1 GNU C Library NEWS -- history of user-visible changes. 26 January 1997
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.ai.mit.edu>. Questions and suggestions should be send to
8 <bug-glibc@prep.ai.mit.edu>.
16 * fix complex problems in Berkeley DB code
20 * fixed lots of header problems (especially Linux/GNU specific)
22 * dynamic loader preserves all registers
24 * Roland McGrath provided support for handling of auxiliary objects in
25 the ELF dynamic loader.
27 * support for parallel builds is improved
31 * GNU extensions are no longer declared by default. To enable them you
32 must define the macro `_GNU_SOURCE' in your program or compile with
35 * The library has changed from using GNU ld symbol aliases to using weak
36 symbols where available. The ELF object file format supports weak
37 symbols; GNU ld also supports weak symbols in the a.out format. (There
38 is also now support for other GNU ld extensions in ELF. Use the
39 `--with-elf' option to configure to indicate you have ELF, and
40 `--with-gnu-ld' if using GNU ld.) This change resulted in the deletion
41 of many files which contained only symbol aliases, reducing the size of
42 the source and the compiled library; many other files were renamed to
43 less cryptic names previously occupied by the symbol alias files.
44 There is a new header file <elf.h> for programs which operate on
45 files in the ELF format.
47 * Converted to Autoconf version 2, so `configure' has more options.
48 Run `configure --help' to see the details.
50 * The library can now be configured to build profiling, highly-optimized
51 (but undebuggable), and/or shared libraries (ELF with GNU ld only). The
52 `--enable-profile', `--enable-omitfp', and `--enable-shared' options to
53 `configure' enable building these extra libraries. The shared library is
54 built by default when using both ELF and GNU ld. When shared libraries
55 are enabled, the new library `-ldl' is available for arbitrary run-time
56 loading of shared objects; its interface is defined in <dlfcn.h>. The
57 new header file <link.h> gives access to the internals of the run-time
58 dynamic linker, `ld.so'. The shell script `ldd' is similar to the
59 application of same name on other systems and it provides information
60 about dynamically linked binaries.
62 * The C library now provides the run-time support code for profiling
63 executables compiled with `-pg'. Programs can control the profiling code
64 through the interface in <sys/gmon.h>. The `gmon.out' files written by
65 the GNU C library can be read only by GNU `gprof' (from GNU binutils);
66 the support for this file format was contributed by David Mosberger-Tang.
68 * The math code has been replaced with a math library based on fdlibm from
69 Sun, and modified by JT Conklin and Ulrich Drepper with i387 support, by
70 Ian Taylor with `float' functions and by Ulrich Drepper with `long double'
71 functions. The math functions now reside in a separate library, so
72 programs using them will need to use `-lm' their linking commands.
74 * John C. Bowman contributed optimized ix87 assembler inline functions.
76 * Ulrich Drepper has contributed support for an `/etc/nsswitch.conf'
77 mechanism similar to that found in Solaris 2. This is now used for the
78 group, passwd, hosts, networks, services, protocols, rpc, ethers,
79 shadow, netgroup, publickey, and alias databases. The `nsswitch.conf'
80 file controls what services are used for each individual database. This
81 works by loading shared libraries with names specified in `nsswitch.conf',
82 so service modules can be changed or added at any time without even
83 relinking any program. Currently there are the file, db, and NIS based
84 NSS services available.
86 * The new functions `strtoq' and `strtouq' parse integer values from
87 strings, like `strtol' and `strtoul', but they return `long long int' and
88 `unsigned long long int' values, respectively (64-bit quantities).
90 * The new functions `strtof' and `strtold' parse floating-point values from
91 strings, like `strtod', but they return `float' and `long double' values,
92 respectively (on some machines `double' and `long double' are the same).
94 * Ulrich Drepper has contributed new implementations of the floating-point
95 printing and reading code used in the `printf' family of functions and
96 `strtod', `strtof', and `strtold'. These new functions are perfectly
97 accurate, and much faster than the old ones.
99 * The implementation of the POSIX locale model was completely rewritten by
100 Ulrich Drepper. This includes the new programs `localedef' and `locale'
101 to compile the POSIX locale definition.
103 * The former dummy implementations of the strcoll and strxfrm function are
104 now replaced by fully functional code contributed by Ulrich Drepper. The
105 collation information comes from the POSIX locale definitions.
107 * The new header <langinfo.h> defines an interface for accessing
108 various locale-dependent data (using the locale chosen with `setlocale').
110 * Ulrich Drepper has contributed a new suite of functions for operation on
111 wide-character and multibyte-character strings, in <wchar.h>;
112 and classification and case conversion of wide characters, in <wctype.h>.
113 These new functions are conforming to the ISO C, Amendement 1 specification.
115 * There is now a second implementation of the standard I/O library available.
116 It comes from GNU libg++ as was written by Per Bothner, heavily modified
117 by Hongjiu Lu and made thread safe by Ulrich Drepper.
119 * You can now use positional parameter specifications in format strings
120 for the `printf' and `scanf' families of functions. For example,
121 `printf ("Number %2$d, Mr %1$s\n", "Jones", 6);'' prints
122 ``Number 6, Mr Jones''. This is mainly useful when providing different
123 format strings for different languages, whose grammars may dictate
124 different orderings of the values being printed. To support this
125 feature, the interface for `register_printf_handler' has changed; see
126 the header file <printf.h> for details.
128 * The `printf' and `scanf' families of functions now understand a new
129 formatting flag for numeric conversions: the ' flag (e.g. %'d or %'f) says
130 to group numbers as indicated by the locale; for `scanf' and friends, this
131 says to accept as valid only a number with all the proper grouping
132 separators in the right places. In the default "C" locale, numbers are
133 not grouped; but locales for specific countries will define the usual
134 conventions (i.e. separate thousands with `,' in the US locale).
136 * The pgrp functions have been regularized, slightly incompatibly but much
137 less confusingly. The core functions are now `getpgid' and `setpgid',
138 which take arguments for the PID to operate on; the POSIX.1 `getpgrp' (no
139 argument) and BSD `setpgrp' (identical to `setpgid') functions are
140 provided for compatibility. There is no longer an incompatible `getpgrp'
141 with an argument declared under _BSD_SOURCE; no BSD code uses it.
143 * The new header file <fts.h> and suite of functions simplify programs that
144 operate on directory trees. This code comes from 4.4 BSD.
146 * The resolver code has been updated from the BIND 4.9.5-P1 release.
147 Parts of the code were heavily modified by Ulrich Drepper to fit in the
148 NSS scheme used in glibc.
150 * The new function `malloc_find_object_address' finds the starting address
151 of a malloc'd block, given any address within the block;
152 `malloc_object_allocated_size' returns the size of an allocated block;
153 and `malloc_walk' lets you walk through all allocated blocks. These can
154 be useful for debugging; see <malloc.h> for the interfaces.
156 * There is a new malloc debugging hook `__memalign_hook'.
158 * There are new typedefs `ushort' for `unsigned short int' and `uint' for
159 `unsigned int' in <sys/types.h>. These are for compatibility only and
160 their use is discouraged.
162 * The `-lmcheck' library to enable standard malloc debugging hooks is now
163 done differently, so that it works even without GNU ld.
165 * New function `euidaccess' checks allowed access to a file like `access',
166 but using the effective IDs instead of the real IDs.
168 * The time zone data files have been updated for the latest and greatest
169 local time conventions of the countries of the world.
171 * The new function `dirfd' extracts the file descriptor used by a DIR stream;
174 * The new functions `ecvt', `fcvt', and `gcvt' provide an obsolete interface
175 for formatting floating-point numbers. They are provided only for
176 compatibility; new programs should use `sprintf' instead. There are
177 also equivalent function for the `long double' floating-point type and
178 all functions also exist in a reentrant form.
180 * The new auxiliary library `-lutil' from 4.4 BSD contains various
181 functions for maintaining the login-record files (primarily of use to
182 system programs such as `login'), and convenient functions for
183 allocating and initializing a pseudo-terminal (pty) device.
185 * Ulrich Drepper has contributed new support for System V style
186 shared memory and IPC on systems that support it.
