1 GNU C Library NEWS -- history of user-visible changes. 28 March 1996
3 Copyright (C) 1992, 93, 94, 95, 96 Free Software Foundation, Inc.
4 See the end for copying conditions.
6 Please send GNU C library bug reports to bug-glibc@prep.ai.mit.edu.
10 * GNU extensions are no longer declared by default. To enable them you
11 must define the macro `_GNU_SOURCE' in your program or compile with
14 * The library has changed from using GNU ld symbol aliases to using weak
15 symbols where available. The ELF object file format supports weak
16 symbols; GNU ld also supports weak symbols in the a.out format. (There
17 is also now support for other GNU ld extensions in ELF. Use the
18 `--with-elf' option to configure to indicate you have ELF, and
19 `--with-gnu-ld' if using GNU ld.) This change resulted in the deletion
20 of many files which contained only symbol aliases, reducing the size of
21 the source and the compiled library; many other files were renamed to
22 less cryptic names previously occupied by the symbol alias files.
23 There is a new header file <elf.h> and new library `-lelf' for
24 programs which operate on files in the ELF format.
26 * Converted to Autoconf version 2, so `configure' has more options.
27 Run `configure --help' to see the details.
29 * The library can now be configured to build profiling, highly-optimized
30 (but undebuggable), and/or shared libraries (ELF with GNU ld only). The
31 `--enable-profile', `--enable-omitfp', and `--enable-shared' options to
32 `configure' enable building these extra libraries. The shared library is
33 built by default when using both ELF and GNU ld. When shared libraries
34 are enabled, the new library `-ldl' is available for arbitrary run-time
35 loading of shared objects; its interface is defined in <dlfcn.h>. The
36 new header file <link.h> gives access to the internals of the run-time
37 dynamic linker, `ld.so'.
39 * The C library now provides the run-time support code for profiling
40 executables compiled with `-pg'. Programs can control the profiling code
41 through the interface in <sys/gmon.h>. The `gmon.out' files written by
42 the GNU C library can be read only by GNU `gprof' (from GNU binutils);
43 the support for this file format was contributed by David Mosberger-Tang.
45 * The math code has been replaced with a math library based on fdlibm from
46 Sun, and modified by JT Conklin with i387 support and by Ian Taylor with
47 `float' functions. The math functions now reside in a separate library,
48 so programs using them will need to use `-lm' their linking commands.
50 * The new functions `strtoq' and `strtouq' parse integer values from
51 strings, like `strtol' and `strtoul', but they return `long long int' and
52 `unsigned long long int' values, respectively (64-bit quantities).
54 * The new functions `strtof' and `strtold' parse floating-point values from
55 strings, like `strtod', but they return `float' and `long double' values,
56 respectively (on some machines `double' and `long double' are the same).
58 * Ulrich Drepper has contributed new implementations of the floating-point
59 printing and reading code used in the `printf' family of functions and
60 `strtod', `strtof', and `strtold'. These new functions are perfectly
61 accurate, and much faster than the old ones.
63 * The new header <langinfo.h> defines an interface for accessing
64 various locale-dependent data (using the locale chosen with `setlocale').
66 * Ulrich Drepper has contributed a new suite of functions for operation on
67 wide-character and multibyte-character strings, in <wcstr.h> and <mbstr.h>;
68 and classification and case conversion of wide characters, in <wctype.h>.
69 These new functions are intended to conform to the ISO C specification.
71 * You can now use positional parameter specifications in format strings
72 for the `printf' and `scanf' families of functions. For example,
73 `printf ("Number %2$d, Mr %1$s\n", "Jones", 6);'' prints
74 ``Number 6, Mr Jones''. This is mainly useful when providing different
75 format strings for different languages, whose grammars may dictate
76 different orderings of the values being printed. To support this
77 feature, the interface for `register_printf_handler' has changed; see
78 the header file <printf.h> for details.
