1 Frequently Asked Question on GNU C Library
3 As every FAQ this one also tries to answer questions the user might have
4 when using the package. Please make sure you read this before sending
5 questions or bug reports to the maintainers.
7 The GNU C Library is very complex. The building process exploits the
8 features available in tools generally available. But many things can
9 only be done using GNU tools. Also the code is sometimes hard to
10 understand because it has to be portable but on the other hand must be
11 fast. But you need not understand the details to use GNU C Library.
12 This will only be necessary if you intend to contribute or change it.
14 If you have any questions you think should be answered in this document,
19 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
20 [Q1] ``What systems does the GNU C Library run on?''
22 [Q2] ``What compiler do I need to build GNU libc?''
24 [Q3] ``When starting make I get only error messages.
27 [Q4] ``After I changed configure.in I get `Autoconf version X.Y.
28 or higher is required for this script'. What can I do?''
30 [Q5] ``Do I need a special linker or archiver?''
32 [Q6] ``Do I need some more things to compile GNU C Library?''
34 [Q7] ``When I run `nm -u libc.so' on the produced library I still
35 find unresolved symbols? Can this be ok?''
37 [Q8] ``Can I replace the libc on my Linux system with GNU libc?''
39 [Q9] ``I expect GNU libc to be 100% source code compatible with
40 the old Linux based GNU libc. Why isn't it like this?''
42 [Q10] ``Why does getlogin() always return NULL on my Linux box?''
44 [Q11] ``Where are the DST_* constants found in <sys/time.h> on many
47 [Q12] ``The `gencat' utility cannot process the input which are
48 successfully used on my Linux libc based system. Why?''
50 [Q13] ``How do I configure GNU libc so that the essential libraries
51 like libc.so go into /lib and the other into /usr/lib?''
53 [Q14] ``When linking with the new libc I get unresolved symbols
54 `crypt' and `setkey'. Why aren't these functions in the
57 [Q15] ``What are these `add-ons'?''
59 [Q16] ``When I use GNU libc on my Linux system by linking against
60 to libc.so which comes with glibc all I get is a core dump.''
62 [Q17] ``Looking through the shared libc file I haven't found the
63 functions `stat', `lstat', `fstat', and `mknod' and while
64 linking on my Linux system I get error messages. How is
65 this supposed to work?''
67 [Q18] ``The prototypes for `connect', `accept', `getsockopt',
68 `setsockopt', `getsockname', `getpeername', `send',
69 `sendto', and `recvfrom' are different in GNU libc than
70 on any other system I saw. This is a bug, isn't it?''
72 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
73 [Q1] ``What systems does the GNU C Library run on?''
75 [A1] {UD} This is difficult to answer. The file `README' lists the
76 architectures GNU libc is known to run *at some time*. This does not
77 mean that it still can be compiled and run on them in the moment.
79 The systems glibc is known to work on in the moment and most probably
83 i[3456]86-*-linux-gnu Linux-2.0 on Intel
84 m68k-*-linux-gnu Linux-2.0 on Motorola 680x0
85 alpha-*-linux-gnu Linux-2.0 on DEC Alpha
87 Other Linux platforms are also on the way to be supported but I need
88 some success reports first.
90 If you have a system not listed above (or in the `README' file) and
91 you are really interested in porting it, contact
93 <bug-glibc@prep.ai.mit.edu>
96 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
97 [Q2] ``What compiler do I need to build GNU libc?''
99 [A2] {UD} It is (almost) impossible to compile GNU C Library using a
100 different compiler than GNU CC. A lot of extensions of GNU CC are
101 used to increase the portability and speed.
103 But this does not mean you have to use GNU CC for using the GNU C
104 Library. In fact you should be able to use the native C compiler
105 because the success only depends on the binutils: the linker and
108 The GNU CC is found like all other GNU packages on
109 ftp://prep.ai.mit.edu/pub/gnu
110 or better one of the many mirror sites.
112 You always should try to use the latest official release. Older
113 versions might not have all the features GNU libc could use.
116 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
117 [Q3] ``When starting `make' I get only errors messages.
120 [A3] {UD} You definitely need GNU make to translate GNU libc. No
121 other make program has the needed functionality.