188 * Ulrich Drepper has contributed several miscellaneous new functions found
189 in System V: The `hsearch' family of functions provide an effective
190 implementation of hash tables; `a64l' and `l64a' provide a very simple
191 binary to ASCII mapping; `drand48' and friends provide a 48-bit random
194 * Ulrich Drepper has contributed new reentrant counterparts for the
195 `random' and `hsearch' families of functions; `random_r', `hsearch_r', etc.
197 * Ulrich Drepper has contributed new, highly-optimized versions of several
198 string functions for the i486/Pentium family of processors.
200 * Ulrich Drepper has updated the Linux-specific code, based largely
201 on work done in Hongjiu Lu's version of GNU libc for Linux.
202 The GNU library now supports Linux versions 2.0.10 and later,
203 using the ELF object file format (i[3456]86-*-linux).
205 * Andreas Schwab has ported the C library to Linux/m68k (m68k-*-linux).
207 * David Mosberger-Tang and Richard Henderson have ported the C library
208 to Linux/Alpha (alpha-*-linux). Richard Henderson contributed the
209 dynamic linking support for ELF/Alpha.
211 * Richard Henderson contributed several Alpha optimized assembler function
212 for arithmetic and string handling.
214 * Ulrich Drepper has contributed a new set of message catalog functions to
215 support multiple languages using the <libintl.h> interface, for use with
216 his new package GNU gettext. Translation volunteers have contributed
217 catalogs of the library's messages in Spanish, German, and Korean.
219 * For compatibility with XPG4, Ulrich Drepper has contributed the `gencat'
220 program and the `catgets' function for reading the catalog files it
221 creates. (The <libintl.h> interface is preferred; we include the
222 <nl_types.h> interface using `catgets' only for source compatibility with
223 programs already written to use it.)
225 * New header file <values.h> gives SVID-compatible names for <limits.h>
228 * Various new macros, declarations, and small header files for compatibility
231 * New function `group_member' is a convenient way to check if a process has
232 a given effective group ID.
234 * When using GCC 2.7 and later, the socket functions are now declared in a
235 special way so that passing an argument of type `struct sockaddr_in *',
236 `struct sockaddr_ns *', or `struct sockaddr_un *' instead of the generic
237 `struct sockaddr *' type, does not generate a type-clash warning.
239 * New function `error' declared in header file <error.h> is a convenient
240 function for printing error messages and optionally exiting; this is the
241 canonical function used in GNU programs. The new functions `err', `warn',
242 and friends in header file <err.h> are the canonical 4.4 BSD interface for
243 doing the same thing.
245 * The <glob.h> interface has several new flags from 4.4 BSD that extend the
246 POSIX.2 `glob' function to do ~ and {...} expansion.
248 * New function `unsetenv' complements `setenv' for compatibility with 4.4 BSD.
249 `clearenv' which is used in POSIX.9 is also available.
251 * New function `getsid' returns session ID number on systems that support it.
253 * We have incorporated the 4.4 BSD `db' library (version 1.85). New header
254 files <db.h> and <mpool.h> provide a rich set of functions for several
255 types of simple databases stored in memory and in files, and <ndbm.h> is
256 an old `ndbm'-compatible interface using the `db' functions. Link with
257 `-ldb' to get these functions.
259 * New macro `strdupa' copies a string like `strdup', but uses local stack
260 space from `alloca' instead of dynamic heap space from `malloc'.
262 * New function `strnlen' is like `strlen' but searches only a given maximum
263 number of characters for the null terminator. `stpncpy', `strndup' and
264 `strndupa' are similar variants for the `stpcpy', `strdup' and `strdupa'
267 * New function `statfs' in header <sys/statfs.h>.
269 * The new <argz.h> and <envz.h> interfaces contributed by Miles Bader
270 provide convenient functions for operating on blocks of null-terminated
273 * A new suite of functions in <utmp.h> handle all the details of reading
274 and writing the utmp file.
276 * An implementation of the NIS/YP(tm) based NSS service was contributed by
279 * Paul Eggert and Ulrich Drepper modified the `strftime' function to be
280 completely POSIX compliant and also implemented the extended functionality
281 to handle alternate digit representation and alternate era date formats.
