1 GNU C Library NEWS -- history of user-visible changes. 1997-11-15
3 Copyright (C) 1992, 93, 94, 95, 96, 97 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
8 <bug-glibc@prep.ai.mit.edu>.
18 * inet_ntoa is thread-safe
20 * updwtmp is moved from libutil to libc
22 * rewrite of cbrt function
24 * update of timezone data
40 * fix complex problems in Berkeley DB code
46 * fixed lots of header problems (especially Linux/GNU specific)
48 * dynamic loader preserves all registers
50 * Roland McGrath provided support for handling of auxiliary objects in
51 the ELF dynamic loader.
53 * support for parallel builds is improved
57 * GNU extensions are no longer declared by default. To enable them you
58 must define the macro `_GNU_SOURCE' in your program or compile with
61 * The library has changed from using GNU ld symbol aliases to using weak
62 symbols where available. The ELF object file format supports weak
63 symbols; GNU ld also supports weak symbols in the a.out format. (There
64 is also now support for other GNU ld extensions in ELF. Use the
65 `--with-elf' option to configure to indicate you have ELF, and
66 `--with-gnu-ld' if using GNU ld.) This change resulted in the deletion
67 of many files which contained only symbol aliases, reducing the size of
68 the source and the compiled library; many other files were renamed to
69 less cryptic names previously occupied by the symbol alias files.
70 There is a new header file <elf.h> for programs which operate on
71 files in the ELF format.
73 * Converted to Autoconf version 2, so `configure' has more options.
74 Run `configure --help' to see the details.
76 * The library can now be configured to build profiling, highly-optimized
77 (but undebuggable), and/or shared libraries (ELF with GNU ld only). The
78 `--enable-profile', `--enable-omitfp', and `--enable-shared' options to
79 `configure' enable building these extra libraries. The shared library is
80 built by default when using both ELF and GNU ld. When shared libraries
81 are enabled, the new library `-ldl' is available for arbitrary run-time
82 loading of shared objects; its interface is defined in <dlfcn.h>. The
83 new header file <link.h> gives access to the internals of the run-time
84 dynamic linker, `ld.so'. The shell script `ldd' is similar to the
85 application of same name on other systems and it provides information
86 about dynamically linked binaries.
88 * The C library now provides the run-time support code for profiling
89 executables compiled with `-pg'. Programs can control the profiling code
90 through the interface in <sys/gmon.h>. The `gmon.out' files written by
91 the GNU C library can be read only by GNU `gprof' (from GNU binutils);
92 the support for this file format was contributed by David Mosberger-Tang.
94 * The math code has been replaced with a math library based on fdlibm from
95 Sun, and modified by JT Conklin and Ulrich Drepper with i387 support, by
96 Ian Taylor with `float' functions and by Ulrich Drepper with `long double'
97 functions. The math functions now reside in a separate library, so
98 programs using them will need to use `-lm' their linking commands.
100 * John C. Bowman contributed optimized ix87 assembler inline functions.
102 * Ulrich Drepper has contributed support for an `/etc/nsswitch.conf'
103 mechanism similar to that found in Solaris 2. This is now used for the
104 group, passwd, hosts, networks, services, protocols, rpc, ethers,
105 shadow, netgroup, publickey, and alias databases. The `nsswitch.conf'
106 file controls what services are used for each individual database. This
107 works by loading shared libraries with names specified in `nsswitch.conf',
108 so service modules can be changed or added at any time without even
109 relinking any program. Currently there are the file, db, and NIS based
110 NSS services available.
112 * The new functions `strtoq' and `strtouq' parse integer values from
113 strings, like `strtol' and `strtoul', but they return `long long int' and
114 `unsigned long long int' values, respectively (64-bit quantities).
116 * The new functions `strtof' and `strtold' parse floating-point values from
117 strings, like `strtod', but they return `float' and `long double' values,
118 respectively (on some machines `double' and `long double' are the same).
120 * Ulrich Drepper has contributed new implementations of the floating-point
121 printing and reading code used in the `printf' family of functions and
122 `strtod', `strtof', and `strtold'. These new functions are perfectly
123 accurate, and much faster than the old ones.
