GNU C Library NEWS -- history of user-visible changes. 26 January 1997 Copyright (C) 1992, 93, 94, 95, 96, 97 Free Software Foundation, Inc. See the end for copying conditions. Please send GNU C library bug reports using the `glibcbug' script to . Questions and suggestions should be send to . 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 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 . The new header file gives access to the internals of the run-time dynamic linker, `ld.so'. The shell script `ldd' is similar to the application of same name on other systems and it provides information about dynamically linked binaries. * 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 . 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 and Ulrich Drepper with i387 support, by Ian Taylor with `float' functions and by Ulrich Drepper with `long double' functions. The math functions now reside in a separate library, so programs using them will need to use `-lm' their linking commands. * John C. Bowman contributed optimized ix87 assembler inline functions. * 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, rpc, ethers, shadow, netgroup, publickey, and alias 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. Currently there are the file, db, and NIS based NSS services available. * 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 implementation of the POSIX locale model was completely rewritten by Ulrich Drepper. This includes the new programs `localedef' and `locale' to compile the POSIX locale definition. * The former dummy implementations of the strcoll and strxfrm function are now replaced by fully functional code contributed by Ulrich Drepper. The collation information comes from the POSIX locale definitions. * The new header 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 ; and classification and case conversion of wide characters, in . These new functions are conforming to the ISO C, Amendement 1 specification. * There is now a second implementation of the standard I/O library available. It comes from GNU libg++ as was written by Per Bothner, heavily modified by Hongjiu Lu and made thread safe by Ulrich Drepper. * 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 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 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-P1 release. Parts of the code were heavily modified by Ulrich Drepper to fit in the NSS scheme used in glibc. * 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 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 . 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 . * 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. There are also equivalent function for the `long double' floating-point type and all functions also exist in a reentrant form. * 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 2.0.10 and later, using the ELF object file format (i[3456]86-*-linux). * Andreas Schwab has ported the C library to Linux/m68k (m68k-*-linux). * David Mosberger-Tang and Richard Henderson have ported the C library to Linux/Alpha (alpha-*-linux). Richard Henderson contributed the dynamic linking support for ELF/Alpha. * Richard Henderson contributed several Alpha optimized assembler function for arithmetic and string handling. * Ulrich Drepper has contributed a new set of message catalog functions to support multiple languages using the 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 interface is preferred; we include the interface using `catgets' only for source compatibility with programs already written to use it.) * New header file gives SVID-compatible names for 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 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 are the canonical 4.4 BSD interface for doing the same thing. * The 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. `clearenv' which is used in POSIX.9 is also available. * 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 and provide a rich set of functions for several types of simple databases stored in memory and in files, and 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. `stpncpy', `strndup' and `strndupa' are similar variants for the `stpcpy', `strdup' and `strdupa' function. * New function `statfs' in header . * The new and interfaces contributed by Miles Bader provide convenient functions for operating on blocks of null-terminated strings. * A new suite of functions in handle all the details of reading and writing the utmp file. * An implementation of the NIS/YP(tm) based NSS service was contributed by Thorsten Kukuk. * Paul Eggert and Ulrich Drepper modified the `strftime' function to be completely POSIX compliant and also implemented the extended functionality to handle alternate digit representation and alternate era date formats. * Ulrich Drepper provided an implementation of the `strptime' function defined in XPG4.2 which transforms a string into a `struct tm' value. * Paul Eggert provided the tzselect shell script as part of the timezone code. The shell script makes it easy to select the correct timezone specification. * The implementation of the malloc family of functions is completely replaced by a new implementation by Doug Lea with many improvements by Wolfram Gloger. The implementation uses the mmap function (if available) and it is optimized for the use in multi threaded programs. * Ulrich Drepper contributed a MD5 "encryption" for the crypt family of functions. This new functionality is usable by specifying a special salt string and it is compatible with implementation on *BSD systems. * Lots of functions from the XPG4.2 standard were added by Ulrich Drepper: `getsubopt' to handle second level command line options, `bsd_signal' to access BSD style `signal' functionality, the obsolete `regexp' style expression matcher. * the `lchown' function is available on system which support this functionality. * The implementation of the shadow password handling function was contributed by Ulrich Drepper. * David Mosberger-Tang changed the SunRPC implementation to be 64bit safe. * POSIX.1g support was added. The header is available, `isfdtype' and `pselect' are implemented. Craig Metz contributed an implementation of `getaddrinfo'. Version 1.09 * For cross-compilation you should now set `BUILD_CC' instead of `HOST_CC'. * New header file 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). 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 and new function `ftime' for compatibility. * New header files and 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 , not . * The library now includes the 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. 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. 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. 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. 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 is gone. 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. ---------------------------------------------------------------------- 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. Local variables: version-control: never end: