1 GNU C Library NEWS -- history of user-visible changes. 1998-03-04
3 Copyright (C) 1992, 93, 94, 95, 96, 97, 98 Free Software Foundation, Inc.
4 See the end for copying conditions.
6 Please send GNU C library bug reports using the `glibcbug' script to
7 <bugs@gnu.org>. Questions and suggestions should be send to
22 * inet_ntoa is thread-safe
24 * updwtmp is moved from libutil to libc
26 * rewrite of cbrt function
28 * update of timezone data
44 * fix complex problems in Berkeley DB code
50 * fixed lots of header problems (especially Linux/GNU specific)
52 * dynamic loader preserves all registers
54 * Roland McGrath provided support for handling of auxiliary objects in
55 the ELF dynamic loader.
57 * support for parallel builds is improved
61 * GNU extensions are no longer declared by default. To enable them you
62 must define the macro `_GNU_SOURCE' in your program or compile with
65 * The library has changed from using GNU ld symbol aliases to using weak
66 symbols where available. The ELF object file format supports weak
67 symbols; GNU ld also supports weak symbols in the a.out format. (There
68 is also now support for other GNU ld extensions in ELF. Use the
69 `--with-elf' option to configure to indicate you have ELF, and
70 `--with-gnu-ld' if using GNU ld.) This change resulted in the deletion
71 of many files which contained only symbol aliases, reducing the size of
72 the source and the compiled library; many other files were renamed to
73 less cryptic names previously occupied by the symbol alias files.
74 There is a new header file <elf.h> for programs which operate on
75 files in the ELF format.
77 * Converted to Autoconf version 2, so `configure' has more options.
78 Run `configure --help' to see the details.
80 * The library can now be configured to build profiling, highly-optimized
81 (but undebuggable), and/or shared libraries (ELF with GNU ld only). The
82 `--enable-profile', `--enable-omitfp', and `--enable-shared' options to
83 `configure' enable building these extra libraries. The shared library is
84 built by default when using both ELF and GNU ld. When shared libraries
85 are enabled, the new library `-ldl' is available for arbitrary run-time
86 loading of shared objects; its interface is defined in <dlfcn.h>. The
87 new header file <link.h> gives access to the internals of the run-time
88 dynamic linker, `ld.so'. The shell script `ldd' is similar to the
89 application of same name on other systems and it provides information
90 about dynamically linked binaries.
92 * The C library now provides the run-time support code for profiling
93 executables compiled with `-pg'. Programs can control the profiling code
94 through the interface in <sys/gmon.h>. The `gmon.out' files written by
95 the GNU C library can be read only by GNU `gprof' (from GNU binutils);
96 the support for this file format was contributed by David Mosberger-Tang.
98 * The math code has been replaced with a math library based on fdlibm from
99 Sun, and modified by JT Conklin and Ulrich Drepper with i387 support, by
100 Ian Taylor with `float' functions and by Ulrich Drepper with `long double'
101 functions. The math functions now reside in a separate library, so
102 programs using them will need to use `-lm' their linking commands.
104 * John C. Bowman contributed optimized ix87 assembler inline functions.
106 * Ulrich Drepper has contributed support for an `/etc/nsswitch.conf'
107 mechanism similar to that found in Solaris 2. This is now used for the
108 group, passwd, hosts, networks, services, protocols, rpc, ethers,
109 shadow, netgroup, publickey, and alias databases. The `nsswitch.conf'
110 file controls what services are used for each individual database. This
111 works by loading shared libraries with names specified in `nsswitch.conf',
112 so service modules can be changed or added at any time without even
113 relinking any program. Currently there are the file, db, and NIS based
114 NSS services available.
116 * The new functions `strtoq' and `strtouq' parse integer values from
117 strings, like `strtol' and `strtoul', but they return `long long int' and
118 `unsigned long long int' values, respectively (64-bit quantities).
120 * The new functions `strtof' and `strtold' parse floating-point values from
121 strings, like `strtod', but they return `float' and `long double' values,
122 respectively (on some machines `double' and `long double' are the same).
124 * Ulrich Drepper has contributed new implementations of the floating-point
125 printing and reading code used in the `printf' family of functions and
126 `strtod', `strtof', and `strtold'. These new functions are perfectly
127 accurate, and much faster than the old ones.
