2000-02-18 03:39:52 +08:00
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\input texinfo.tex
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@setfilename libc.info
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@ifinfo
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@format
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2015-03-13 01:22:23 +08:00
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@dircategory Newlib
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@direntry
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* libc: (libc). The ANSI C library.
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@end direntry
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2000-02-18 03:39:52 +08:00
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@end format
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@end ifinfo
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@ifinfo
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This file documents the ANSI C library.
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2014-12-19 04:30:11 +08:00
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Copyright (C) 1992, 1993, 1994-2014 Red Hat, Inc.
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2000-02-18 03:39:52 +08:00
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@file{libc} includes software developed by the
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University of California, Berkeley and its contributors.
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libc includes software developed by Martin Jackson, Graham Haley
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and Steve Chamberlain of Tadpole Technology and released to Cygnus.
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2003-10-21 02:46:38 +08:00
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libc uses floating-point conversion software developed at AT&T, which
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2000-02-18 03:39:52 +08:00
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includes this copyright information:
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The author of this software is David M. Gay.
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Copyright (c) 1991 by AT&T.
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Permission to use, copy, modify, and distribute this software for any
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purpose without fee is hereby granted, provided that this entire notice
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is included in all copies of any software which is or includes a copy
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or modification of this software and in all copies of the supporting
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documentation for such software.
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THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
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WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR AT&T MAKES ANY
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REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
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OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
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Permission is granted to make and distribute verbatim copies of
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this manual provided the copyright notice and this permission notice
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are preserved on all copies.
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@ignore
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Permission is granted to process this file through Tex and print the
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results, provided the printed document carries copying permission
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notice identical to this one except for the removal of this paragraph
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(this paragraph not being relevant to the printed manual).
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@end ignore
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Permission is granted to copy and distribute modified versions of this
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manual under the conditions for verbatim copying, subject to the terms
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of the GNU General Public License, which includes the provision that the
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entire resulting derived work is distributed under the terms of a
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permission notice identical to this one.
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Permission is granted to copy and distribute translations of this manual
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into another language, under the above conditions for modified versions.
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@end ifinfo
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@iftex
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@c @smallbook
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@c @cropmarks
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@finalout
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@setchapternewpage odd
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2002-07-23 00:40:48 +08:00
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@settitle Red Hat newlib C Library, Full
|
2000-02-18 03:39:52 +08:00
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@titlepage
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2002-07-23 00:40:48 +08:00
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@title The Red Hat newlib C Library
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2000-02-18 03:39:52 +08:00
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@subtitle Full Configuration
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@sp 1
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2024-01-01 01:00:18 +08:00
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@subtitle @code{libc} 4.4.0
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@subtitle December 2023
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2023-12-17 17:01:45 +08:00
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@author Steve Chamberlain
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@author Roland Pesch
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@author Red Hat Support
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@author Jeff Johnston
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2000-02-18 03:39:52 +08:00
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@page
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@tex
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{\parskip=0pt
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2004-01-07 03:26:10 +08:00
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sac@@cygnus.com, pesch@@cygnus.com, jjohnstn@@redhat.com\hfill {\it The Red Hat newlib C Library}\par
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Copyright \copyright{} 1992, 1993, 1994-2004 Red Hat Inc.
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2000-02-18 03:39:52 +08:00
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}
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\global\parindent=0pt % Steve likes it this way
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@end tex
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@file{libc} includes software developed by the
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University of California, Berkeley and its contributors.
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@file{libc} includes software developed by Martin Jackson, Graham Haley
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and Steve Chamberlain of Tadpole Technology and released to Cygnus.
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2003-10-21 02:46:38 +08:00
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@file{libc} uses floating-point conversion software developed at AT&T,
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2000-02-18 03:39:52 +08:00
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which includes this copyright information:
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@cartouche
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@quotation
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The author of this software is David M. Gay.
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Copyright (c) 1991 by AT&T.
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Permission to use, copy, modify, and distribute this software for any
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purpose without fee is hereby granted, provided that this entire notice
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is included in all copies of any software which is or includes a copy
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or modification of this software and in all copies of the supporting
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documentation for such software.
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THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
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WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR AT&T MAKES ANY
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REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
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OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
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@end quotation
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@end cartouche
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Permission is granted to make and distribute verbatim copies of
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this manual provided the copyright notice and this permission notice
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are preserved on all copies.
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Permission is granted to copy and distribute modified versions of this
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manual under the conditions for verbatim copying, subject to the terms
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of the GNU General Public License, which includes the provision that the
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entire resulting derived work is distributed under the terms of a
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permission notice identical to this one.
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Permission is granted to copy and distribute translations of this manual
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into another language, under the above conditions for modified versions.
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@end titlepage
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@end iftex
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2005-10-15 02:45:19 +08:00
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@ifnottex
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2000-02-18 03:39:52 +08:00
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@node Top
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2002-07-23 00:40:48 +08:00
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@top The Red Hat newlib C Library
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2000-02-18 03:39:52 +08:00
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@menu
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2005-10-15 02:45:19 +08:00
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* Introduction::
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2000-02-18 03:39:52 +08:00
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* Stdlib::
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* Ctype::
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* Stdio::
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2002-07-18 07:25:44 +08:00
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* Stdio64::
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2000-02-18 03:39:52 +08:00
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* Strings::
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2002-08-30 03:47:43 +08:00
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* Wchar strings::
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2000-02-18 03:39:52 +08:00
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* Signals::
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* Timefns::
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* Locale::
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2005-10-15 02:45:19 +08:00
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* Reentrancy::
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2002-07-16 23:30:32 +08:00
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2000-02-18 03:39:52 +08:00
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* Misc::
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2009-08-19 20:38:09 +08:00
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* Posix::
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2005-10-15 02:45:19 +08:00
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* Syscalls::
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2000-02-18 03:39:52 +08:00
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* Arglists::
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2022-12-10 16:27:58 +08:00
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* Encoding conversions::
|
2017-11-29 08:11:59 +08:00
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* Overflow Protection::
|
2004-01-23 Artem B. Bityuckiy <abitytsky@softminecorp.com>
* acinclude.m4 (--enable-newlib-iconv): New configuration option.
(--enable-newlib-builtin-converters): Ditto.
* configure.in: Add code to set _ICONV_ENABLED flag.
Set _MB_LEN_MAX to 1 if not mb enabled.
* configure: Regenerated.
* aclocal.m4: Ditto.
* Makefile.in: Ditto.
* newlib.hin: Add _ICONV_ENABLED flag.
* libc/Makefile.am: Add support for iconv.
* libc/configure.in: Ditto.
* libc/Makefile.in: Regenerated.
* libc/aclocal.m4: Ditto.
* libc/configure: Ditto.
* libc/libc.texinfo: Add iconv documentation.
* libc/iconv/AUTHORS, libc/iconv/COPYING, libc/iconv/Makefile.am,
libc/iconv/Makefile.in, libc/iconv/README.ORIGINAL,
libc/iconv/README.TODO, libc/iconv/charset.aliases,
libc/iconv/iconv.tex, libc/iconv/ccs/Makefile.am,
libc/iconv/ccs/Makefile.in, libc/iconv/ccs/README.CCS.SOURCES,
libc/iconv/ccs/big5.c, libc/iconv/ccs/cns11643_plane1.c,
libc/iconv/ccs/cns11643_plane14.c, libc/iconv/ccs/cns11643_plane2.c,
libc/iconv/ccs/cp775.c, libc/iconv/ccs/cp850.c,
libc/iconv/ccs/cp852.c, libc/iconv/ccs/cp855.c,
libc/iconv/ccs/cp866.c, libc/iconv/ccs/gb_2312_80.c,
libc/iconv/ccs/iconv_mktbl, libc/iconv/ccs/iso_8859_1.c,
libc/iconv/ccs/iso_8859_15.c, libc/iconv/ccs/iso_8859_2.c,
libc/iconv/ccs/iso_8859_4.c, libc/iconv/ccs/iso_8859_5.c,
libc/iconv/ccs/jis_x0201.c, libc/iconv/ccs/jis_x0208_1983.c,
libc/iconv/ccs/jis_x0212_1990.c, libc/iconv/ccs/koi8_r.c,
libc/iconv/ccs/koi8_u.c, libc/iconv/ccs/ksx1001.c,
libc/iconv/ccs/shift_jis.c, libc/iconv/ccs/us_ascii.c,
libc/iconv/ccs/binary/Makefile.am, libc/iconv/ccs/binary/Makefile.in,
libc/iconv/ccs/binary/big5.cct,
libc/iconv/ccs/binary/cns11643_plane1.cct,
libc/iconv/ccs/binary/cns11643_plane14.cct,
libc/iconv/ccs/binary/cns11643_plane2.cct,
libc/iconv/ccs/binary/cp775.cct, libc/iconv/ccs/binary/cp850.cct,
libc/iconv/ccs/binary/cp852.cct, libc/iconv/ccs/binary/cp855.cct,
libc/iconv/ccs/binary/cp866.cct, libc/iconv/ccs/binary/gb_2312_80.cct,
libc/iconv/ccs/binary/iso_8859_1.cct,
libc/iconv/ccs/binary/iso_8859_15.cct,
libc/iconv/ccs/binary/iso_8859_2.cct,
libc/iconv/ccs/binary/iso_8859_4.cct,
libc/iconv/ccs/binary/iso_8859_5.cct,
libc/iconv/ccs/binary/jis_x0201.cct,
libc/iconv/ccs/binary/jis_x0208_1983.cct,
libc/iconv/ccs/binary/jis_x0212_1990.cct,
libc/iconv/ccs/binary/koi8_r.cct, libc/iconv/ccs/binary/koi8_u.cct,
libc/iconv/ccs/binary/ksx1001.cct,
libc/iconv/ccs/binary/shift_jis.cct,
libc/iconv/ccs/binary/us_ascii.cct,
libc/iconv/ces/Makefile.am, libc/iconv/ces/Makefile.in,
libc/iconv/ces/euc-jp.c, libc/iconv/ces/euc-kr.c,
libc/iconv/ces/euc-tw.c, libc/iconv/ces/gb2312.c,
libc/iconv/ces/iso-10646-ucs-2.c, libc/iconv/ces/iso-10646-ucs-4.c,
libc/iconv/ces/ucs-2-internal.c, libc/iconv/ces/ucs-4-internal.c,
libc/iconv/ces/utf-16.c, libc/iconv/ces/utf-8.c,
libc/iconv/lib/Makefile.am, libc/iconv/lib/Makefile.in,
libc/iconv/lib/aliases.c, libc/iconv/lib/bialiasesi.c,
libc/iconv/lib/biccs.c, libc/iconv/lib/bices.c,
libc/iconv/lib/ccs.c, libc/iconv/lib/ces.c,
libc/iconv/lib/ces_euc.c, libc/iconv/lib/ces_iso2022.c,
libc/iconv/lib/ces_table.c, libc/iconv/lib/converter.c,
libc/iconv/lib/deps.h, libc/iconv/lib/endian.h,
libc/iconv/lib/iconv.c, libc/iconv/lib/loaddata.c,
libc/iconv/lib/local.h, libc/include/iconv.h: New files.
* libc/sys/linux/include/iconv.h: Ditto.
* libc/include/sys/_types.h (_iconv_t): Added.
* doc/aclocal.m4: Regenerated.
* doc/configure: Ditto.
* doc/Makefile.in: Ditto.
* iconvdata/Makefile.in: Ditto.
* iconvdata/aclocal.m4: Ditto.
* iconvdata/configure: Ditto.
* libc/*aclocal.m4: Ditto.
* libc/*Makefile.in: Ditto.
* libc/*configure: Ditto.
* libm/*aclocal.m4: Ditto.
* libm/*Makefile.in: Ditto.
* libm/*configure: Ditto.
2004-01-24 05:37:46 +08:00
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2013-11-08 20:48:29 +08:00
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* Document Index::
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2024-01-05 13:00:22 +08:00
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* Function Index::
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2000-02-18 03:39:52 +08:00
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@end menu
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2005-10-15 02:45:19 +08:00
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@end ifnottex
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@node Introduction
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@chapter Introduction
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This reference manual describes the functions provided by the Red Hat
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``newlib'' version of the standard ANSI C library. This document is not
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intended as an overview or a tutorial for the C library. Each library
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function is listed with a synopsis of its use, a brief description,
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return values (including error handling), and portability issues.