125 * The implementation of the POSIX locale model was completely rewritten by
126 Ulrich Drepper. This includes the new programs `localedef' and `locale'
127 to compile the POSIX locale definition.
129 * The former dummy implementations of the strcoll and strxfrm function are
130 now replaced by fully functional code contributed by Ulrich Drepper. The
131 collation information comes from the POSIX locale definitions.
133 * The new header <langinfo.h> defines an interface for accessing
134 various locale-dependent data (using the locale chosen with `setlocale').
136 * Ulrich Drepper has contributed a new suite of functions for operation on
137 wide-character and multibyte-character strings, in <wchar.h>;
138 and classification and case conversion of wide characters, in <wctype.h>.
139 These new functions are conforming to the ISO C, Amendement 1 specification.
141 * There is now a second implementation of the standard I/O library available.
142 It comes from GNU libg++ as was written by Per Bothner, heavily modified
143 by Hongjiu Lu and made thread safe by Ulrich Drepper.
145 * You can now use positional parameter specifications in format strings
146 for the `printf' and `scanf' families of functions. For example,
147 `printf ("Number %2$d, Mr %1$s\n", "Jones", 6);'' prints
148 ``Number 6, Mr Jones''. This is mainly useful when providing different
149 format strings for different languages, whose grammars may dictate
150 different orderings of the values being printed. To support this
151 feature, the interface for `register_printf_handler' has changed; see
152 the header file <printf.h> for details.
154 * The `printf' and `scanf' families of functions now understand a new
155 formatting flag for numeric conversions: the ' flag (e.g. %'d or %'f) says
156 to group numbers as indicated by the locale; for `scanf' and friends, this
157 says to accept as valid only a number with all the proper grouping
158 separators in the right places. In the default "C" locale, numbers are
159 not grouped; but locales for specific countries will define the usual
160 conventions (i.e. separate thousands with `,' in the US locale).
162 * The pgrp functions have been regularized, slightly incompatibly but much
163 less confusingly. The core functions are now `getpgid' and `setpgid',
164 which take arguments for the PID to operate on; the POSIX.1 `getpgrp' (no
165 argument) and BSD `setpgrp' (identical to `setpgid') functions are
166 provided for compatibility. There is no longer an incompatible `getpgrp'
167 with an argument declared under _BSD_SOURCE; no BSD code uses it.
169 * The new header file <fts.h> and suite of functions simplify programs that
170 operate on directory trees. This code comes from 4.4 BSD.
172 * The resolver code has been updated from the BIND 4.9.5-P1 release.
173 Parts of the code were heavily modified by Ulrich Drepper to fit in the
174 NSS scheme used in glibc.
176 * The new function `malloc_find_object_address' finds the starting address
177 of a malloc'd block, given any address within the block;
178 `malloc_object_allocated_size' returns the size of an allocated block;
179 and `malloc_walk' lets you walk through all allocated blocks. These can
180 be useful for debugging; see <malloc.h> for the interfaces.
182 * There is a new malloc debugging hook `__memalign_hook'.
184 * There are new typedefs `ushort' for `unsigned short int' and `uint' for
185 `unsigned int' in <sys/types.h>. These are for compatibility only and
186 their use is discouraged.
188 * The `-lmcheck' library to enable standard malloc debugging hooks is now
189 done differently, so that it works even without GNU ld.
191 * New function `euidaccess' checks allowed access to a file like `access',
192 but using the effective IDs instead of the real IDs.
194 * The time zone data files have been updated for the latest and greatest
195 local time conventions of the countries of the world.
197 * The new function `dirfd' extracts the file descriptor used by a DIR stream;
200 * The new functions `ecvt', `fcvt', and `gcvt' provide an obsolete interface
201 for formatting floating-point numbers. They are provided only for
202 compatibility; new programs should use `sprintf' instead. There are
203 also equivalent function for the `long double' floating-point type and
204 all functions also exist in a reentrant form.
206 * The new auxiliary library `-lutil' from 4.4 BSD contains various
207 functions for maintaining the login-record files (primarily of use to
208 system programs such as `login'), and convenient functions for
209 allocating and initializing a pseudo-terminal (pty) device.
211 * Ulrich Drepper has contributed new support for System V style
212 shared memory and IPC on systems that support it.