80 * The `printf' and `scanf' families of functions now understand a new
81 formatting flag for numeric conversions: the ' flag (e.g. %'d or %'f) says
82 to group numbers as indicated by the locale; for `scanf' and friends, this
83 says to accept as valid only a number with all the proper grouping
84 separators in the right places. In the default "C" locale, numbers are
85 not grouped; but locales for specific countries will define the usual
86 conventions (i.e. separate thousands with `,' in the US locale).
88 * The pgrp functions have been regularized, slightly incompatibly but much
89 less confusingly. The core functions are now `getpgid' and `setpgid',
90 which take arguments for the PID to operate on; the POSIX.1 `getpgrp' (no
91 argument) and BSD `setpgrp' (identical to `setpgid') functions are
92 provided for compatibility. There is no longer an incompatible `getpgrp'
93 with an argument declared under _BSD_SOURCE; no BSD code uses it.
95 * The new header file <fts.h> and suite of functions simplify programs that
96 operate on directory trees. This code comes from 4.4 BSD.
98 * The resolver code has been updated from the BIND 4.9.3 release.
100 * The new function `malloc_find_object_address' finds the starting address
101 of a malloc'd block, given any address within the block. This can be
102 useful for debugging.
104 * There is a new malloc debugging hook `__memalign_hook'.
106 * There are new typedefs `ushort' for `unsigned short int' and `uint' for
107 `unsigned int' in <sys/types.h>. These are for compatibility only and
108 their use is discouraged.
110 * The `-lmcheck' library to enable standard malloc debugging hooks is now
111 done differently, so that it works even without GNU ld.
113 * New function `euidaccess' checks allowed access to a file like `access',
114 but using the effective IDs instead of the real IDs.
116 * The time zone data files have been updated for the latest and greatest
117 local time conventions of the countries of the world.
119 * The new function `dirfd' extracts the file descriptor used by a DIR stream;
122 * The new functions `ecvt', `fcvt', and `gcvt' provide an obsolete interface
123 for formatting floating-point numbers. They are provided only for
124 compatibility; new programs should use `sprintf' instead.
126 * The new auxiliary library `-lutil' from 4.4 BSD contains various
127 functions for maintaining the login-record files (primarily of use to
128 system programs such as `login'), and convenient functions for
129 allocating and initializing a pseudo-terminal (pty) device.
131 * Ulrich Drepper has contributed new support for System V style
132 shared memory and IPC on systems that support it.
134 * Ulrich Drepper has contributed several miscellaneous new functions found
135 in System V: The `hsearch' family of functions provide an effective
136 implementation of hash tables; `a64l' and `l64a' provide a very simple
137 binary to ASCII mapping; `drand48' and friends provide a 48-bit random
140 * Ulrich Drepper has contributed new reentrant counterparts for the
141 `random' and `hsearch' families of functions; `random_r', `hsearch_r', etc.
143 * Ulrich Drepper has contributed new, highly-optimized versions of several
144 string functions for the i486/Pentium family of processors.
146 * Ulrich Drepper has updated the Linux-specific code, based largely
147 on work done in Hongjiu Lu's version of GNU libc for Linux.
148 The GNU library now supports Linux versions 1.3.29 and later,
149 using the ELF object file format (i[345]86-*-linux).
151 * Andreas Schwab has ported the C library to Linux/m68k (m68k-*-linux).
153 * David Mosberger-Tang has ported the C library to Linux/Alpha (alpha-*-linux).
155 * Ulrich Drepper has contributed a new set of message catalog functions to
156 support multiple languages, for use with his new package GNU gettext.
158 * New header file <values.h> gives SVID-compatible names for <limits.h>
161 * Various new macros, declarations, and small header files for compatibility
164 * New function `group_member' is a convenient way to check if a process has
165 a given effective group ID.
167 * When using GCC 2.7 and later, the socket functions are now declared in a
168 special way so that passing an argument of type `struct sockaddr_in *',
169 `struct sockaddr_ns *', or `struct sockaddr_un *' instead of the generic
170 `struct sockaddr *' type, does not generate a type-clash warning.
172 * New function `error' declared in header file <error.h> is a convenient
173 function for printing error messages and optionally exitting; this is the
174 canonical function used in GNU programs. The new functions `err', `warn',
175 and friends in header file <err.h> are the canonical 4.4 BSD interface for
176 doing the same thing.