283 * Ulrich Drepper provided an implementation of the `strptime' function
284 defined in XPG4.2 which transforms a string into a `struct tm' value.
286 * Paul Eggert provided the tzselect shell script as part of the timezone
287 code. The shell script makes it easy to select the correct timezone
290 * The implementation of the malloc family of functions is completely replaced
291 by a new implementation by Doug Lea with many improvements by Wolfram Gloger.
292 The implementation uses the mmap function (if available) and it is
293 optimized for the use in multi threaded programs.
295 * Ulrich Drepper contributed a MD5 "encryption" for the crypt family of
296 functions. This new functionality is usable by specifying a special
297 salt string and it is compatible with implementation on *BSD systems.
299 * Lots of functions from the XPG4.2 standard were added by Ulrich Drepper:
300 `getsubopt' to handle second level command line options, `bsd_signal'
301 to access BSD style `signal' functionality, the obsolete `regexp' style
304 * the `lchown' function is available on system which support this
307 * The implementation of the shadow password handling function was contributed
310 * David Mosberger-Tang changed the SunRPC implementation to be 64bit safe.
312 * POSIX.1g support was added. The <sys/select.h> header is available,
313 `isfdtype' and `pselect' are implemented. Craig Metz contributed an
314 implementation of `getaddrinfo'.
318 * For cross-compilation you should now set `BUILD_CC' instead of `HOST_CC'.
320 * New header file <fstab.h> and new functions `getfsspec', `getfsent' and
321 friends, for parsing /etc/fstab. This code comes from 4.4 BSD.
323 * The new function `daemon' from 4.4 BSD is useful for server programs that
324 want to put themselves in the background.
326 * Joel Sherrill has contributed support for several standalone boards that
327 run without an operating system.
329 * `printf', `scanf' and friends now accept a `q' type modifier for long
330 long int as well as `ll'. Formats using these might be `%qu' or `%lld'.
332 * All of the code taken from BSD (notably most of the math and networking
333 routines) has been updated from the BSD 4.4-Lite release.
335 * The resolver code has been updated from the BIND-4.9.3-BETA9 release.
337 * The new functions `getdomainname' and `setdomainname' fetch or change the
338 YP/NIS domain name. These are system calls which exist on systems which
341 * The time zone data files have been updated for the latest international
344 * The SunRPC programs `portmap' and `rpcinfo' are now installed in
345 $(sbindir) (usually /usr/local/sbin) instead of $(bindir).
349 * The C library now includes support for Sun RPC, from Sun's free
350 RPCSRC-4.0 distribution. The `portmap', `rpcinfo', and `rpcgen' programs
351 are included. (There is still no support for YP.)
353 * Tom Quinn has contributed a port of the C library to SGI machines running
354 Irix 4 (mips-sgi-irix4).
356 * The new `lockf' function is a simplified interface to the locking
357 facilities of `fcntl', included for compatibility.
359 * New time functions `timegm', `timelocal', and `dysize' for compatibility.
361 * New header file <sys/timeb.h> and new function `ftime' for compatibility.
363 * New header files <poll.h> and <sys/poll.h> and new function `poll' for
366 * The error message printed by `assert' for a failed assertion now includes
367 the name of the program (if using GNU ld) and the name of the calling
368 function (with versions of GCC that support this).
370 * The `psignal' function is now declared in <signal.h>, not <stdio.h>.
372 * The library now includes the <sys/mman.h> header file and memory
373 management functions `mmap', `munmap', `mprotect', `msync', and
374 `madvise', on systems that support those facilities.
376 * The interface for `mcheck' has changed slightly: the function called to
377 abort the program when an allocation inconsistency is detected now takes
378 an argument that indicates the type of failure. The new function
379 `mprobe' lets you request a consistency check for a particular block at
380 any time (checks are normally done only when you call `free' or `realloc'
383 * It is now possible to easily cross-compile the C library, building on one
384 system a library to run on another machine and/or operating system. All
385 you need to do is set the variable `HOST_CC' in `configparms' to the
386 native compiler for programs to run on the machine you are building on (a
387 few generator programs are used on Unix systems); set `CC' to the
390 * The new function `fexecve' (only implemented on the GNU system) executes
391 a program file given a file descriptor already open on the file.