129 * The implementation of the POSIX locale model was completely rewritten by
130 Ulrich Drepper. This includes the new programs `localedef' and `locale'
131 to compile the POSIX locale definition.
133 * The former dummy implementations of the strcoll and strxfrm function are
134 now replaced by fully functional code contributed by Ulrich Drepper. The
135 collation information comes from the POSIX locale definitions.
137 * The new header <langinfo.h> defines an interface for accessing
138 various locale-dependent data (using the locale chosen with `setlocale').
140 * Ulrich Drepper has contributed a new suite of functions for operation on
141 wide-character and multibyte-character strings, in <wchar.h>;
142 and classification and case conversion of wide characters, in <wctype.h>.
143 These new functions are conforming to the ISO C, Amendement 1 specification.
145 * There is now a second implementation of the standard I/O library available.
146 It comes from GNU libg++ as was written by Per Bothner, heavily modified
147 by Hongjiu Lu and made thread safe by Ulrich Drepper.
149 * You can now use positional parameter specifications in format strings
150 for the `printf' and `scanf' families of functions. For example,
151 `printf ("Number %2$d, Mr %1$s\n", "Jones", 6);'' prints
152 ``Number 6, Mr Jones''. This is mainly useful when providing different
153 format strings for different languages, whose grammars may dictate
154 different orderings of the values being printed. To support this
155 feature, the interface for `register_printf_handler' has changed; see
156 the header file <printf.h> for details.
158 * The `printf' and `scanf' families of functions now understand a new
159 formatting flag for numeric conversions: the ' flag (e.g. %'d or %'f) says
160 to group numbers as indicated by the locale; for `scanf' and friends, this
161 says to accept as valid only a number with all the proper grouping
162 separators in the right places. In the default "C" locale, numbers are
163 not grouped; but locales for specific countries will define the usual
164 conventions (i.e. separate thousands with `,' in the US locale).
166 * The pgrp functions have been regularized, slightly incompatibly but much
167 less confusingly. The core functions are now `getpgid' and `setpgid',
168 which take arguments for the PID to operate on; the POSIX.1 `getpgrp' (no
169 argument) and BSD `setpgrp' (identical to `setpgid') functions are
170 provided for compatibility. There is no longer an incompatible `getpgrp'
171 with an argument declared under _BSD_SOURCE; no BSD code uses it.
173 * The new header file <fts.h> and suite of functions simplify programs that
174 operate on directory trees. This code comes from 4.4 BSD.
176 * The resolver code has been updated from the BIND 4.9.5-P1 release.
177 Parts of the code were heavily modified by Ulrich Drepper to fit in the
178 NSS scheme used in glibc.
180 * The new function `malloc_find_object_address' finds the starting address
181 of a malloc'd block, given any address within the block;
182 `malloc_object_allocated_size' returns the size of an allocated block;
183 and `malloc_walk' lets you walk through all allocated blocks. These can
184 be useful for debugging; see <malloc.h> for the interfaces.
186 * There is a new malloc debugging hook `__memalign_hook'.
188 * There are new typedefs `ushort' for `unsigned short int' and `uint' for
189 `unsigned int' in <sys/types.h>. These are for compatibility only and
190 their use is discouraged.
192 * The `-lmcheck' library to enable standard malloc debugging hooks is now
193 done differently, so that it works even without GNU ld.
195 * New function `euidaccess' checks allowed access to a file like `access',
196 but using the effective IDs instead of the real IDs.
198 * The time zone data files have been updated for the latest and greatest
199 local time conventions of the countries of the world.
201 * The new function `dirfd' extracts the file descriptor used by a DIR stream;
204 * The new functions `ecvt', `fcvt', and `gcvt' provide an obsolete interface
205 for formatting floating-point numbers. They are provided only for
206 compatibility; new programs should use `sprintf' instead. There are
207 also equivalent function for the `long double' floating-point type and
208 all functions also exist in a reentrant form.
210 * The new auxiliary library `-lutil' from 4.4 BSD contains various
211 functions for maintaining the login-record files (primarily of use to
212 system programs such as `login'), and convenient functions for
213 allocating and initializing a pseudo-terminal (pty) device.