178 * The <glob.h> interface has several new flags from 4.4 BSD that extend the
179 POSIX.2 `glob' function to do ~ and {...} expansion.
181 * New function `unsetenv' complements `setenv' for compatibility with 4.4 BSD.
183 * New function `getsid' returns session ID number on systems that support it.
185 * We have incorporated the 4.4 BSD `db' library (version 1.85). New header
186 files <db.h> and <mpool.h> provide a rich set of functions for several
187 types of simple databases stored in memory and in files, and <ndbm.h> is
188 an old `ndbm'-compatbile interface using the `db' functions.
190 * New macro `strdupa' copies a string like `strdup', but uses local stack
191 space from `alloca' instead of dynamic heap space from `malloc'.
193 * New function `strnlen' is like `strlen' but searches only a given maximum
194 number of characters for the null terminator.
198 * For cross-compilation you should now set `BUILD_CC' instead of `HOST_CC'.
200 * New header file <fstab.h> and new functions `getfsspec', `getfsent' and
201 friends, for parsing /etc/fstab. This code comes from 4.4 BSD.
203 * The new function `daemon' from 4.4 BSD is useful for server programs that
204 want to put themselves in the background.
206 * Joel Sherrill has contributed support for several standalone boards that
207 run without an operating system.
209 * `printf', `scanf' and friends now accept a `q' type modifier for long
210 long int as well as `ll'. Formats using these might be `%qu' or `%lld'.
212 * All of the code taken from BSD (notably most of the math and networking
213 routines) has been updated from the BSD 4.4-Lite release.
215 * The resolver code has been updated from the BIND-4.9.3-BETA9 release.
217 * The new functions `getdomainname' and `setdomainname' fetch or change the
218 YP/NIS domain name. These are system calls which exist on systems which
221 * The time zone data files have been updated for the latest international
224 * The SunRPC programs `portmap' and `rpcinfo' are now installed in
225 $(sbindir) (usually /usr/local/sbin) instead of $(bindir).
229 * The C library now includes support for Sun RPC, from Sun's free
230 RPCSRC-4.0 distribution. The `portmap', `rpcinfo', and `rpcgen' programs
231 are included. (There is still no support for YP.)
233 * Tom Quinn has contributed a port of the C library to SGI machines running
234 Irix 4 (mips-sgi-irix4).
236 * The new `lockf' function is a simplified interface to the locking
237 facilities of `fcntl', included for compatibility.
239 * New time functions `timegm', `timelocal', and `dysize' for compatibility.
241 * New header file <sys/timeb.h> and new function `ftime' for compatibility.
243 * New header files <poll.h> and <sys/poll.h> and new function `poll' for
246 * The error message printed by `assert' for a failed assertion now includes
247 the name of the program (if using GNU ld) and the name of the calling
248 function (with versions of GCC that support this).
250 * The `psignal' function is now declared in <signal.h>, not <stdio.h>.
252 * The library now includes the <sys/mman.h> header file and memory
253 management functions `mmap', `munmap', `mprotect', `msync', and
254 `madvise', on systems that support those facilities.
256 * The interface for `mcheck' has changed slightly: the function called to
257 abort the program when an allocation inconsistency is detected now takes
258 an argument that indicates the type of failure. The new function
259 `mprobe' lets you request a consistency check for a particular block at
260 any time (checks are normally done only when you call `free' or `realloc'
263 * It is now possible to easily cross-compile the C library, building on one
264 system a library to run on another machine and/or operating system. All
265 you need to do is set the variable `HOST_CC' in `configparms' to the
266 native compiler for programs to run on the machine you are building on (a
267 few generator programs are used on Unix systems); set `CC' to the
270 * The new function `fexecve' (only implemented on the GNU system) executes
271 a program file given a file descriptor already open on the file.
275 * Brendan Kehoe has contributed most of a port to the DEC Alpha
276 running OSF/1 (alpha-dec-osf1). He says it is 75% complete.