123 Versions before 3.74 have bugs which prevent correct execution so you
124 should upgrade to the latest version before starting the compilation.
127 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
128 [Q4] ``After I changed configure.in I get `Autoconf version X.Y.
129 or higher is required for this script'. What can I do?''
131 [A4] {UD} You have to get the specified autoconf version (or a later)
132 from your favourite mirror of prep.ai.mit.edu.
135 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
136 [Q5] ``Do I need a special linker or archiver?''
138 [A5] {UD} If your native versions are not too buggy you can probably
139 work with them. But GNU libc works best with GNU binutils.
141 On systems where the native linker does not support weak symbols you
142 will not get a really ISO C compliant C library. Generally speaking
143 you should use the GNU binutils if they provide at least the same
144 functionality as your system's tools.
146 Always get the newest release of GNU binutils available.
147 Older releases are known to have bugs that affect building the GNU C
151 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
152 [Q6] ``Do I need some more things to compile GNU C Library?''
154 [A6] {UD} Yes, there are some more :-).
156 * GNU gettext; the GNU libc is internationalized and partly localized.
157 For bringing the messages for the different languages in the needed
158 form the tools from the GNU gettext package are necessary. See
159 ftp://prep.ai.mit.edu/pub/gnu or better any mirror site.
161 * lots of diskspace (for i?86-linux this means, e.g., ~70MB).
163 You should avoid compiling on a NFS mounted device. This is very
166 * plenty of time (approx 1h for i?86-linux on i586@133 or 2.5h on
167 i486@66 or 4.5h on i486@33). For Hurd systems times are much higher.
169 If you have some more measurements let me know.
171 * When compiling for Linux:
173 + the header files of the Linux kernel must be available in the
174 search path of the CPP as <linux/*.h> and <asm/*.h>.
176 * Some files depend on special tools. E.g., files ending in .gperf
177 need a `gperf' program. The GNU version (part of libg++) is known
178 to work while some vendor versions do not.
180 You should not need these tools unless you change the source files.
182 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
183 [Q7] ``When I run `nm -u libc.so' on the produced library I still
184 find unresolved symbols? Can this be ok?''
186 [A7] {UD} Yes, this is ok. There can be several kinds of unresolved
189 * magic symbols automatically generated by the linker. Names are
190 often like __start_* and __stop_*
192 * symbols starting with _dl_* come from the dynamic linker
194 * symbols resolved by using libgcc.a
195 (__udivdi3, __umoddi3, or similar)
197 * weak symbols, which need not be resolved at all
198 (currently fabs among others; this gets resolved if the program
199 is linked against libm, too.)
201 Generally, you should make sure you find a real program which produces
202 errors while linking before deciding there is a problem.
205 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
206 [Q8] ``Can I replace the libc on my Linux system with GNU libc?''
208 [A8] {UD} You cannot replace any existing libc for Linux with GNU
209 libc. There are different versions of C libraries and you can run
210 libcs with different major version independently.
212 For Linux there are today two libc versions:
213 libc-4 old a.out libc
214 libc-5 current ELF libc
216 GNU libc will have the major number 6 and therefore you can have this
217 additionally installed. For more information consult documentation for
218 shared library handling. The Makefiles of GNU libc will automatically
219 generate the needed symbolic links which the linker will use.
222 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
223 [Q9] ``I expect GNU libc to be 100% source code compatible with
224 the old Linux based GNU libc. Why isn't it like this?''
226 [A9] {DMT,UD} Not every extension in Linux libc's history was well
227 thought-out. In fact it had a lot of problems with standards compliance
228 and with cleanliness. With the introduction of a new version number these
229 errors now can be corrected. Here is a list of the known source code
232 * _GNU_SOURCE: glibc does not automatically define _GNU_SOURCE. Thus,
233 if a program depends on GNU extensions or some other non-standard
234 functionality, it is necessary to compile it with C compiler option
235 -D_GNU_SOURCE, or better, to put `#define _GNU_SOURCE' at the beginning
236 of your source files, before any C library header files are included.
237 This difference normally manifests itself in the form of missing
238 prototypes and/or data type definitions. Thus, if you get such errors,
239 the first thing you should do is try defining _GNU_SOURCE and see if
240 that makes the problem go away.
242 For more information consult the file `NOTES' part of the GNU C
245 * reboot(): GNU libc sanitizes the interface of reboot() to be more
246 compatible with the interface used on other OSes. In particular,
247 reboot() as implemented in glibc takes just one argument. This argument
248 corresponds to the third argument of the Linux reboot system call.
249 That is, a call of the form reboot(a, b, c) needs to be changed into
251 Beside this the header <sys/reboot.h> defines the needed constants
252 for the argument. These RB_* constants should be used instead of the
253 cryptic magic numbers.
255 * swapon(): the interface of this function didn't changed, but the
256 prototype is in a separate header file <sys/swap.h>. For the additional
257 argument of of swapon() you should use the SWAP_* constants from
258 <linux/swap.h>, which get defined when <sys/swap.h> is included.
260 * errno: If a program uses variable "errno", then it _must_ include header
261 file <errno.h>. The old libc often (erroneously) declared this variable
262 implicitly as a side-effect of including other libc header files. glibc
263 is careful to avoid such namespace pollution, which, in turn, means that
264 you really need to include the header files that you depend on. This
265 difference normally manifests itself in the form of the compiler
266 complaining about the references of the undeclared symbol "errno".
268 * Linux-specific syscalls: All Linux system calls now have appropriate
269 library wrappers and corresponding declarations in various header files.
270 This is because the syscall() macro that was traditionally used to
271 work around missing syscall wrappers are inherently non-portable and
272 error-prone. The following tables lists all the new syscall stubs,
273 the header-file declaring their interface and the system call name.
275 syscall name: wrapper name: declaring header file:
276 ------------- ------------- ----------------------
277 bdflush bdflush <sys/kdaemon.h>
278 create_module create_module <sys/module.h>
279 delete_module delete_module <sys/module.h>
280 get_kernel_syms get_kernel_syms <sys/module.h>
281 init_module init_module <sys/module.h>
282 syslog ksyslog_ctl <sys/klog.h>
284 * lpd: Older versions of lpd depend on a routine called _validuser().
285 The library does not provide this function, but instead provides
286 __ivaliduser() which has a slightly different interfaces. Simply
287 upgrading to a newer lpd should fix this problem (e.g., the 4.4BSD
288 lpd is known to be working).
290 * resolver functions/BIND: like on many other systems the functions of
291 the resolver library are not included in the libc itself. There is
292 a separate library libresolv. If you find some symbols starting with
293 `res_*' undefined simply add -lresolv to your call of the linker.
296 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
297 [Q10] ``Why does getlogin() always return NULL on my Linux box?''
299 [A10] {UD} The GNU C library has a format for the UTMP and WTMP file
300 which differs from what your system currently has. It was extended to
301 fulfill the needs of the next years when IPv6 is introduced. So the
302 record size is different, fields might have a different position and
303 so reading the files written by functions from the one library cannot
304 be read by functions from the other library. Sorry, but this is what
305 a major release is for. It's better to have a cut now than having no
306 means to support the new techniques later.
309 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
310 [Q11] ``Where are the DST_* constants found in <sys/time.h> on many
313 [A11] {UD} These constants come from the old BSD days and are not used
314 today anymore (even the Linux based glibc does not implement the handling
315 although the constants are defined).
317 Instead GNU libc contains the zone database handling and compatibility
318 code for POSIX TZ environment variable handling.
321 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
322 [Q12] ``The `gencat' utility cannot process the input which are
323 successfully used on my Linux libc based system. Why?''
325 [A12] {UD} Unlike the author of the `gencat' program which is distributed
326 with Linux libc I have read the underlying standards before writing the
327 code. It is completely compatible with the specification given in
328 X/Open Portability Guide.
330 To ease the transition from the Linux version some of the non-standard
331 features are also present in the `gencat' program of GNU libc. This
332 mainly includes the use of symbols for the message number and the automatic
333 generation of header files which contain the needed #defines to map the
336 Here is a simple SED script to convert at least some Linux specific
337 catalog files to the XPG4 form:
339 -----------------------------------------------------------------------
340 # Change catalog source in Linux specific format to standard XPG format.