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Some of the library functions depend on support from the underlying
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operating system and may not be available on every platform. For
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embedded systems in particular, many of these underlying operating
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system services may not be available or may not be fully functional.
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The specific operating system subroutines required for a particular
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library function are listed in the ``Portability'' section of the
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function description. @xref{Syscalls}, for a description of the
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relevant operating system calls.
|
2000-02-18 03:39:52 +08:00
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@include targetdep.tex
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@node Arglists
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@chapter Variable Argument Lists
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The @code{printf} family of functions is defined to accept a variable
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number of arguments, rather than a fixed argument list. You can define
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your own functions with a variable argument list, by using macro
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definitions from either @file{stdarg.h} (for compatibility with ANSI C)
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or from @file{varargs.h} (for compatibility with a popular convention
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prior to ANSI C).
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@menu
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* Stdarg::
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* Varargs::
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@end menu
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@node Stdarg
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@section ANSI-standard macros, @file{stdarg.h}
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In ANSI C, a function has a variable number of arguments when its
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parameter list ends in an ellipsis (@code{...}). The parameter list
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must also include at least one explicitly named argument; that argument
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is used to initialize the variable list data structure.
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ANSI C defines three macros (@code{va_start}, @code{va_arg}, and
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@code{va_end}) to operate on variable argument lists. @file{stdarg.h}
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also defines a special type to represent variable argument lists: this
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type is called @code{va_list}.
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@menu
|
2024-01-05 13:01:23 +08:00
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* Function va_start::
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* Function va_arg::
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* Function va_end::
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2000-02-18 03:39:52 +08:00
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@end menu
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@page
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2024-01-05 13:01:23 +08:00
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@node Function va_start
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2000-02-18 03:39:52 +08:00
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@subsection Initialize variable argument list
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@findex va_start
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@strong{Synopsis}
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@example
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#include <stdarg.h>
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void va_start(va_list @var{ap}, @var{rightmost});
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@end example
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@strong{Description}@*
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Use @code{va_start} to initialize the variable argument list @var{ap},
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so that @code{va_arg} can extract values from it. @var{rightmost} is
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|
the name of the last explicit argument in the parameter list (the
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argument immediately preceding the ellipsis @samp{...} that flags
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|
variable arguments in an ANSI C function header). You can only use
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@code{va_start} in a function declared using this ellipsis notation
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(not, for example, in one of its subfunctions).
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@strong{Returns}@*
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@code{va_start} does not return a result.
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@strong{Portability}@*
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|
ANSI C requires @code{va_start}.
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@page
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2024-01-05 13:01:23 +08:00
|
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@node Function va_arg
|
2000-02-18 03:39:52 +08:00
|
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@subsection Extract a value from argument list
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@findex va_arg
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@strong{Synopsis}
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@example
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|
#include <stdarg.h>
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@var{type} va_arg(va_list @var{ap}, @var{type});
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@end example
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@strong{Description}@*
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|
@code{va_arg} returns the next unprocessed value from a variable
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argument list @var{ap} (which you must previously create with
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@var{va_start}). Specify the type for the value as the second parameter
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to the macro, @var{type}.
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You may pass a @code{va_list} object @var{ap} to a subfunction, and use
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|
@code{va_arg} from the subfunction rather than from the function
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|
actually declared with an ellipsis in the header; however, in that case
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you may @emph{only} use @code{va_arg} from the subfunction. ANSI C does
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|
|
not permit extracting successive values from a single variable-argument
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list from different levels of the calling stack.
|
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|
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|
There is no mechanism for testing whether there is actually a next
|
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|
|
argument available; you might instead pass an argument count (or some
|
|
|
|
other data that implies an argument count) as one of the fixed arguments
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|
|
in your function call.
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|
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@strong{Returns}@*
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|
@code{va_arg} returns the next argument, an object of type @var{type}.
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|
@strong{Portability}@*
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ANSI C requires @code{va_arg}.
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|
|
|
@page
|
2024-01-05 13:01:23 +08:00
|
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@node Function va_end
|
2000-02-18 03:39:52 +08:00
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|
@subsection Abandon a variable argument list
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|
@findex va_end
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|
|
|
@strong{Synopsis}
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|
|
@example
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|
|
|
#include <stdarg.h>
|
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|
void va_end(va_list @var{ap});
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|
@end example
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|
@strong{Description}@*
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|
Use @code{va_end} to declare that your program will not use the variable
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|
|
argument list @var{ap} any further.
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|
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|
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@strong{Returns}@*
|
|
|
|
@code{va_end} does not return a result.
|
|
|
|
|
|
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|
@strong{Portability}@*
|
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|
|
ANSI C requires @code{va_end}.
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|
@node Varargs
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|
@section Traditional macros, @file{varargs.h}
|
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|
|
|
|
|
|
If your C compiler predates ANSI C, you may still be able to use
|
|
|
|
variable argument lists using the macros from the @file{varargs.h}
|
|
|
|
header file. These macros resemble their ANSI counterparts, but have
|
|
|
|
important differences in usage. In particular, since traditional C has
|
|
|
|
no declaration mechanism for variable argument lists, two additional
|
|
|
|
macros are provided simply for the purpose of defining functions with
|
|
|
|
variable argument lists.
|
|
|
|
|
|
|
|
As with @file{stdarg.h}, the type @code{va_list} is used to hold a data
|
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|
|
structure representing a variable argument list.
|
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|
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|
|
|
@menu
|
2024-01-05 13:01:23 +08:00
|
|
|
* Function va_alist::
|
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|
|
* Function va_start-trad::
|
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|
* Function va_arg-trad::
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|
|
* Function va_end-trad::
|
2000-02-18 03:39:52 +08:00
|
|
|
@end menu
|
|
|
|
|
|
|
|
@page
|
2024-01-05 13:01:23 +08:00
|
|
|
@node Function va_alist
|
2000-02-18 03:39:52 +08:00
|
|
|
@subsection Declare variable arguments
|
|
|
|
@findex va_alist
|
|
|
|
@findex va_dcl
|
|
|
|
@strong{Synopsis}
|
|
|
|
@example
|
|
|
|
#include <varargs.h>
|
|
|
|
@var{function}(va_alist)
|
|
|
|
va_dcl
|
|
|
|
@end example
|
|
|
|
|
|
|
|
@strong{Description}@*
|
|
|
|
To use the @file{varargs.h} version of variable argument lists, you must
|
|
|
|
declare your function with a call to the macro @code{va_alist} as its
|
|
|
|
argument list, and use @code{va_dcl} as the declaration. @emph{Do not
|
|
|
|
use a semicolon after @code{va_dcl}.}
|
|
|
|
|
|
|
|
@strong{Returns}@*
|
|
|
|
These macros cannot be used in a context where a return is syntactically
|
|
|
|
possible.
|
|
|
|
|
|
|
|
@strong{Portability}@*
|
|
|
|
@var{va_alist} and @var{va_dcl} were the most widespread method of
|
|
|
|
declaring variable argument lists prior to ANSI C.
|
|
|
|
|
|
|
|
@page
|
2024-01-05 13:01:23 +08:00
|
|
|
@node Function va_start-trad
|
2000-02-18 03:39:52 +08:00
|
|
|
@subsection Initialize variable argument list
|
|
|
|
@findex va_start
|
|
|
|
@strong{Synopsis}
|
|
|
|
@example
|
|
|
|
#include <varargs.h>
|
|
|
|
va_list @var{ap};
|
|
|
|
va_start(@var{ap});
|
|
|
|
@end example
|
|
|
|
|
|
|
|
@strong{Description}@*
|
|
|
|
With the @file{varargs.h} macros, use @code{va_start} to initialize a
|
|
|
|
data structure @var{ap} to permit manipulating a variable argument list.
|
|
|
|
@var{ap} must have the type @var{va_alist}.
|
|
|
|
|
|
|
|
@strong{Returns}@*
|
|
|
|
@code{va_start} does not return a result.