278 * You can set the variable `libprefix' in `configparms' to specify a prefix
279 to be prepended to installed library files; this makes it easy to install
280 the GNU C library to be linked as `-lgnuc' or whatever.
282 * The new `stpncpy' is a cross between `stpcpy' and `strncpy': It
283 copies a limited number of characters from a string, and returns the
284 address of the last character written.
286 * You no longer need to check for whether the installed `stddef.h' is
287 compatible with the GNU C library. configure now checks for you.
289 * You can now define a per-stream `fileno' function to convert the
290 stream's cookie into an integral file descriptor.
292 * ``malloc (0)'' no longer returns a null pointer. Instead, it
293 allocates zero bytes of storage, and returns a unique pointer which
294 you can pass to `realloc' or `free'. The behavior is undefined if
295 you dereference this pointer.
297 * The C library now runs on Sony NEWS m68k machines running either
298 NewsOS 3 or NewsOS 4.
300 * The new `syscall' function is a system-dependent primitive function
301 for invoking system calls. It has the canonical behavior on Unix
302 systems, including unreliable return values for some calls (such as
303 `pipe', `fork' and `getppid').
305 * The error code `EWOULDBLOCK' is now obsolete; it is always defined
306 to `EAGAIN', which is the preferred name. On systems whose kernels
307 use two distinct codes, the C library now translates EWOULDBLOCK to
308 EAGAIN in every system call function.
312 * The GNU C Library Reference Manual is now distributed with the library.
313 `make dvi' will produce a DVI file of the printed manual.
314 `make info' will produce Info files that you can read on line using C-h i
315 in Emacs or the `info' program.
316 Please send comments on the manual to bug-glibc-manual@prep.ai.mit.edu.
318 * The library now supports SVR4 on i386s (i386-unknown-sysv4).
320 * Brendan Kehoe has contributed a port to Sun SPARCs running Solaris 2.
322 * Jason Merrill has contributed a port to the Sequent Symmetry running
323 Dynix version 3 (i386-sequent-dynix).
325 * The library has been ported to i386s running SCO 3.2.4 (also known as SCO
326 ODT 2.0; i386-unknown-sco3.2.4) or SCO 3.2 (i386-unknown-sco3.2).
328 * New function `memory_warnings' lets you arrange to get warnings when
329 malloc is running out of memory to allocate, like Emacs gives you.
331 * The C library now contains the relocating allocator used in Emacs 19 for
332 its editing buffers. This allocator (ralloc) minimizes allocation
333 overhead and fragmentation by moving allocated regions around whenever it
334 needs to. You always refer to a ralloc'd region with a "handle" (a
335 pointer to a pointer--an object of type `void **').
337 * There is a new `printf' format: `%m' gives you the string corresponding
338 to the error code in `errno'.
340 * In `scanf' formats, you can now use `%as' or `%a[' to do the normal `%s'
341 or `%[' conversion, but instead of filling in a fixed-sized buffer you
342 pass, the `a' modifier says to fill in a `char **' you pass with a
345 * The `fnmatch' function supports the new flag bits `FNM_LEADING_DIR' and
346 `FNM_CASEFOLD'. `FNM_LEADING_DIR' lets a pattern like `foo*' match a
347 name like `foo/bar'. `FNM_CASEFOLD' says to ignore case in matching.
349 * `mkstemp' is a traditional Unix function to atomically create and open a
350 uniquely-named temporary file.
354 * The standard location for the file that says what the local timezone is
355 has changed again. It is now `/usr/local/etc/localtime' (or more
356 precisely, `${prefix}/etc/localtime') rather than `/etc/localtime'.
358 * The distribution no longer contains any files with names longer than 14
361 * `struct ttyent' has two new flag bits: TTY_TRUSTED and TTY_CONSOLE.
362 These are set by the new `trusted' and `console' keywords in `/etc/ttys'.
364 * New functions `ttyslot' and `syslog' from 4.4 BSD.
368 * The configuration process has changed quite a bit. The `configure'
369 script is now used just like the configuration scripts for other GNU
370 packages. The `sysdeps' directory hierarchy is much rearranged.