341 # Ulrich Drepper <drepper@cygnus.com>, 1996.
345 s/\$ #\([^ ]*\).*/\1/
347 s/\$ #[^ ]* *\(.*\)/\$ \1/
353 s/\(.*\)\n\(.*\)/\2 \1/
355 -----------------------------------------------------------------------
358 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
359 [Q13] ``How do I configure GNU libc so that the essential libraries
360 like libc.so go into /lib and the other into /usr/lib?''
362 [A13] {UD} Like all other GNU packages GNU libc is configured to use a
363 base directory and install all files relative to this. If you intend
364 to really use GNU libc on your system this base directory is /usr. I.e.,
366 configure --prefix=/usr <other_options>
368 Some systems like Linux have a filesystem standard which makes a
369 difference between essential libraries and others. Essential
370 libraries are placed in /lib because this directory is required to be
371 located on the same disk partition as /. The /usr subtree might be
372 found on another partition/disk.
374 To install the essential libraries which come with GNU libc in /lib
375 one must explicitly tell this. Autoconf has no option for this so you
376 have to use the file where all user supplied additional information
377 should go in: `configparms' (see the `INSTALL' file). For Linux the
378 `configparms' file should contain:
383 The first line specifies the directory for the essential libraries,
384 the second line the directory for file which are by tradition placed
385 in a directory named /etc.
388 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
389 [Q14] ``When linking with the new libc I get unresolved symbols
390 `crypt' and `setkey'. Why aren't these functions in the
393 [A14] {UD} Remember the US restrictions of exporting cryptographic
394 programs and source code. Until this law gets abolished we cannot
395 ship the cryptographic function together with the libc.
397 But of course we provide the code and there is an very easy way to use
398 this code. First get the extra package. People in the US way get it
399 from the same place they got the GNU libc from. People outside the US
400 should get the code from ftp.uni-c.dk [129.142.6.74], or another
401 archive site outside the USA. The README explains how to install the
404 If you already have the crypt code on your system the reason for the
405 failure is probably that you failed to link with -lcrypt. The crypto
406 functions are in a separate library to make it possible to export GNU
407 libc binaries from the US.
410 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
411 [Q15] ``What are these `add-ons'?''
413 [A15] {UD} To avoid complications with export rules or external source
414 code some optional parts of the libc are distributed as separate
415 packages (e.g., the crypt package, see Q14).
417 To ease the use as part of GNU libc the installer just has to unpack
418 the package and tell the configuration script about these additional
419 subdirectories using the --enable-add-ons option. When you add the
420 crypt add-on you just have to use
422 configure --enable-add-ons=des-crypt,XXX ...
424 where XXX are possible other add-ons and ... means the rest of the
427 You can use add-ons also to overwrite some files in glibc. The add-on
428 system dependent subdirs are search first. It is also possible to add
429 banner files (use a file named `Banner') or create shared libraries.
431 Using add-ons has the big advantage that the makefiles of the GNU libc
432 can be used. Only some few stub rules must be written to get
433 everything running. Even handling of architecture dependent
434 compilation is provided. The GNU libc's sysdeps/ directory shows how
438 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
439 [Q16] ``When I use GNU libc on my Linux system by linking against
440 to libc.so which comes with glibc all I get is a core dump.''
442 [A16] {UD} It is not enough to simply link against the GNU libc
443 library itself. The GNU C library comes with its own dynamic linker
444 which really conforms to the ELF API standard. This dynamic linker
447 Normally this is done by the compiler. The gcc will use
449 -dynamic-linker /lib/ld-linux.so.1
451 unless the user specifies her/himself a -dynamic-linker argument. But
452 this is not the correct name for the GNU dynamic linker. The correct
453 name is /lib/ld.so.1 which is the name specified in the SVr4 ABi.