214 * Ulrich Drepper has contributed several miscellaneous new functions found
215 in System V: The `hsearch' family of functions provide an effective
216 implementation of hash tables; `a64l' and `l64a' provide a very simple
217 binary to ASCII mapping; `drand48' and friends provide a 48-bit random
220 * Ulrich Drepper has contributed new reentrant counterparts for the
221 `random' and `hsearch' families of functions; `random_r', `hsearch_r', etc.
223 * Ulrich Drepper has contributed new, highly-optimized versions of several
224 string functions for the i486/Pentium family of processors.
226 * Ulrich Drepper has updated the Linux-specific code, based largely
227 on work done in Hongjiu Lu's version of GNU libc for Linux.
228 The GNU library now supports Linux versions 2.0.10 and later,
229 using the ELF object file format (i[3456]86-*-linux).
231 * Andreas Schwab has ported the C library to Linux/m68k (m68k-*-linux).
233 * David Mosberger-Tang and Richard Henderson have ported the C library
234 to Linux/Alpha (alpha-*-linux). Richard Henderson contributed the
235 dynamic linking support for ELF/Alpha.
237 * Richard Henderson contributed several Alpha optimized assembler function
238 for arithmetic and string handling.
240 * Ulrich Drepper has contributed a new set of message catalog functions to
241 support multiple languages using the <libintl.h> interface, for use with
242 his new package GNU gettext. Translation volunteers have contributed
243 catalogs of the library's messages in Spanish, German, and Korean.
245 * For compatibility with XPG4, Ulrich Drepper has contributed the `gencat'
246 program and the `catgets' function for reading the catalog files it
247 creates. (The <libintl.h> interface is preferred; we include the
248 <nl_types.h> interface using `catgets' only for source compatibility with
249 programs already written to use it.)
251 * New header file <values.h> gives SVID-compatible names for <limits.h>
254 * Various new macros, declarations, and small header files for compatibility
257 * New function `group_member' is a convenient way to check if a process has
258 a given effective group ID.
260 * When using GCC 2.7 and later, the socket functions are now declared in a
261 special way so that passing an argument of type `struct sockaddr_in *',
262 `struct sockaddr_ns *', or `struct sockaddr_un *' instead of the generic
263 `struct sockaddr *' type, does not generate a type-clash warning.
265 * New function `error' declared in header file <error.h> is a convenient
266 function for printing error messages and optionally exiting; this is the
267 canonical function used in GNU programs. The new functions `err', `warn',
268 and friends in header file <err.h> are the canonical 4.4 BSD interface for
269 doing the same thing.
271 * The <glob.h> interface has several new flags from 4.4 BSD that extend the
272 POSIX.2 `glob' function to do ~ and {...} expansion.
274 * New function `unsetenv' complements `setenv' for compatibility with 4.4 BSD.
275 `clearenv' which is used in POSIX.9 is also available.
277 * New function `getsid' returns session ID number on systems that support it.
279 * We have incorporated the 4.4 BSD `db' library (version 1.85). New header
280 files <db.h> and <mpool.h> provide a rich set of functions for several
281 types of simple databases stored in memory and in files, and <ndbm.h> is
282 an old `ndbm'-compatible interface using the `db' functions. Link with
283 `-ldb' to get these functions.
285 * New macro `strdupa' copies a string like `strdup', but uses local stack
286 space from `alloca' instead of dynamic heap space from `malloc'.
288 * New function `strnlen' is like `strlen' but searches only a given maximum
289 number of characters for the null terminator. `stpncpy', `strndup' and
290 `strndupa' are similar variants for the `stpcpy', `strdup' and `strdupa'
293 * New function `statfs' in header <sys/statfs.h>.
295 * The new <argz.h> and <envz.h> interfaces contributed by Miles Bader
296 provide convenient functions for operating on blocks of null-terminated
299 * A new suite of functions in <utmp.h> handle all the details of reading
300 and writing the utmp file.
302 * An implementation of the NIS/YP(tm) based NSS service was contributed by
305 * Paul Eggert and Ulrich Drepper modified the `strftime' function to be
306 completely POSIX compliant and also implemented the extended functionality
307 to handle alternate digit representation and alternate era date formats.