371 The file `INSTALL' explains the new scheme in detail.
373 * The header files no longer need to be processed into ANSI C and
374 traditional C versions. There is just one set of files to install, and
375 it will work with ANSI or old C compilers (including `gcc -traditional').
377 * Brendan Kehoe and Ian Lance Taylor have ported the library to the
378 MIPS DECStation running Ultrix 4.
380 * The Sun 4 startup code (crt0) can now properly load SunOS 4 shared libraries.
381 Tom Quinn contributed the initial code. The GNU C library can NOT yet be
382 made itself into a shared library.
384 * Yet further improved support for the i386, running 4.3 BSD-like systems
385 (such as Mach 3 with the Unix single-server), or System V.
387 * New function `strncasecmp' to do case-insensitive string comparison
390 * New function `strsep' is a reentrant alternative to `strtok'.
392 * New functions `scandir' and `alphasort' for searching directories.
394 * New function `setenv' is a better interface to `putenv'.
396 * Ian Lance Taylor has contributed an implementation of the SVID `ftw'
397 function for traversing a directory tree.
399 * The GNU obstack package is now also part of the C library.
400 The new function `open_obstack_stream' creates a stdio stream that
401 writes onto an obstack; `obstack_printf' and `obstack_vprintf' do
402 formatted output directly to an obstack.
404 * Miscellaneous new functions: reboot, nice, sigaltstack (4.4 BSD only),
405 cfmakeraw, getusershell, getpass, swab, getttyent, seteuid, setegid.
407 * `FNM_FILE_NAME' is another name for `FNM_PATHNAME', used with `fnmatch'.
409 * The new functions `strfry' and `memfrob' do mysterious and wonderful
410 things to your strings.
412 * There are some new test programs: test-fseek, testmb, and testrand.
414 * Some work has been done to begin porting the library to 4.4 BSD and Linux.
415 These ports are not finished, but are a good starting place for really
416 supporting those systems.
418 * `/etc/localtime' is now the standard location for the file that says what
419 the local timezone is, rather than `/usr/local/lib/zoneinfo/localtime'.
420 This follows the general principle that `/etc' is the place for all local
423 * The C library header files now use `extern "C"' when used by the C++
424 compiler, so the C library should now work with C++ code.
426 * The header file <bstring.h> is gone. <string.h> now declares bcopy,
427 bcmp, bzero, and ffs.
429 * Mike Haertel (of GNU e?grep and malloc fame) has written a new sorting
430 function which uses the `merge sort' algorithm, and is said to be
431 significantly faster than the old GNU `qsort' function. Merge sort is
432 now the standard `qsort' function. The new algorithm can require a lot
433 of temporary storage; so, the old sorting function is called when the
434 required storage is not available.
436 * The C library now includes Michael Glad's Ultra Fast Crypt, which
437 provides the Unix `crypt' function, plus some other entry points.
438 Because of the United States export restriction on DES implementations,
439 we are distributing this code separately from the rest of the C library.
440 There is an extra distribution tar file just for crypt; it is called
441 `glibc-VERSION-crypt.tar.Z', e.g. `glibc-1.04-crypt.tar.Z'. You can just
442 unpack the crypt distribution along with the rest of the C library and
443 build; you can also build the library without getting crypt. Users
444 outside the USA can get the crypt distribution via anonymous FTP from
445 ftp.uni-c.dk [129.142.6.74], or another archive site outside the U.S.
447 * The code and header files taken from 4.4 BSD have been updated with the
448 latest files released from Berkeley.
450 ----------------------------------------------------------------------
451 Copyright information:
453 Copyright (C) 1992, 93, 94, 95, 96 Free Software Foundation, Inc.
455 Permission is granted to anyone to make or distribute verbatim copies
456 of this document as received, in any medium, provided that the
457 copyright notice and this permission notice are preserved,
458 thus giving the recipient permission to redistribute in turn.
460 Permission is granted to distribute modified versions
461 of this document, or of portions of it,
462 under the above conditions, provided also that they
463 carry prominent notices stating who last changed them.
466 version-control: never