455 To change your environment to use GNU libc for compiling you need to
456 change the `specs' file of your gcc. This file is normally found at
458 /usr/lib/gcc-lib/<arch>/<version>/specs
460 In this file you have to change a few things:
462 - change `ld-linux.so.1' to `ld.so.1' (or to ld-linux.so.2, see below)
464 - remove all expression `%{...:-lgmon}'; there is no libgmon in glibc
467 Things are getting a bit more complicated if you have GNU libc
468 installed in some other place than /usr, i.e., if you do not want to
469 use it instead of the old libc. In this case the needed startup files
470 and libraries are not found in the regular places. So the specs file
471 must tell the compiler and linker exactly what to use. Here is for
472 example the gcc-2.7.2 specs file when GNU libc is installed at
475 -----------------------------------------------------------------------
477 %{V} %{v:%{!V:-V}} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*} %{Wa,*:%*}
483 %{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{!m386:-D__i486__} %{posix:-D_POSIX_SOURCE} -I/home/gnu/include
492 %{!shared:crtend.o%s} %{shared:crtendS.o%s} /home/gnu/lib/crtn.o%s
495 -m elf_i386 -rpath=/home/gnu/lib -L/home/gnu/lib %{shared:-shared} %{!shared: %{!ibcs: %{!static: %{rdynamic:-export-dynamic} %{!dynamic-linker:-dynamic-linker=/home/gnu/lib/ld.so.1}} %{static:-static}}}
498 %{!shared: %{mieee-fp:-lieee} %{p:-lc_p} %{!p:%{pg:-lc_p} %{!pg:-lc}}}
504 %{!shared: %{pg:/home/gnu/lib/gcrt1.o%s} %{!pg:%{p:/home/gnu/lib/gcrt1.o} %{!p:/home/gnu/lib/crt1.o%s}}} /home/gnu/lib/crti.o%s %{!shared:crtbegin.o%s} %{shared:crtbeginS.o%s}
506 *switches_need_spaces:
510 %{funsigned-char:-D__CHAR_UNSIGNED__}
513 -D__ELF__ -Dunix -Di386 -Dlinux -Asystem(unix) -Asystem(posix) -Acpu(i386) -Amachine(i386)
521 -----------------------------------------------------------------------
523 The above is currently correct for all systems but ix86/Linux.
524 Because of compatibility issues on this platform the dynamic linker
525 must have a different name: ld-linux.so.2. So you have to replace
527 %{!dynamic-linker:-dynamic-linker=/home/gnu/lib/ld.so.1}
529 %{!dynamic-linker:-dynamic-linker=/home/gnu/lib/ld-linux.so.2}
531 in the above example specs file.
533 Future versions of GCC will automatically provide the correct specs.
536 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
537 [Q17] ``Looking through the shared libc file I haven't found the
538 functions `stat', `lstat', `fstat', and `mknod' and while
539 linking on my Linux system I get error messages. How is
540 this supposed to work?''
542 [A17] {RM} Believe it or not, stat and lstat (and fstat, and mknod)
543 are supposed to be undefined references in libc.so.6! Your problem is
544 probably a missing or incorrect /usr/lib/libc.so file; note that this
545 is a small text file now, not a symlink to libc.so.6. It should look
548 GROUP ( libc.so.6 ld.so.1 libc.a )
551 {UD} The Linux ldconfig file probably generates a link libc.so ->
552 libc.so.6 in /lib. This is not correct. There must not be such a
553 link. The linker script with the above contents is placed in
554 /usr/lib which is enough for the linker.
557 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
558 [Q18] ``The prototypes for `connect', `accept', `getsockopt',
559 `setsockopt', `getsockname', `getpeername', `send',
560 `sendto', and `recvfrom' are different in GNU libc from
561 any other system I saw. This is a bug, isn't it?''
563 [A18] {UD} No, this is no bug. This version of the GNU libc already
564 follows the to-be-released POSIX.1g standard. In this standard
565 the type `size_t' is used for all parameters which describe a size.
566 So better change now.
568 This change is critical for system which have
569 sizeof (int) != sizeof (size_t)
573 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
575 Answers were given by:
576 {UD} Ulrich Drepper, <drepper@cygnus.com>
577 {DMT} David Mosberger-Tang, <davidm@AZStarNet.com>
578 {RM} Roland McGrath, <roland@gnu.ai.mit.edu>