309 * Ulrich Drepper provided an implementation of the `strptime' function
310 defined in XPG4.2 which transforms a string into a `struct tm' value.
312 * Paul Eggert provided the tzselect shell script as part of the timezone
313 code. The shell script makes it easy to select the correct timezone
316 * The implementation of the malloc family of functions is completely replaced
317 by a new implementation by Doug Lea with many improvements by Wolfram Gloger.
318 The implementation uses the mmap function (if available) and it is
319 optimized for the use in multi threaded programs.
321 * Ulrich Drepper contributed a MD5 "encryption" for the crypt family of
322 functions. This new functionality is usable by specifying a special
323 salt string and it is compatible with implementation on *BSD systems.
325 * Lots of functions from the XPG4.2 standard were added by Ulrich Drepper:
326 `getsubopt' to handle second level command line options, `bsd_signal'
327 to access BSD style `signal' functionality, the obsolete `regexp' style
330 * the `lchown' function is available on system which support this
333 * The implementation of the shadow password handling function was contributed
336 * David Mosberger-Tang changed the SunRPC implementation to be 64bit safe.
338 * POSIX.1g support was added. The <sys/select.h> header is available,
339 `isfdtype' and `pselect' are implemented. Craig Metz contributed an
340 implementation of `getaddrinfo'.
344 * For cross-compilation you should now set `BUILD_CC' instead of `HOST_CC'.
346 * New header file <fstab.h> and new functions `getfsspec', `getfsent' and
347 friends, for parsing /etc/fstab. This code comes from 4.4 BSD.
349 * The new function `daemon' from 4.4 BSD is useful for server programs that
350 want to put themselves in the background.
352 * Joel Sherrill has contributed support for several standalone boards that
353 run without an operating system.
355 * `printf', `scanf' and friends now accept a `q' type modifier for long
356 long int as well as `ll'. Formats using these might be `%qu' or `%lld'.
358 * All of the code taken from BSD (notably most of the math and networking
359 routines) has been updated from the BSD 4.4-Lite release.
361 * The resolver code has been updated from the BIND-4.9.3-BETA9 release.
363 * The new functions `getdomainname' and `setdomainname' fetch or change the
364 YP/NIS domain name. These are system calls which exist on systems which
367 * The time zone data files have been updated for the latest international
370 * The SunRPC programs `portmap' and `rpcinfo' are now installed in
371 $(sbindir) (usually /usr/local/sbin) instead of $(bindir).
375 * The C library now includes support for Sun RPC, from Sun's free
376 RPCSRC-4.0 distribution. The `portmap', `rpcinfo', and `rpcgen' programs
377 are included. (There is still no support for YP.)
379 * Tom Quinn has contributed a port of the C library to SGI machines running
380 Irix 4 (mips-sgi-irix4).
382 * The new `lockf' function is a simplified interface to the locking
383 facilities of `fcntl', included for compatibility.
385 * New time functions `timegm', `timelocal', and `dysize' for compatibility.
387 * New header file <sys/timeb.h> and new function `ftime' for compatibility.
389 * New header files <poll.h> and <sys/poll.h> and new function `poll' for
392 * The error message printed by `assert' for a failed assertion now includes
393 the name of the program (if using GNU ld) and the name of the calling
394 function (with versions of GCC that support this).
396 * The `psignal' function is now declared in <signal.h>, not <stdio.h>.
398 * The library now includes the <sys/mman.h> header file and memory
399 management functions `mmap', `munmap', `mprotect', `msync', and
400 `madvise', on systems that support those facilities.
402 * The interface for `mcheck' has changed slightly: the function called to
403 abort the program when an allocation inconsistency is detected now takes
404 an argument that indicates the type of failure. The new function
405 `mprobe' lets you request a consistency check for a particular block at
406 any time (checks are normally done only when you call `free' or `realloc'
409 * It is now possible to easily cross-compile the C library, building on one
410 system a library to run on another machine and/or operating system. All
411 you need to do is set the variable `HOST_CC' in `configparms' to the
412 native compiler for programs to run on the machine you are building on (a
413 few generator programs are used on Unix systems); set `CC' to the
416 * The new function `fexecve' (only implemented on the GNU system) executes
417 a program file given a file descriptor already open on the file.
421 * Brendan Kehoe has contributed most of a port to the DEC Alpha
422 running OSF/1 (alpha-dec-osf1). He says it is 75% complete.
424 * You can set the variable `libprefix' in `configparms' to specify a prefix
425 to be prepended to installed library files; this makes it easy to install
426 the GNU C library to be linked as `-lgnuc' or whatever.
428 * The new `stpncpy' is a cross between `stpcpy' and `strncpy': It
429 copies a limited number of characters from a string, and returns the
430 address of the last character written.
432 * You no longer need to check for whether the installed `stddef.h' is
433 compatible with the GNU C library. configure now checks for you.
435 * You can now define a per-stream `fileno' function to convert the
436 stream's cookie into an integral file descriptor.
438 * ``malloc (0)'' no longer returns a null pointer. Instead, it
439 allocates zero bytes of storage, and returns a unique pointer which
440 you can pass to `realloc' or `free'. The behavior is undefined if
441 you dereference this pointer.
443 * The C library now runs on Sony NEWS m68k machines running either
444 NewsOS 3 or NewsOS 4.
446 * The new `syscall' function is a system-dependent primitive function
447 for invoking system calls. It has the canonical behavior on Unix
448 systems, including unreliable return values for some calls (such as
449 `pipe', `fork' and `getppid').
451 * The error code `EWOULDBLOCK' is now obsolete; it is always defined
452 to `EAGAIN', which is the preferred name. On systems whose kernels
453 use two distinct codes, the C library now translates EWOULDBLOCK to
454 EAGAIN in every system call function.
458 * The GNU C Library Reference Manual is now distributed with the library.
459 `make dvi' will produce a DVI file of the printed manual.
460 `make info' will produce Info files that you can read on line using C-h i
461 in Emacs or the `info' program.
462 Please send comments on the manual to bug-glibc-manual@prep.ai.mit.edu.
464 * The library now supports SVR4 on i386s (i386-unknown-sysv4).
466 * Brendan Kehoe has contributed a port to Sun SPARCs running Solaris 2.
468 * Jason Merrill has contributed a port to the Sequent Symmetry running
469 Dynix version 3 (i386-sequent-dynix).
471 * The library has been ported to i386s running SCO 3.2.4 (also known as SCO
472 ODT 2.0; i386-unknown-sco3.2.4) or SCO 3.2 (i386-unknown-sco3.2).
474 * New function `memory_warnings' lets you arrange to get warnings when
475 malloc is running out of memory to allocate, like Emacs gives you.
477 * The C library now contains the relocating allocator used in Emacs 19 for
478 its editing buffers. This allocator (ralloc) minimizes allocation
479 overhead and fragmentation by moving allocated regions around whenever it
480 needs to. You always refer to a ralloc'd region with a "handle" (a
481 pointer to a pointer--an object of type `void **').
483 * There is a new `printf' format: `%m' gives you the string corresponding
484 to the error code in `errno'.
486 * In `scanf' formats, you can now use `%as' or `%a[' to do the normal `%s'
487 or `%[' conversion, but instead of filling in a fixed-sized buffer you
488 pass, the `a' modifier says to fill in a `char **' you pass with a
491 * The `fnmatch' function supports the new flag bits `FNM_LEADING_DIR' and
492 `FNM_CASEFOLD'. `FNM_LEADING_DIR' lets a pattern like `foo*' match a
493 name like `foo/bar'. `FNM_CASEFOLD' says to ignore case in matching.
495 * `mkstemp' is a traditional Unix function to atomically create and open a
496 uniquely-named temporary file.
500 * The standard location for the file that says what the local timezone is
501 has changed again. It is now `/usr/local/etc/localtime' (or more
502 precisely, `${prefix}/etc/localtime') rather than `/etc/localtime'.
504 * The distribution no longer contains any files with names longer than 14
507 * `struct ttyent' has two new flag bits: TTY_TRUSTED and TTY_CONSOLE.
508 These are set by the new `trusted' and `console' keywords in `/etc/ttys'.
510 * New functions `ttyslot' and `syslog' from 4.4 BSD.
514 * The configuration process has changed quite a bit. The `configure'
515 script is now used just like the configuration scripts for other GNU
516 packages. The `sysdeps' directory hierarchy is much rearranged.
517 The file `INSTALL' explains the new scheme in detail.
519 * The header files no longer need to be processed into ANSI C and
520 traditional C versions. There is just one set of files to install, and
521 it will work with ANSI or old C compilers (including `gcc -traditional').
523 * Brendan Kehoe and Ian Lance Taylor have ported the library to the
524 MIPS DECStation running Ultrix 4.
526 * The Sun 4 startup code (crt0) can now properly load SunOS 4 shared libraries.
527 Tom Quinn contributed the initial code. The GNU C library can NOT yet be
528 made itself into a shared library.
530 * Yet further improved support for the i386, running 4.3 BSD-like systems
531 (such as Mach 3 with the Unix single-server), or System V.
533 * New function `strncasecmp' to do case-insensitive string comparison
536 * New function `strsep' is a reentrant alternative to `strtok'.
538 * New functions `scandir' and `alphasort' for searching directories.
540 * New function `setenv' is a better interface to `putenv'.
542 * Ian Lance Taylor has contributed an implementation of the SVID `ftw'
543 function for traversing a directory tree.
545 * The GNU obstack package is now also part of the C library.
546 The new function `open_obstack_stream' creates a stdio stream that
547 writes onto an obstack; `obstack_printf' and `obstack_vprintf' do
548 formatted output directly to an obstack.
550 * Miscellaneous new functions: reboot, nice, sigaltstack (4.4 BSD only),
551 cfmakeraw, getusershell, getpass, swab, getttyent, seteuid, setegid.
553 * `FNM_FILE_NAME' is another name for `FNM_PATHNAME', used with `fnmatch'.
555 * The new functions `strfry' and `memfrob' do mysterious and wonderful
556 things to your strings.
558 * There are some new test programs: test-fseek, testmb, and testrand.
560 * Some work has been done to begin porting the library to 4.4 BSD and Linux.
561 These ports are not finished, but are a good starting place for really
562 supporting those systems.
564 * `/etc/localtime' is now the standard location for the file that says what
565 the local timezone is, rather than `/usr/local/lib/zoneinfo/localtime'.
566 This follows the general principle that `/etc' is the place for all local
569 * The C library header files now use `extern "C"' when used by the C++
570 compiler, so the C library should now work with C++ code.
572 * The header file <bstring.h> is gone. <string.h> now declares bcopy,
573 bcmp, bzero, and ffs.
575 * Mike Haertel (of GNU e?grep and malloc fame) has written a new sorting
576 function which uses the `merge sort' algorithm, and is said to be
577 significantly faster than the old GNU `qsort' function. Merge sort is
578 now the standard `qsort' function. The new algorithm can require a lot
579 of temporary storage; so, the old sorting function is called when the
580 required storage is not available.
582 * The C library now includes Michael Glad's Ultra Fast Crypt, which
583 provides the Unix `crypt' function, plus some other entry points.
584 Because of the United States export restriction on DES implementations,
585 we are distributing this code separately from the rest of the C library.
586 There is an extra distribution tar file just for crypt; it is called
587 `glibc-VERSION-crypt.tar.Z', e.g. `glibc-1.04-crypt.tar.Z'. You can just
588 unpack the crypt distribution along with the rest of the C library and
589 build; you can also build the library without getting crypt. Users
590 outside the USA can get the crypt distribution via anonymous FTP from
591 ftp.uni-c.dk [129.142.6.74], or another archive site outside the U.S.
593 * The code and header files taken from 4.4 BSD have been updated with the
594 latest files released from Berkeley.
596 ----------------------------------------------------------------------
597 Copyright information:
599 Copyright (C) 1992, 93, 94, 95, 96 Free Software Foundation, Inc.
601 Permission is granted to anyone to make or distribute verbatim copies
602 of this document as received, in any medium, provided that the
603 copyright notice and this permission notice are preserved,
604 thus giving the recipient permission to redistribute in turn.
606 Permission is granted to distribute modified versions
607 of this document, or of portions of it,
608 under the above conditions, provided also that they
609 carry prominent notices stating who last changed them.
612 version-control: never