|
|
|
|
|
|
|
|
@strong{Portability}@*
|
|
|
|
@code{va_start} is also defined as a macro in ANSI C, but the
|
|
|
|
definitions are incompatible; the ANSI version has another parameter
|
|
|
|
besides @var{ap}.
|
|
|
|
|
|
|
|
@page
|
2024-01-05 13:01:23 +08:00
|
|
|
@node Function va_arg-trad
|
2000-02-18 03:39:52 +08:00
|
|
|
@subsection Extract a value from argument list
|
|
|
|
@findex va_arg
|
|
|
|
@strong{Synopsis}
|
|
|
|
@example
|
|
|
|
#include <varargs.h>
|
|
|
|
@var{type} va_arg(va_list @var{ap}, @var{type});
|
|
|
|
@end example
|
|
|
|
|
|
|
|
@strong{Description}@*
|
|
|
|
@code{va_arg} returns the next unprocessed value from a variable
|
|
|
|
argument list @var{ap} (which you must previously create with
|
|
|
|
@var{va_start}). Specify the type for the value as the second parameter
|
|
|
|
to the macro, @var{type}.
|
|
|
|
|
|
|
|
@strong{Returns}@*
|
|
|
|
@code{va_arg} returns the next argument, an object of type @var{type}.
|
|
|
|
|
|
|
|
@strong{Portability}@*
|
|
|
|
The @code{va_arg} defined in @file{varargs.h} has the same syntax and
|
|
|
|
usage as the ANSI C version from @file{stdarg.h}.
|
|
|
|
|
|
|
|
@page
|
2024-01-05 13:01:23 +08:00
|
|
|
@node Function va_end-trad
|
2000-02-18 03:39:52 +08:00
|
|
|
@subsection Abandon a variable argument list
|
|
|
|
@findex va_end
|
|
|
|
@strong{Synopsis}
|
|
|
|
@example
|
|
|
|
#include <varargs.h>
|
|
|
|
va_end(va_list @var{ap});
|
|
|
|
@end example
|
|
|
|
|
|
|
|
@strong{Description}@*
|
|
|
|
Use @code{va_end} to declare that your program will not use the variable
|
|
|
|
argument list @var{ap} any further.
|
|
|
|
|
|
|
|
@strong{Returns}@*
|
|
|
|
@code{va_end} does not return a result.
|
|
|
|
|
|
|
|
@strong{Portability}@*
|
|
|
|
The @code{va_end} defined in @file{varargs.h} has the same syntax and
|
|
|
|
usage as the ANSI C version from @file{stdarg.h}.
|
|
|
|
|
2013-11-08 20:48:29 +08:00
|
|
|
@node Document Index
|
|
|
|
@unnumbered Document Index
|
2000-02-18 03:39:52 +08:00
|
|
|
@printindex cp
|
|
|
|
|
2024-01-05 13:00:22 +08:00
|
|
|
@node Function Index
|
|
|
|
@unnumbered Function Index
|
|
|
|
@printindex fn
|
|
|
|
|
2000-02-18 03:39:52 +08:00
|
|
|
@tex
|
2013-04-30 04:02:34 +08:00
|
|
|
% I think something like @@colophon should be in texinfo. In the
|
2000-02-18 03:39:52 +08:00
|
|
|
% meantime:
|
|
|
|
\long\def\colophon{\hbox to0pt{}\vfill
|
|
|
|
\centerline{The body of this manual is set in}
|
|
|
|
\centerline{\fontname\tenrm,}
|
|
|
|
\centerline{with headings in {\bf\fontname\tenbf}}
|
|
|
|
\centerline{and examples in {\tt\fontname\tentt}.}
|
|
|
|
\centerline{{\it\fontname\tenit\/} and}
|
|
|
|
\centerline{{\sl\fontname\tensl\/}}
|
|
|
|
\centerline{are used for emphasis.}\vfill}
|
|
|
|
\page\colophon
|
2013-04-30 04:02:34 +08:00
|
|
|
% Blame: pesch@@cygnus.com, 28mar91.
|
2000-02-18 03:39:52 +08:00
|
|
|
@end tex
|
|
|
|
|
|
|
|
@contents
|
|
|
|
@bye
|
|
|
|
|
|
|
|
|