215 * Ulrich Drepper has contributed new support for System V style
216 shared memory and IPC on systems that support it.
218 * Ulrich Drepper has contributed several miscellaneous new functions found
219 in System V: The `hsearch' family of functions provide an effective
220 implementation of hash tables; `a64l' and `l64a' provide a very simple
221 binary to ASCII mapping; `drand48' and friends provide a 48-bit random
224 * Ulrich Drepper has contributed new reentrant counterparts for the
225 `random' and `hsearch' families of functions; `random_r', `hsearch_r', etc.
227 * Ulrich Drepper has contributed new, highly-optimized versions of several
228 string functions for the i486/Pentium family of processors.
230 * Ulrich Drepper has updated the Linux-specific code, based largely
231 on work done in Hongjiu Lu's version of GNU libc for Linux.
232 The GNU library now supports Linux versions 2.0.10 and later,
233 using the ELF object file format (i[3456]86-*-linux).
235 * Andreas Schwab has ported the C library to Linux/m68k (m68k-*-linux).
237 * David Mosberger-Tang and Richard Henderson have ported the C library
238 to Linux/Alpha (alpha-*-linux). Richard Henderson contributed the
239 dynamic linking support for ELF/Alpha.
241 * Richard Henderson contributed several Alpha optimized assembler function
242 for arithmetic and string handling.
244 * Ulrich Drepper has contributed a new set of message catalog functions to
245 support multiple languages using the <libintl.h> interface, for use with
246 his new package GNU gettext. Translation volunteers have contributed
247 catalogs of the library's messages in Spanish, German, and Korean.
249 * For compatibility with XPG4, Ulrich Drepper has contributed the `gencat'
250 program and the `catgets' function for reading the catalog files it
251 creates. (The <libintl.h> interface is preferred; we include the
252 <nl_types.h> interface using `catgets' only for source compatibility with
253 programs already written to use it.)
255 * New header file <values.h> gives SVID-compatible names for <limits.h>
258 * Various new macros, declarations, and small header files for compatibility
261 * New function `group_member' is a convenient way to check if a process has
262 a given effective group ID.
264 * When using GCC 2.7 and later, the socket functions are now declared in a
265 special way so that passing an argument of type `struct sockaddr_in *',
266 `struct sockaddr_ns *', or `struct sockaddr_un *' instead of the generic
267 `struct sockaddr *' type, does not generate a type-clash warning.
269 * New function `error' declared in header file <error.h> is a convenient
270 function for printing error messages and optionally exiting; this is the
271 canonical function used in GNU programs. The new functions `err', `warn',
272 and friends in header file <err.h> are the canonical 4.4 BSD interface for
273 doing the same thing.
275 * The <glob.h> interface has several new flags from 4.4 BSD that extend the
276 POSIX.2 `glob' function to do ~ and {...} expansion.
278 * New function `unsetenv' complements `setenv' for compatibility with 4.4 BSD.
279 `clearenv' which is used in POSIX.9 is also available.
281 * New function `getsid' returns session ID number on systems that support it.
283 * We have incorporated the 4.4 BSD `db' library (version 1.85). New header
284 files <db.h> and <mpool.h> provide a rich set of functions for several
285 types of simple databases stored in memory and in files, and <ndbm.h> is
286 an old `ndbm'-compatible interface using the `db' functions. Link with
287 `-ldb' to get these functions.
289 * New macro `strdupa' copies a string like `strdup', but uses local stack
290 space from `alloca' instead of dynamic heap space from `malloc'.
292 * New function `strnlen' is like `strlen' but searches only a given maximum
293 number of characters for the null terminator. `stpncpy', `strndup' and
294 `strndupa' are similar variants for the `stpcpy', `strdup' and `strdupa'
297 * New function `statfs' in header <sys/statfs.h>.
299 * The new <argz.h> and <envz.h> interfaces contributed by Miles Bader
300 provide convenient functions for operating on blocks of null-terminated
303 * A new suite of functions in <utmp.h> handle all the details of reading
304 and writing the utmp file.
306 * An implementation of the NIS/YP(tm) based NSS service was contributed by
309 * Paul Eggert and Ulrich Drepper modified the `strftime' function to be
310 completely POSIX compliant and also implemented the extended functionality
311 to handle alternate digit representation and alternate era date formats.