395 * Brendan Kehoe has contributed most of a port to the DEC Alpha
396 running OSF/1 (alpha-dec-osf1). He says it is 75% complete.
398 * You can set the variable `libprefix' in `configparms' to specify a prefix
399 to be prepended to installed library files; this makes it easy to install
400 the GNU C library to be linked as `-lgnuc' or whatever.
402 * The new `stpncpy' is a cross between `stpcpy' and `strncpy': It
403 copies a limited number of characters from a string, and returns the
404 address of the last character written.
406 * You no longer need to check for whether the installed `stddef.h' is
407 compatible with the GNU C library. configure now checks for you.
409 * You can now define a per-stream `fileno' function to convert the
410 stream's cookie into an integral file descriptor.
412 * ``malloc (0)'' no longer returns a null pointer. Instead, it
413 allocates zero bytes of storage, and returns a unique pointer which
414 you can pass to `realloc' or `free'. The behavior is undefined if
415 you dereference this pointer.
417 * The C library now runs on Sony NEWS m68k machines running either
418 NewsOS 3 or NewsOS 4.
420 * The new `syscall' function is a system-dependent primitive function
421 for invoking system calls. It has the canonical behavior on Unix
422 systems, including unreliable return values for some calls (such as
423 `pipe', `fork' and `getppid').
425 * The error code `EWOULDBLOCK' is now obsolete; it is always defined
426 to `EAGAIN', which is the preferred name. On systems whose kernels
427 use two distinct codes, the C library now translates EWOULDBLOCK to
428 EAGAIN in every system call function.
432 * The GNU C Library Reference Manual is now distributed with the library.
433 `make dvi' will produce a DVI file of the printed manual.
434 `make info' will produce Info files that you can read on line using C-h i
435 in Emacs or the `info' program.
436 Please send comments on the manual to bug-glibc-manual@prep.ai.mit.edu.
438 * The library now supports SVR4 on i386s (i386-unknown-sysv4).
440 * Brendan Kehoe has contributed a port to Sun SPARCs running Solaris 2.
442 * Jason Merrill has contributed a port to the Sequent Symmetry running
443 Dynix version 3 (i386-sequent-dynix).
445 * The library has been ported to i386s running SCO 3.2.4 (also known as SCO
446 ODT 2.0; i386-unknown-sco3.2.4) or SCO 3.2 (i386-unknown-sco3.2).
448 * New function `memory_warnings' lets you arrange to get warnings when
449 malloc is running out of memory to allocate, like Emacs gives you.
451 * The C library now contains the relocating allocator used in Emacs 19 for
452 its editing buffers. This allocator (ralloc) minimizes allocation
453 overhead and fragmentation by moving allocated regions around whenever it
454 needs to. You always refer to a ralloc'd region with a "handle" (a
455 pointer to a pointer--an object of type `void **').
457 * There is a new `printf' format: `%m' gives you the string corresponding
458 to the error code in `errno'.
460 * In `scanf' formats, you can now use `%as' or `%a[' to do the normal `%s'
461 or `%[' conversion, but instead of filling in a fixed-sized buffer you
462 pass, the `a' modifier says to fill in a `char **' you pass with a
465 * The `fnmatch' function supports the new flag bits `FNM_LEADING_DIR' and
466 `FNM_CASEFOLD'. `FNM_LEADING_DIR' lets a pattern like `foo*' match a
467 name like `foo/bar'. `FNM_CASEFOLD' says to ignore case in matching.
469 * `mkstemp' is a traditional Unix function to atomically create and open a
470 uniquely-named temporary file.
474 * The standard location for the file that says what the local timezone is
475 has changed again. It is now `/usr/local/etc/localtime' (or more
476 precisely, `${prefix}/etc/localtime') rather than `/etc/localtime'.
478 * The distribution no longer contains any files with names longer than 14
481 * `struct ttyent' has two new flag bits: TTY_TRUSTED and TTY_CONSOLE.
482 These are set by the new `trusted' and `console' keywords in `/etc/ttys'.
484 * New functions `ttyslot' and `syslog' from 4.4 BSD.
488 * The configuration process has changed quite a bit. The `configure'
489 script is now used just like the configuration scripts for other GNU
490 packages. The `sysdeps' directory hierarchy is much rearranged.
491 The file `INSTALL' explains the new scheme in detail.
493 * The header files no longer need to be processed into ANSI C and
494 traditional C versions. There is just one set of files to install, and
495 it will work with ANSI or old C compilers (including `gcc -traditional').
497 * Brendan Kehoe and Ian Lance Taylor have ported the library to the
498 MIPS DECStation running Ultrix 4.
500 * The Sun 4 startup code (crt0) can now properly load SunOS 4 shared libraries.
501 Tom Quinn contributed the initial code. The GNU C library can NOT yet be
502 made itself into a shared library.
504 * Yet further improved support for the i386, running 4.3 BSD-like systems
505 (such as Mach 3 with the Unix single-server), or System V.
507 * New function `strncasecmp' to do case-insensitive string comparison
510 * New function `strsep' is a reentrant alternative to `strtok'.
512 * New functions `scandir' and `alphasort' for searching directories.
514 * New function `setenv' is a better interface to `putenv'.
516 * Ian Lance Taylor has contributed an implementation of the SVID `ftw'
517 function for traversing a directory tree.
519 * The GNU obstack package is now also part of the C library.
520 The new function `open_obstack_stream' creates a stdio stream that
521 writes onto an obstack; `obstack_printf' and `obstack_vprintf' do
522 formatted output directly to an obstack.
524 * Miscellaneous new functions: reboot, nice, sigaltstack (4.4 BSD only),
525 cfmakeraw, getusershell, getpass, swab, getttyent, seteuid, setegid.
527 * `FNM_FILE_NAME' is another name for `FNM_PATHNAME', used with `fnmatch'.
529 * The new functions `strfry' and `memfrob' do mysterious and wonderful
530 things to your strings.
532 * There are some new test programs: test-fseek, testmb, and testrand.
534 * Some work has been done to begin porting the library to 4.4 BSD and Linux.
535 These ports are not finished, but are a good starting place for really
536 supporting those systems.
538 * `/etc/localtime' is now the standard location for the file that says what
539 the local timezone is, rather than `/usr/local/lib/zoneinfo/localtime'.
540 This follows the general principle that `/etc' is the place for all local
543 * The C library header files now use `extern "C"' when used by the C++
544 compiler, so the C library should now work with C++ code.
546 * The header file <bstring.h> is gone. <string.h> now declares bcopy,
547 bcmp, bzero, and ffs.
549 * Mike Haertel (of GNU e?grep and malloc fame) has written a new sorting
550 function which uses the `merge sort' algorithm, and is said to be
551 significantly faster than the old GNU `qsort' function. Merge sort is
552 now the standard `qsort' function. The new algorithm can require a lot
553 of temporary storage; so, the old sorting function is called when the
554 required storage is not available.
556 * The C library now includes Michael Glad's Ultra Fast Crypt, which
557 provides the Unix `crypt' function, plus some other entry points.
558 Because of the United States export restriction on DES implementations,
559 we are distributing this code separately from the rest of the C library.
560 There is an extra distribution tar file just for crypt; it is called
561 `glibc-VERSION-crypt.tar.Z', e.g. `glibc-1.04-crypt.tar.Z'. You can just
562 unpack the crypt distribution along with the rest of the C library and
563 build; you can also build the library without getting crypt. Users
564 outside the USA can get the crypt distribution via anonymous FTP from
565 ftp.uni-c.dk [129.142.6.74], or another archive site outside the U.S.
567 * The code and header files taken from 4.4 BSD have been updated with the
568 latest files released from Berkeley.
570 ----------------------------------------------------------------------
571 Copyright information:
573 Copyright (C) 1992, 93, 94, 95, 96 Free Software Foundation, Inc.
575 Permission is granted to anyone to make or distribute verbatim copies
576 of this document as received, in any medium, provided that the
577 copyright notice and this permission notice are preserved,
578 thus giving the recipient permission to redistribute in turn.
580 Permission is granted to distribute modified versions
581 of this document, or of portions of it,
582 under the above conditions, provided also that they
583 carry prominent notices stating who last changed them.
586 version-control: never