical 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.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                      ENDSERVENT(3P)

Pages that refer to this page: netdb.h(0p)endhostent(3p)freeaddrinfo(3p)getnameinfo(3p)getservbyname(3p)htonl(3p)setservent(3p)