313 * Ulrich Drepper provided an implementation of the `strptime' function
314 defined in XPG4.2 which transforms a string into a `struct tm' value.
316 * Paul Eggert provided the tzselect shell script as part of the timezone
317 code. The shell script makes it easy to select the correct timezone
320 * The implementation of the malloc family of functions is completely replaced
321 by a new implementation by Doug Lea with many improvements by Wolfram Gloger.
322 The implementation uses the mmap function (if available) and it is
323 optimized for the use in multi threaded programs.
325 * Ulrich Drepper contributed a MD5 "encryption" for the crypt family of
326 functions. This new functionality is usable by specifying a special
327 salt string and it is compatible with implementation on *BSD systems.
329 * Lots of functions from the XPG4.2 standard were added by Ulrich Drepper:
330 `getsubopt' to handle second level command line options, `bsd_signal'
331 to access BSD style `signal' functionality, the obsolete `regexp' style
334 * the `lchown' function is available on system which support this
337 * The implementation of the shadow password handling function was contributed
340 * David Mosberger-Tang changed the SunRPC implementation to be 64bit safe.
342 * POSIX.1g support was added. The <sys/select.h> header is available,
343 `isfdtype' and `pselect' are implemented. Craig Metz contributed an
344 implementation of `getaddrinfo'.
348 * For cross-compilation you should now set `BUILD_CC' instead of `HOST_CC'.
350 * New header file <fstab.h> and new functions `getfsspec', `getfsent' and
351 friends, for parsing /etc/fstab. This code comes from 4.4 BSD.
353 * The new function `daemon' from 4.4 BSD is useful for server programs that
354 want to put themselves in the background.
356 * Joel Sherrill has contributed support for several standalone boards that
357 run without an operating system.
359 * `printf', `scanf' and friends now accept a `q' type modifier for long
360 long int as well as `ll'. Formats using these might be `%qu' or `%lld'.
362 * All of the code taken from BSD (notably most of the math and networking
363 routines) has been updated from the BSD 4.4-Lite release.
365 * The resolver code has been updated from the BIND-4.9.3-BETA9 release.
367 * The new functions `getdomainname' and `setdomainname' fetch or change the
368 YP/NIS domain name. These are system calls which exist on systems which
371 * The time zone data files have been updated for the latest international
374 * The SunRPC programs `portmap' and `rpcinfo' are now installed in
375 $(sbindir) (usually /usr/local/sbin) instead of $(bindir).
379 * The C library now includes support for Sun RPC, from Sun's free
380 RPCSRC-4.0 distribution. The `portmap', `rpcinfo', and `rpcgen' programs
381 are included. (There is still no support for YP.)
383 * Tom Quinn has contributed a port of the C library to SGI machines running
384 Irix 4 (mips-sgi-irix4).
386 * The new `lockf' function is a simplified interface to the locking
387 facilities of `fcntl', included for compatibility.
389 * New time functions `timegm', `timelocal', and `dysize' for compatibility.
391 * New header file <sys/timeb.h> and new function `ftime' for compatibility.
393 * New header files <poll.h> and <sys/poll.h> and new function `poll' for
396 * The error message printed by `assert' for a failed assertion now includes
397 the name of the program (if using GNU ld) and the name of the calling
398 function (with versions of GCC that support this).
400 * The `psignal' function is now declared in <signal.h>, not <stdio.h>.
402 * The library now includes the <sys/mman.h> header file and memory
403 management functions `mmap', `munmap', `mprotect', `msync', and
404 `madvise', on systems that support those facilities.
406 * The interface for `mcheck' has changed slightly: the function called to
407 abort the program when an allocation inconsistency is detected now takes
408 an argument that indicates the type of failure. The new function
409 `mprobe' lets you request a consistency check for a particular block at
410 any time (checks are normally done only when you call `free' or `realloc'
413 * It is now possible to easily cross-compile the C library, building on one
414 system a library to run on another machine and/or operating system. All
415 you need to do is set the variable `HOST_CC' in `configparms' to the
416 native compiler for programs to run on the machine you are building on (a
417 few generator programs are used on Unix systems); set `CC' to the
420 * The new function `fexecve' (only implemented on the GNU system) executes
421 a program file given a file descriptor already open on the file.
425 * Brendan Kehoe has contributed most of a port to the DEC Alpha
426 running OSF/1 (alpha-dec-osf1). He says it is 75% complete.
428 * You can set the variable `libprefix' in `configparms' to specify a prefix
429 to be prepended to installed library files; this makes it easy to install
430 the GNU C library to be linked as `-lgnuc' or whatever.
432 * The new `stpncpy' is a cross between `stpcpy' and `strncpy': It
433 copies a limited number of characters from a string, and returns the
434 address of the last character written.
436 * You no longer need to check for whether the installed `stddef.h' is
437 compatible with the GNU C library. configure now checks for you.
439 * You can now define a per-stream `fileno' function to convert the
440 stream's cookie into an integral file descriptor.
442 * ``malloc (0)'' no longer returns a null pointer. Instead, it
443 allocates zero bytes of storage, and returns a unique pointer which
444 you can pass to `realloc' or `free'. The behavior is undefined if
445 you dereference this pointer.
447 * The C library now runs on Sony NEWS m68k machines running either
448 NewsOS 3 or NewsOS 4.
450 * The new `syscall' function is a system-dependent primitive function
451 for invoking system calls. It has the canonical behavior on Unix
452 systems, including unreliable return values for some calls (such as
453 `pipe', `fork' and `getppid').
455 * The error code `EWOULDBLOCK' is now obsolete; it is always defined
456 to `EAGAIN', which is the preferred name. On systems whose kernels
457 use two distinct codes, the C library now translates EWOULDBLOCK to
458 EAGAIN in every system call function.
462 * The GNU C Library Reference Manual is now distributed with the library.
463 `make dvi' will produce a DVI file of the printed manual.
464 `make info' will produce Info files that you can read on line using C-h i
465 in Emacs or the `info' program.
466 Please send comments on the manual to bug-glibc-manual@gnu.org.
468 * The library now supports SVR4 on i386s (i386-unknown-sysv4).
470 * Brendan Kehoe has contributed a port to Sun SPARCs running Solaris 2.
472 * Jason Merrill has contributed a port to the Sequent Symmetry running
473 Dynix version 3 (i386-sequent-dynix).
475 * The library has been ported to i386s running SCO 3.2.4 (also known as SCO
476 ODT 2.0; i386-unknown-sco3.2.4) or SCO 3.2 (i386-unknown-sco3.2).
478 * New function `memory_warnings' lets you arrange to get warnings when
479 malloc is running out of memory to allocate, like Emacs gives you.
481 * The C library now contains the relocating allocator used in Emacs 19 for
482 its editing buffers. This allocator (ralloc) minimizes allocation
483 overhead and fragmentation by moving allocated regions around whenever it
484 needs to. You always refer to a ralloc'd region with a "handle" (a
485 pointer to a pointer--an object of type `void **').
487 * There is a new `printf' format: `%m' gives you the string corresponding
488 to the error code in `errno'.
490 * In `scanf' formats, you can now use `%as' or `%a[' to do the normal `%s'
491 or `%[' conversion, but instead of filling in a fixed-sized buffer you
492 pass, the `a' modifier says to fill in a `char **' you pass with a
495 * The `fnmatch' function supports the new flag bits `FNM_LEADING_DIR' and
496 `FNM_CASEFOLD'. `FNM_LEADING_DIR' lets a pattern like `foo*' match a
497 name like `foo/bar'. `FNM_CASEFOLD' says to ignore case in matching.
499 * `mkstemp' is a traditional Unix function to atomically create and open a
500 uniquely-named temporary file.
504 * The standard location for the file that says what the local timezone is
505 has changed again. It is now `/usr/local/etc/localtime' (or more
506 precisely, `${prefix}/etc/localtime') rather than `/etc/localtime'.
508 * The distribution no longer contains any files with names longer than 14
511 * `struct ttyent' has two new flag bits: TTY_TRUSTED and TTY_CONSOLE.
512 These are set by the new `trusted' and `console' keywords in `/etc/ttys'.
514 * New functions `ttyslot' and `syslog' from 4.4 BSD.
518 * The configuration process has changed quite a bit. The `configure'
519 script is now used just like the configuration scripts for other GNU
520 packages. The `sysdeps' directory hierarchy is much rearranged.
521 The file `INSTALL' explains the new scheme in detail.
523 * The header files no longer need to be processed into ANSI C and
524 traditional C versions. There is just one set of files to install, and
525 it will work with ANSI or old C compilers (including `gcc -traditional').
527 * Brendan Kehoe and Ian Lance Taylor have ported the library to the
528 MIPS DECStation running Ultrix 4.
530 * The Sun 4 startup code (crt0) can now properly load SunOS 4 shared libraries.
531 Tom Quinn contributed the initial code. The GNU C library can NOT yet be
532 made itself into a shared library.
534 * Yet further improved support for the i386, running 4.3 BSD-like systems
535 (such as Mach 3 with the Unix single-server), or System V.
537 * New function `strncasecmp' to do case-insensitive string comparison
540 * New function `strsep' is a reentrant alternative to `strtok'.
542 * New functions `scandir' and `alphasort' for searching directories.
544 * New function `setenv' is a better interface to `putenv'.
546 * Ian Lance Taylor has contributed an implementation of the SVID `ftw'
547 function for traversing a directory tree.
549 * The GNU obstack package is now also part of the C library.
550 The new function `open_obstack_stream' creates a stdio stream that
551 writes onto an obstack; `obstack_printf' and `obstack_vprintf' do
552 formatted output directly to an obstack.
554 * Miscellaneous new functions: reboot, nice, sigaltstack (4.4 BSD only),
555 cfmakeraw, getusershell, getpass, swab, getttyent, seteuid, setegid.
557 * `FNM_FILE_NAME' is another name for `FNM_PATHNAME', used with `fnmatch'.
559 * The new functions `strfry' and `memfrob' do mysterious and wonderful
560 things to your strings.
562 * There are some new test programs: test-fseek, testmb, and testrand.
564 * Some work has been done to begin porting the library to 4.4 BSD and Linux.
565 These ports are not finished, but are a good starting place for really
566 supporting those systems.
568 * `/etc/localtime' is now the standard location for the file that says what
569 the local timezone is, rather than `/usr/local/lib/zoneinfo/localtime'.
570 This follows the general principle that `/etc' is the place for all local
573 * The C library header files now use `extern "C"' when used by the C++
574 compiler, so the C library should now work with C++ code.
576 * The header file <bstring.h> is gone. <string.h> now declares bcopy,
577 bcmp, bzero, and ffs.
579 * Mike Haertel (of GNU e?grep and malloc fame) has written a new sorting
580 function which uses the `merge sort' algorithm, and is said to be
581 significantly faster than the old GNU `qsort' function. Merge sort is
582 now the standard `qsort' function. The new algorithm can require a lot
583 of temporary storage; so, the old sorting function is called when the
584 required storage is not available.
586 * The C library now includes Michael Glad's Ultra Fast Crypt, which
587 provides the Unix `crypt' function, plus some other entry points.
588 Because of the United States export restriction on DES implementations,
589 we are distributing this code separately from the rest of the C library.
590 There is an extra distribution tar file just for crypt; it is called
591 `glibc-VERSION-crypt.tar.Z', e.g. `glibc-1.04-crypt.tar.Z'. You can just
592 unpack the crypt distribution along with the rest of the C library and
593 build; you can also build the library without getting crypt. Users
594 outside the USA can get the crypt distribution via anonymous FTP from
595 ftp.uni-c.dk [129.142.6.74], or another archive site outside the U.S.
597 * The code and header files taken from 4.4 BSD have been updated with the
598 latest files released from Berkeley.
600 ----------------------------------------------------------------------
601 Copyright information:
603 Copyright (C) 1992, 93, 94, 95, 96 Free Software Foundation, Inc.
605 Permission is granted to anyone to make or distribute verbatim copies
606 of this document as received, in any medium, provided that the
607 copyright notice and this permission notice are preserved,
608 thus giving the recipient permission to redistribute in turn.
610 Permission is granted to distribute modified versions
611 of this document, or of portions of it,
612 under the above conditions, provided also that they
613 carry prominent notices stating who last changed them.
616 version-control: never