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Sun Nov 10 02:37:15 1996 Ulrich Drepper <drepper@cygnus.com> * inet/gethstent_r.c: Update copyright. * nss/getXXbyYY_r.c: Likewise. * nss/nsswitch.c: Likewise. * nss/getXXent_r.c: Likewise. * nss/nss_files/files-XXX.c: Likewise. * nss/nss_files/files-netgroup.c: Likewise. * nss/nss_files/files-parse.c: Likewise. * nss/getXXent_r.c: Change implementation. It's not necessary to call all setXXent functions. Just find first available and when necessary let getXXent_r call the others. * nss/nss_files/files-XXX.c: Make really reentrant. Now calls of getXXent and getXXbyYY can be mixed. The cursor for traversing the database with getXXent will be remembered. * stdlib/test-canon.c (cwd): Change size to PATH_MAX. Sat Nov 9 15:34:48 1996 Ulrich Drepper <drepper@cygnus.com> * sysdeps/unix/sysv/linux/Dist: Add sys/mtio.h. * sysdeps/unix/sysv/linux/sys/mtio.h: New file. * signal/signal.h [__USE_BSD]: Add prototype for siggetmask. Fri Nov 8 13:29:30 1996 Ulrich Drepper <drepper@cygnus.com> * ctype/ctype.h (__isascii): Don't test for seventh bit not to be set. Instead for none beside the first seven bits to be set. X/Open allows the argument to be an `int' value. Reported by Alain Williams <addw@phcomp.co.uk>. (toascii, isascii): Define macro also when __USE_XOPEN. * sysdeps/posix/fpathconf.c: Use fstatfs to compute NAME_MAX, not PATH_MAX. Thu Nov 7 03:04:29 1996 Ulrich Drepper <drepper@cygnus.com> * nss/getXXXent_r.c (SETFUNC_NAME): Reset `nip' after loop to NULL so that GETFUNC will see first entry. (ENDFUNC_NAME): Likewise. Rewrite Netgroups implementation to avoid global data. * inet/netgroup.h: Add definition of name_list and struct __netgrent. Add prototypes for internal netgroup functions. * nss/nss_files/files-netgroup.c (_nss_files_setnetgrent): Take extra argument and use the included data instead of global vars. (_nss_files_endnetgrent): Likewise. (_nss_netgroup_parseline): Change to be static and use data included in the RESULT structure. * inet/getnetgrent_r.c (startp): Move into setup function. (known_groups, needed_groups): new part of the __netgrent sruct. (freememory): Take extra argument and use included data. (__internal_endnetgrent): Likewise. (internal_setnetgrent): Renamed to __internal_setnetgrent_reuse and take extra argument. (__internal_setnetgrent): New function. Call __internal_setnetgrent_reuse after calling free_memory. (setnetgrent): Only call __internal_setnetgrent. (__getnetgrent_r): Split into two functions. __getnetgrent_r calls __internal_getnetgrent after locking. (innetgr): Use dynamic data only. I.e., innetgr now is fully reentrant. Thu Nov 7 00:15:14 1996 Ulrich Drepper <drepper@cygnus.com> * sysdeps/stub/setenv.c: Correct typo: unseenv -> unsetenv. Reported by Joshua Cowan <jcowan@jcowan.reslife.okstate.edu>. Wed Nov 6 13:13:37 1996 Ulrich Drepper <drepper@cygnus.com> * manual/creature.texi: Document that _GNU_SOURCE is no longer the default when no *_SOURCE macro is given. Reported by Karsten Weiss <karsten@addx.au.s.shuttle.de>. * NOTES: remade from manual/creature.texi. * manual/libc.texinfo: Add back line about GPL translation which somehow got lost. * Make-dist (dist.tar): Depend on README being updated. * rellns-sh: Correct thinko in removing leading /. Reported by Andreas Jaeger <aj@arthur.pfalz.de>. * pwd/fgetpwent_r.c: Recognize lines containing only names starting with `+' or `-' in parser. * grp/fgetgrent_r.c: Likewise. * shadow/sgetspent_r.c: Likewise. * nss/nss_files/files-spwd.c: Don't accept entries starting with `+' or `-'. * sysdeps/stub/lchown.c: New file.
124 lines
5.7 KiB
Plaintext
124 lines
5.7 KiB
Plaintext
Feature Test Macros
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-------------------
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The exact set of features available when you compile a source file
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is controlled by which "feature test macros" you define.
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If you compile your programs using `gcc -ansi', you get only the
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ANSI C library features, unless you explicitly request additional
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features by defining one or more of the feature macros. *Note GNU CC
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Command Options: (gcc.info)Invoking GCC, for more information about GCC
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options.
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You should define these macros by using `#define' preprocessor
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directives at the top of your source code files. These directives
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*must* come before any `#include' of a system header file. It is best
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to make them the very first thing in the file, preceded only by
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comments. You could also use the `-D' option to GCC, but it's better
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if you make the source files indicate their own meaning in a
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self-contained way.
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- Macro: _POSIX_SOURCE
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If you define this macro, then the functionality from the POSIX.1
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standard (IEEE Standard 1003.1) is available, as well as all of the
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ANSI C facilities.
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- Macro: _POSIX_C_SOURCE
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If you define this macro with a value of `1', then the
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functionality from the POSIX.1 standard (IEEE Standard 1003.1) is
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made available. If you define this macro with a value of `2',
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then both the functionality from the POSIX.1 standard and the
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functionality from the POSIX.2 standard (IEEE Standard 1003.2) are
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made available. This is in addition to the ANSI C facilities.
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- Macro: _BSD_SOURCE
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If you define this macro, functionality derived from 4.3 BSD Unix
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is included as well as the ANSI C, POSIX.1, and POSIX.2 material.
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Some of the features derived from 4.3 BSD Unix conflict with the
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corresponding features specified by the POSIX.1 standard. If this
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macro is defined, the 4.3 BSD definitions take precedence over the
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POSIX definitions.
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Due to the nature of some of the conflicts between 4.3 BSD and
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POSIX.1, you need to use a special "BSD compatibility library"
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when linking programs compiled for BSD compatibility. This is
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because some functions must be defined in two different ways, one
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of them in the normal C library, and one of them in the
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compatibility library. If your program defines `_BSD_SOURCE', you
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must give the option `-lbsd-compat' to the compiler or linker when
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linking the program, to tell it to find functions in this special
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compatibility library before looking for them in the normal C
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library.
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- Macro: _SVID_SOURCE
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If you define this macro, functionality derived from SVID is
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included as well as the ANSI C, POSIX.1, POSIX.2, and X/Open
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material.
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- Macro: _XOPEN_SOURCE
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If you define these macro, functionality described in the X/Open
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Portability Guide is included. This is an superset of the POSIX.1
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and POSIX.2 functionality and in fact `_POSIX_SOURCE' and
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`_POSIX_C_SOURCE' get automatically be defined.
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But as the great unifaction of all Unices there is also
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functionality only available in BSD and SVID is included.
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If the macro `_XOPEN_SOURCE_EXTENDED' is also defined, even more
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functionality is available. The extra functions will make all
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functions available which are necessary for the X/Open Unix brand.
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- Macro: _GNU_SOURCE
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If you define this macro, everything is included: ANSI C, POSIX.1,
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POSIX.2, BSD, SVID, X/Open, and GNU extensions. In the cases where
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POSIX.1 conflicts with BSD, the POSIX definitions take precedence.
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If you want to get the full effect of `_GNU_SOURCE' but make the
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BSD definitions take precedence over the POSIX definitions, use
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this sequence of definitions:
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#define _GNU_SOURCE
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#define _BSD_SOURCE
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#define _SVID_SOURCE
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Note that if you do this, you must link your program with the BSD
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compatibility library by passing the `-lbsd-compat' option to the
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compiler or linker. *Note:* If you forget to do this, you may get
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very strange errors at run time.
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- Macro: _REENTRANT,_THREAD_SAFE
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If you define one this macro, reentrant versions of several
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functions get declared. Some of the functions are specified in
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POSIX.1c but many others are only available on a few other systems
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or are unique to GNU libc. The problem is that the
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standardization of the thread safe C library interface still is
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behind.
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Unlike on some other systems no special version of the C library
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must be used for linking. There is only one version but while
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compiling this it must have been specified to compile as thread
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safe.
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We recommend you use `_GNU_SOURCE' in new programs. If you don't
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specify the `-ansi' option to GCC and don't define any of these macros
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explicitly, the effect is the same as defining `_POSIX_C_SOURCE' to 2
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and `_POSIX_SOURCE', `_SVID_SOURCE', and `_BSD_SOURCE' to 1.
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When you define a feature test macro to request a larger class of
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features, it is harmless to define in addition a feature test macro for
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a subset of those features. For example, if you define
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`_POSIX_C_SOURCE', then defining `_POSIX_SOURCE' as well has no effect.
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Likewise, if you define `_GNU_SOURCE', then defining either
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`_POSIX_SOURCE' or `_POSIX_C_SOURCE' or `_SVID_SOURCE' as well has no
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effect.
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Note, however, that the features of `_BSD_SOURCE' are not a subset of
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any of the other feature test macros supported. This is because it
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defines BSD features that take precedence over the POSIX features that
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are requested by the other macros. For this reason, defining
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`_BSD_SOURCE' in addition to the other feature test macros does have an
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effect: it causes the BSD features to take priority over the conflicting
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POSIX features.
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