update from main archive 970121

[glibc.git] / NEWS

GNU C Library NEWS -- history of user-visible changes.  25 August 1996

Copyright (C) 1992, 93, 94, 95, 96 Free Software Foundation, Inc.
See the end for copying conditions.

Please send GNU C library bug reports to bug-glibc@prep.ai.mit.edu.
\f
Version 2.0

* GNU extensions are no longer declared by default.  To enable them you
  must define the macro `_GNU_SOURCE' in your program or compile with
  `-D_GNU_SOURCE'.

* The library has changed from using GNU ld symbol aliases to using weak
  symbols where available.  The ELF object file format supports weak
  symbols; GNU ld also supports weak symbols in the a.out format.  (There
  is also now support for other GNU ld extensions in ELF.  Use the
  `--with-elf' option to configure to indicate you have ELF, and
  `--with-gnu-ld' if using GNU ld.)  This change resulted in the deletion
  of many files which contained only symbol aliases, reducing the size of
  the source and the compiled library; many other files were renamed to
  less cryptic names previously occupied by the symbol alias files.
  There is a new header file <elf.h> for programs which operate on
  files in the ELF format.

* Converted to Autoconf version 2, so `configure' has more options.
  Run `configure --help' to see the details.

* The library can now be configured to build profiling, highly-optimized
  (but undebuggable), and/or shared libraries (ELF with GNU ld only).  The
  `--enable-profile', `--enable-omitfp', and `--enable-shared' options to
  `configure' enable building these extra libraries.  The shared library is
  built by default when using both ELF and GNU ld.  When shared libraries
  are enabled, the new library `-ldl' is available for arbitrary run-time
  loading of shared objects; its interface is defined in <dlfcn.h>.  The
  new header file <link.h> gives access to the internals of the run-time
  dynamic linker, `ld.so'.

* The C library now provides the run-time support code for profiling
  executables compiled with `-pg'.  Programs can control the profiling code
  through the interface in <sys/gmon.h>.  The `gmon.out' files written by
  the GNU C library can be read only by GNU `gprof' (from GNU binutils);
  the support for this file format was contributed by David Mosberger-Tang.

* The math code has been replaced with a math library based on fdlibm from
  Sun, and modified by JT Conklin with i387 support and by Ian Taylor with
  `float' functions.  The math functions now reside in a separate library,
  so programs using them will need to use `-lm' their linking commands.

* Ulrich Drepper has contributed support for an `/etc/nsswitch.conf'
  mechanism similar to that found in Solaris 2.  This is now used for the
  group, passwd, hosts, networks, services, protocols, and rpc databases.
  The `nsswitch.conf' file controls what services are used for each
  individual database.  This works by loading shared libraries with names
  specified in `nsswitch.conf', so service modules can be changed or added at
  any time without even relinking any program.  A future release of the
  separate NYS package will provide NIS/YP and NIS+ modules for this interface.

* The new functions `strtoq' and `strtouq' parse integer values from
  strings, like `strtol' and `strtoul', but they return `long long int' and
  `unsigned long long int' values, respectively (64-bit quantities).

* The new functions `strtof' and `strtold' parse floating-point values from
  strings, like `strtod', but they return `float' and `long double' values,
  respectively (on some machines `double' and `long double' are the same).

* Ulrich Drepper has contributed new implementations of the floating-point
  printing and reading code used in the `printf' family of functions and
  `strtod', `strtof', and `strtold'.  These new functions are perfectly
  accurate, and much faster than the old ones.

* The new header <langinfo.h> defines an interface for accessing
  various locale-dependent data (using the locale chosen with `setlocale').

* Ulrich Drepper has contributed a new suite of functions for operation on
  wide-character and multibyte-character strings, in <wcstr.h> and <mbstr.h>;
  and classification and case conversion of wide characters, in <wctype.h>.
  These new functions are intended to conform to the ISO C specification.

* You can now use positional parameter specifications in format strings
  for the `printf' and `scanf' families of functions.  For example,
  `printf ("Number %2$d, Mr %1$s\n", "Jones", 6);'' prints
  ``Number 6, Mr Jones''.  This is mainly useful when providing different
  format strings for different languages, whose grammars may dictate
  different orderings of the values being printed.  To support this
  feature, the interface for `register_printf_handler' has changed; see
  the header file <printf.h> for details.

