endprotoent(3p) — Linux manual page

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

       endprotoent, getprotobyname, getprotobynumber, getprotoent,
       setprotoent — network protocol database functions

SYNOPSIS

       #include <netdb.h>

       void endprotoent(void);
       struct protoent *getprotobyname(const char *name);
       struct protoent *getprotobynumber(int proto);
       struct protoent *getprotoent(void);
       void setprotoent(int stayopen);

DESCRIPTION

       These functions shall retrieve information about protocols. 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 setprotoent() 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 connection to the network
       protocol database shall not be closed after each call to
       getprotoent() (either directly, or indirectly through one of the
       other getproto*() functions), and the implementation may maintain
       an open file descriptor for the database.

       The getprotobyname() function shall search the database from the
       beginning and find the first entry for which the protocol name
       specified by name matches the p_name member, opening and closing
       a connection to the database as necessary.

       The getprotobynumber() function shall search the database from
       the beginning and find the first entry for which the protocol
       number specified by proto matches the p_proto member, opening and
       closing a connection to the database as necessary.

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

       The getprotobyname(), getprotobynumber(), and getprotoent()
       functions shall each return a pointer to a protoent structure,
       the members of which shall contain the fields of an entry in the
       network protocol database.

       The endprotoent() function shall close the connection to the
       database, releasing any open file descriptor.

       These functions need not be thread-safe.

RETURN VALUE

       Upon successful completion, getprotobyname(), getprotobynumber(),
       and getprotoent() return a pointer to a protoent 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
       getprotobyname(), getprotobynumber(), or getprotoent().  The
       returned pointer, and pointers within the structure, might also
       be invalidated if the calling thread is terminated.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       The Base Definitions volume of POSIX.1‐2017, netdb.h(0p)

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 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 .

       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               2017                   ENDPROTOENT(3P)

Pages that refer to this page: netdb.h(0p), endservent(3p), getprotobyname(3p), getsockopt(3p), setprotoent(3p), setsockopt(3p)

---