* The `printf' and `scanf' families of functions now understand a new
  formatting flag for numeric conversions: the ' flag (e.g. %'d or %'f) says
  to group numbers as indicated by the locale; for `scanf' and friends, this
  says to accept as valid only a number with all the proper grouping
  separators in the right places.  In the default "C" locale, numbers are
  not grouped; but locales for specific countries will define the usual
  conventions (i.e. separate thousands with `,' in the US locale).

* The pgrp functions have been regularized, slightly incompatibly but much
  less confusingly.  The core functions are now `getpgid' and `setpgid',
  which take arguments for the PID to operate on; the POSIX.1 `getpgrp' (no
  argument) and BSD `setpgrp' (identical to `setpgid') functions are
  provided for compatibility.  There is no longer an incompatible `getpgrp'
  with an argument declared under _BSD_SOURCE; no BSD code uses it.

* The new header file <fts.h> and suite of functions simplify programs that
  operate on directory trees.  This code comes from 4.4 BSD.

* The resolver code has been updated from the BIND 4.9.5-T4B release.

* The new function `malloc_find_object_address' finds the starting address
  of a malloc'd block, given any address within the block;
  `malloc_object_allocated_size' returns the size of an allocated block;
  and `malloc_walk' lets you walk through all allocated blocks.  These can
  be useful for debugging; see <malloc.h> for the interfaces.

* There is a new malloc debugging hook `__memalign_hook'.

* There are new typedefs `ushort' for `unsigned short int' and `uint' for
  `unsigned int' in <sys/types.h>.  These are for compatibility only and
  their use is discouraged.

* The `-lmcheck' library to enable standard malloc debugging hooks is now
  done differently, so that it works even without GNU ld.

* New function `euidaccess' checks allowed access to a file like `access',
  but using the effective IDs instead of the real IDs.

* The time zone data files have been updated for the latest and greatest
  local time conventions of the countries of the world.

* The new function `dirfd' extracts the file descriptor used by a DIR stream;
  see <dirent.h>.

* The new functions `ecvt', `fcvt', and `gcvt' provide an obsolete interface
  for formatting floating-point numbers.  They are provided only for
  compatibility; new programs should use `sprintf' instead.

* The new auxiliary library `-lutil' from 4.4 BSD contains various
  functions for maintaining the login-record files (primarily of use to
  system programs such as `login'), and convenient functions for
  allocating and initializing a pseudo-terminal (pty) device.

* Ulrich Drepper has contributed new support for System V style
  shared memory and IPC on systems that support it.

* Ulrich Drepper has contributed several miscellaneous new functions found
  in System V: The `hsearch' family of functions provide an effective
  implementation of hash tables; `a64l' and `l64a' provide a very simple
  binary to ASCII mapping; `drand48' and friends provide a 48-bit random
  number generator.

* Ulrich Drepper has contributed new reentrant counterparts for the
  `random' and `hsearch' families of functions; `random_r', `hsearch_r', etc.

* Ulrich Drepper has contributed new, highly-optimized versions of several
  string functions for the i486/Pentium family of processors.

* Ulrich Drepper has updated the Linux-specific code, based largely
  on work done in Hongjiu Lu's version of GNU libc for Linux.
  The GNU library now supports Linux versions 1.3.29 and later,
  using the ELF object file format (i[345]86-*-linux).

* Andreas Schwab has ported the C library to Linux/m68k (m68k-*-linux).

* David Mosberger-Tang has ported the C library to Linux/Alpha (alpha-*-linux).
  Richard Henderson contributed the dynamic linking support for ELF/Alpha.

* Ulrich Drepper has contributed a new set of message catalog functions to
  support multiple languages using the <libintl.h> interface, for use with
  his new package GNU gettext.  Translation volunteers have contributed
  catalogs of the library's messages in Spanish, German, and Korean.

* For compatibility with XPG4, Ulrich Drepper has contributed the `gencat'
  program and the `catgets' function for reading the catalog files it
  creates.  (The <libintl.h> interface is preferred; we include the
  <nl_types.h> interface using `catgets' only for source compatibility with
  programs already written to use it.)

* New header file <values.h> gives SVID-compatible names for <limits.h>
  constants.

* Various new macros, declarations, and small header files for compatibility
  with 4.4 BSD.

* New function `group_member' is a convenient way to check if a process has
  a given effective group ID.

* When using GCC 2.7 and later, the socket functions are now declared in a
  special way so that passing an argument of type `struct sockaddr_in *',
  `struct sockaddr_ns *', or `struct sockaddr_un *' instead of the generic
  `struct sockaddr *' type, does not generate a type-clash warning.

* New function `error' declared in header file <error.h> is a convenient
  function for printing error messages and optionally exiting; this is the
  canonical function used in GNU programs.  The new functions `err', `warn',
  and friends in header file <err.h> are the canonical 4.4 BSD interface for
  doing the same thing.

* The <glob.h> interface has several new flags from 4.4 BSD that extend the
  POSIX.2 `glob' function to do ~ and {...} expansion.

* New function `unsetenv' complements `setenv' for compatibility with 4.4 BSD.

* New function `getsid' returns session ID number on systems that support it.

* We have incorporated the 4.4 BSD `db' library (version 1.85).  New header
  files <db.h> and <mpool.h> provide a rich set of functions for several
  types of simple databases stored in memory and in files, and <ndbm.h> is
  an old `ndbm'-compatible interface using the `db' functions.  Link with
  `-ldb' to get these functions.

* New macro `strdupa' copies a string like `strdup', but uses local stack
  space from `alloca' instead of dynamic heap space from `malloc'.

* New function `strnlen' is like `strlen' but searches only a given maximum
  number of characters for the null terminator.

* New function `statfs' in header <sys/statfs.h>.

* The new <argz.h> and <envz.h> interfaces contributed by Miles Bader
  provide convenient functions for operating on blocks of null-terminated
  strings.

* A new suite of functions in <utmp.h> handle all the details of reading
  and writing the utmp file.
\f
Version 1.09

* For cross-compilation you should now set `BUILD_CC' instead of `HOST_CC'.

* New header file <fstab.h> and new functions `getfsspec', `getfsent' and
  friends, for parsing /etc/fstab.  This code comes from 4.4 BSD.

* The new function `daemon' from 4.4 BSD is useful for server programs that
  want to put themselves in the background.

* Joel Sherrill has contributed support for several standalone boards that
  run without an operating system.

* `printf', `scanf' and friends now accept a `q' type modifier for long
  long int as well as `ll'.  Formats using these might be `%qu' or `%lld'.

* All of the code taken from BSD (notably most of the math and networking
  routines) has been updated from the BSD 4.4-Lite release.

* The resolver code has been updated from the BIND-4.9.3-BETA9 release.

* The new functions `getdomainname' and `setdomainname' fetch or change the
  YP/NIS domain name.  These are system calls which exist on systems which
  have YP (aka NIS).

* The time zone data files have been updated for the latest international
  conventions.

* The SunRPC programs `portmap' and `rpcinfo' are now installed in
  $(sbindir) (usually /usr/local/sbin) instead of $(bindir).
\f
Version 1.08

* The C library now includes support for Sun RPC, from Sun's free
  RPCSRC-4.0 distribution.  The `portmap', `rpcinfo', and `rpcgen' programs
  are included.  (There is still no support for YP.)

* Tom Quinn has contributed a port of the C library to SGI machines running
  Irix 4 (mips-sgi-irix4).

* The new `lockf' function is a simplified interface to the locking
  facilities of `fcntl', included for compatibility.

* New time functions `timegm', `timelocal', and `dysize' for compatibility.

* New header file <sys/timeb.h> and new function `ftime' for compatibility.

* New header files <poll.h> and <sys/poll.h> and new function `poll' for
  compatibility.

* The error message printed by `assert' for a failed assertion now includes
  the name of the program (if using GNU ld) and the name of the calling
  function (with versions of GCC that support this).

* The `psignal' function is now declared in <signal.h>, not <stdio.h>.

* The library now includes the <sys/mman.h> header file and memory
  management functions `mmap', `munmap', `mprotect', `msync', and
  `madvise', on systems that support those facilities.

* The interface for `mcheck' has changed slightly: the function called to
  abort the program when an allocation inconsistency is detected now takes
  an argument that indicates the type of failure.  The new function
  `mprobe' lets you request a consistency check for a particular block at
  any time (checks are normally done only when you call `free' or `realloc'
  on a block).

* It is now possible to easily cross-compile the C library, building on one
  system a library to run on another machine and/or operating system.  All
  you need to do is set the variable `HOST_CC' in `configparms' to the
  native compiler for programs to run on the machine you are building on (a
  few generator programs are used on Unix systems); set `CC' to the
  cross-compiler.

* The new function `fexecve' (only implemented on the GNU system) executes
  a program file given a file descriptor already open on the file.
\f
Version 1.07

* Brendan Kehoe has contributed most of a port to the DEC Alpha
  running OSF/1 (alpha-dec-osf1).  He says it is 75% complete.

* You can set the variable `libprefix' in `configparms' to specify a prefix
  to be prepended to installed library files; this makes it easy to install
  the GNU C library to be linked as `-lgnuc' or whatever.

* The new `stpncpy' is a cross between `stpcpy' and `strncpy': It
  copies a limited number of characters from a string, and returns the
  address of the last character written.

* You no longer need to check for whether the installed `stddef.h' is
  compatible with the GNU C library.  configure now checks for you.

* You can now define a per-stream `fileno' function to convert the
  stream's cookie into an integral file descriptor.

* ``malloc (0)'' no longer returns a null pointer.  Instead, it
  allocates zero bytes of storage, and returns a unique pointer which
  you can pass to `realloc' or `free'.  The behavior is undefined if
  you dereference this pointer.

* The C library now runs on Sony NEWS m68k machines running either
  NewsOS 3 or NewsOS 4.

* The new `syscall' function is a system-dependent primitive function
  for invoking system calls.  It has the canonical behavior on Unix
  systems, including unreliable return values for some calls (such as
  `pipe', `fork' and `getppid').

* The error code `EWOULDBLOCK' is now obsolete; it is always defined
  to `EAGAIN', which is the preferred name.  On systems whose kernels
  use two distinct codes, the C library now translates EWOULDBLOCK to
  EAGAIN in every system call function.
\f
Version 1.06

* The GNU C Library Reference Manual is now distributed with the library.
  `make dvi' will produce a DVI file of the printed manual.
  `make info' will produce Info files that you can read on line using C-h i
  in Emacs or the `info' program.
  Please send comments on the manual to bug-glibc-manual@prep.ai.mit.edu.

* The library now supports SVR4 on i386s (i386-unknown-sysv4).

* Brendan Kehoe has contributed a port to Sun SPARCs running Solaris 2.

* Jason Merrill has contributed a port to the Sequent Symmetry running
  Dynix version 3 (i386-sequent-dynix).

* The library has been ported to i386s running SCO 3.2.4 (also known as SCO
  ODT 2.0; i386-unknown-sco3.2.4) or SCO 3.2 (i386-unknown-sco3.2).

* New function `memory_warnings' lets you arrange to get warnings when
  malloc is running out of memory to allocate, like Emacs gives you.

* The C library now contains the relocating allocator used in Emacs 19 for
  its editing buffers.  This allocator (ralloc) minimizes allocation
  overhead and fragmentation by moving allocated regions around whenever it
  needs to.  You always refer to a ralloc'd region with a "handle" (a
  pointer to a pointer--an object of type `void **').

* There is a new `printf' format: `%m' gives you the string corresponding
  to the error code in `errno'.

* In `scanf' formats, you can now use `%as' or `%a[' to do the normal `%s'
  or `%[' conversion, but instead of filling in a fixed-sized buffer you
  pass, the `a' modifier says to fill in a `char **' you pass with a
  malloc'd string.

* The `fnmatch' function supports the new flag bits `FNM_LEADING_DIR' and
  `FNM_CASEFOLD'.  `FNM_LEADING_DIR' lets a pattern like `foo*' match a
  name like `foo/bar'.  `FNM_CASEFOLD' says to ignore case in matching.

* `mkstemp' is a traditional Unix function to atomically create and open a
  uniquely-named temporary file.
\f
Version 1.05

* The standard location for the file that says what the local timezone is
  has changed again.  It is now `/usr/local/etc/localtime' (or more
  precisely, `${prefix}/etc/localtime') rather than `/etc/localtime'.

* The distribution no longer contains any files with names longer than 14
  characters.

* `struct ttyent' has two new flag bits: TTY_TRUSTED and TTY_CONSOLE.
  These are set by the new `trusted' and `console' keywords in `/etc/ttys'.

* New functions `ttyslot' and `syslog' from 4.4 BSD.
\f
Version 1.04

* The configuration process has changed quite a bit.  The `configure'
  script is now used just like the configuration scripts for other GNU
  packages.  The `sysdeps' directory hierarchy is much rearranged.
  The file `INSTALL' explains the new scheme in detail.

* The header files no longer need to be processed into ANSI C and
  traditional C versions.  There is just one set of files to install, and
  it will work with ANSI or old C compilers (including `gcc -traditional').

* Brendan Kehoe and Ian Lance Taylor have ported the library to the
  MIPS DECStation running Ultrix 4.

* The Sun 4 startup code (crt0) can now properly load SunOS 4 shared libraries.
  Tom Quinn contributed the initial code.  The GNU C library can NOT yet be
  made itself into a shared library.

* Yet further improved support for the i386, running 4.3 BSD-like systems
  (such as Mach 3 with the Unix single-server), or System V.

* New function `strncasecmp' to do case-insensitive string comparison
  with limited length.

* New function `strsep' is a reentrant alternative to `strtok'.

* New functions `scandir' and `alphasort' for searching directories.

* New function `setenv' is a better interface to `putenv'.

* Ian Lance Taylor has contributed an implementation of the SVID `ftw'
  function for traversing a directory tree.

* The GNU obstack package is now also part of the C library.
  The new function `open_obstack_stream' creates a stdio stream that
  writes onto an obstack; `obstack_printf' and `obstack_vprintf' do
  formatted output directly to an obstack.

* Miscellaneous new functions: reboot, nice, sigaltstack (4.4 BSD only),
  cfmakeraw, getusershell, getpass, swab, getttyent, seteuid, setegid.

* `FNM_FILE_NAME' is another name for `FNM_PATHNAME', used with `fnmatch'.

* The new functions `strfry' and `memfrob' do mysterious and wonderful
  things to your strings.

* There are some new test programs: test-fseek, testmb, and testrand.

* Some work has been done to begin porting the library to 4.4 BSD and Linux.
  These ports are not finished, but are a good starting place for really
  supporting those systems.

* `/etc/localtime' is now the standard location for the file that says what
  the local timezone is, rather than `/usr/local/lib/zoneinfo/localtime'.
  This follows the general principle that `/etc' is the place for all local
  configuration files.

* The C library header files now use `extern "C"' when used by the C++
  compiler, so the C library should now work with C++ code.

* The header file <bstring.h> is gone.  <string.h> now declares bcopy,
  bcmp, bzero, and ffs.

* Mike Haertel (of GNU e?grep and malloc fame) has written a new sorting
  function which uses the `merge sort' algorithm, and is said to be
  significantly faster than the old GNU `qsort' function.  Merge sort is
  now the standard `qsort' function.  The new algorithm can require a lot
  of temporary storage; so, the old sorting function is called when the
  required storage is not available.

* The C library now includes Michael Glad's Ultra Fast Crypt, which
  provides the Unix `crypt' function, plus some other entry points.
  Because of the United States export restriction on DES implementations,
  we are distributing this code separately from the rest of the C library.
  There is an extra distribution tar file just for crypt; it is called
  `glibc-VERSION-crypt.tar.Z', e.g. `glibc-1.04-crypt.tar.Z'.  You can just
  unpack the crypt distribution along with the rest of the C library and
  build; you can also build the library without getting crypt.  Users
  outside the USA can get the crypt distribution via anonymous FTP from
  ftp.uni-c.dk [129.142.6.74], or another archive site outside the U.S.

* The code and header files taken from 4.4 BSD have been updated with the
  latest files released from Berkeley.
\f
----------------------------------------------------------------------
Copyright information:

Copyright (C) 1992, 93, 94, 95, 96 Free Software Foundation, Inc.

   Permission is granted to anyone to make or distribute verbatim copies
   of this document as received, in any medium, provided that the
   copyright notice and this permission notice are preserved,
   thus giving the recipient permission to redistribute in turn.

   Permission is granted to distribute modified versions
   of this document, or of portions of it,
   under the above conditions, provided also that they
   carry prominent notices stating who last changed them.
\f
Local variables:
version-control: never
end: