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authorUlrich Drepper <drepper@redhat.com>1997-08-10 18:37:15 +0000
committerUlrich Drepper <drepper@redhat.com>1997-08-10 18:37:15 +0000
commit0413b54c02d31cae62e8d13b3ee7ac109ceeff0e (patch)
tree5159587edd2bf4a39fcb5c42588aa35c7350fe8d /manual
parent55c14926be46b12fda4e01d0977911d3b0883db7 (diff)
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1997-08-10 18:48 Ulrich Drepper <drepper@cygnus.com> * Makeconfig: Define build-programs to no if not set and $(config-os) is none. * Makerules (+depfiles): Don't add $(others) if not build-programs. * Rules (others): Don't depend on $(install-bin), $(install-rootbin) and $(install-sbin) if not build-programs. * Makefile (subdirs): Remove login. * sysdeps/mach/hurd/Subdirs: Add login. * sysdeps/unix/Subdirs: Add login. * sysdeps/generic/sys/mman.h: Test feature macros before defining non-POSIX things. Add MAP_FAILED. * sysdeps/unix/bsd/osf/sys/mman.h: Likewise. * sysdeps/unix/bsd/sun/sunos4/sys/mman.h: Likewise. * sysdeps/unix/bsd/ultrix4/sys/mman.h: Likewise. * sysdeps/unix/sysv/irix4/sys/mman.h: Likewise. * sysdeps/unix/sysv/linux/sys/mman.h: Rewrite to not use kernel header but bits/mman.h. Test feature macros before definitions non-POSIX functions. * sysdeps/unix/sysv/linux/alpha/bits/mman.h: New file. * sysdeps/unix/sysv/linux/i386/bits/mman.h: New file. * sysdeps/unix/sysv/linux/m68k/bits/mman.h: New file. * sysdeps/unix/sysv/linux/mips/bits/mman.h: New file. * sysdeps/unix/sysv/linux/powerpc/bits/mman.h: New file. * sysdeps/unix/sysv/linux/sparc/bits/mman.h: New file. * sysdeps/unix/sysv/linux/sparc64/bits/mman.h: New file. * sysdeps/unix/sysv/linux/alpha/Dist: Add bits/mman.h. * sysdeps/unix/sysv/linux/i386/Dist: Likewise. * sysdeps/unix/sysv/linux/m68k/Dist: Likewise. * sysdeps/unix/sysv/linux/mips/Dist: Likewise. * sysdeps/unix/sysv/linux/powerpc/Dist: Likewise. * sysdeps/unix/sysv/linux/sparc/Dist: Likewise. * sysdeps/unix/sysv/linux/sparc64/Dist: New file. Likewise. * catgets/open_catalog.c (__open_catalog): Compare result of mmap with MAP_FAILED and not -1. * elf/dl-load.c (_dl_map_object_from_fd): Likewise. * elf/dl-minimal.c (malloc): Likewise. * elf/dl-misc.c (_dl_sysdep_read_whole_file): Likewise. * locale/loadlocale.c (_nl_load_locale): Likewise. * locale/programs/localedef.c: Likewise. * malloc/malloc.c (mmap_chunk): Likewise. (new_heap): Likewise. * string/stratcliff.c: Likewise. * string/tester.c: Add tests for stpcpy. * gmon/gmon.c (__monstartup): Use calloc instead of malloc+memset. * gmon/sys/gmon.h: Add prototype for write_profiling. * elf/dl-profile.c: Add decsriptions and implement reading of existing data in profiling file. * gmon/sys/gmon_out.h (GMON_SHOBJ_VERSION): New macro for shared lib profiling data. * sysdeps/stub/bits/libc-lock.h (__libc_once_define): Add new first parameter for class. * inet/inet_ntoa.c: Make once control variable static. Correctly handle case where key cannot be retrieved. * inet/Makefile (tests): Add tst-ntoa. * inet/tst-ntoa.c: New file. * manual/time.texi: Document localtime_r, gmtime_r, asctime_r, and ctime_r. Mention that tzname values must not be changed. * manual/users.texi: Document UTMP/WTMP handling functions. Mainly written by Mark Kettenis. * math/libm-test.c (cbrt_test): Add test for number with aboslute value < 1.0. * nss/nss_files/files-XXX.c (internal_setent): If opening of file failed with EGAIN return NSS_STATUS_TRYAGAIN. * nss/nss_files/files-alias.c (internal_setent): Likewise. * sysdeps/generic/bits/utmp.h: Pretty print. * sysdeps/i386/i586/strcpy.S: New file. Much faster implementation. * sysdeps/i386/i586/stpcpy.S: New file. * sysdeps/i386/i686/Implies: Don't fall back on i586 versions since these are less efficient than i486/i386 versions. * sysdeps/libm-i387/e_rem_pio2.c: Add empty file to prevent the version from libm-ieee754 be compiled since the later is not needed. * sysdeps/libm-i387/e_rem_pio2f.c: Likewise. * sysdeps/libm-i387/e_rem_pio2l.c: Likewise. * sysdeps/libm-i387/k_rem_pio2.c: Likewise. * sysdeps/libm-i387/k_rem_pio2f.c: Likewise. * sysdeps/libm-i387/k_rem_pio2l.c: Likewise. * sysdeps/m68k/fpu/e_rem_pio2.c: Likewise. * sysdeps/m68k/fpu/e_rem_pio2f.c: Likewise. * sysdeps/m68k/fpu/e_rem_pio2l.c: Likewise. * sysdeps/m68k/fpu/k_rem_pio2.c: Likewise. * sysdeps/m68k/fpu/k_rem_pio2f.c: Likewise. * sysdeps/m68k/fpu/k_rem_pio2l.c: Likewise. * sysdeps/libm-i387/s_cbrt.S: Fix several bugs. * sysdeps/libm-i387/s_cbrtf.S: Likewise. * sysdeps/libm-i387/s_cbrtl.S: Likewise. * sysdeps/unix/sysv/linux/if_index.c (if_indextoname): Correct little bug. * sysdeps/unix/sysv/linux/bits/socket.h (struct msghdr): Make field msg_iovlen of type int. * time/tzfile.c: Change return type of __tzstring to char *. * time/tzset.c: Likewise. Change definition of __tzstring. * time/tzset.c: Interpret no DST information in user provided time zone specification as it is meant: no DST. Patch by Paul Eggert <eggert@twinsun.com>. 1997-07-20 03:01 Geoff Keating <geoffk@ozemail.com.au> * sysdeps/elf/dl-load.c (add_name_to_object): New procedure. (_dl_map_object_from_fd): Use add_name_to_object. (_dl_map_object): If an object's SONAME is used to resolve a dependency, add it to the list of the object's names. * inet/getnameinfo.c: Make `domain' non-const. * sysdeps/unix/sysv/linux/powerpc/kernel_termios.c: Clean up. * math/test-fenv.c (feenv_nomask_test): Don't execute if FE_NOMASK_ENV is not defined, or if fesetenv(FE_NOMASK_ENV) sets errno to ENOSYS. * sysdeps/powerpc/dl-machine.h: Print proper error message on unknown reloc type (rather than using assert). * sysdeps/unix/sysv/linux/powerpc/profil-counter.h: New file. * sysdeps/unix/sysv/linux/powerpc/profil.c: Deleted. 1997-07-16 12:47 Geoff Keating <geoffk@ozemail.com.au> * sysdeps/powerpc/bits/fenv.h (feraiseexcept): New optimising macro. (feclearexcept): New optimising macro. (FE_NOMASK_ENV): Change to procedure so it can enable exceptions. (FE_ENABLED_ENV): Add. (FE_NONIEEE_ENV): Add. * sysdeps/powerpc/bits/fenv_const.c: Add __fe_enabled_env, __fe_nonieee_env; delete __fe_nomask_env. * sysdeps/powerpc/bits/fe_nomask.c: New file (stub warning until it gets implemented in the kernel). * sysdeps/powerpc/fraiseenv.c: Deal with chips that don't have FE_INVALID_SOFTWARE implemented. Use macros for bit names for clarity. * sysdeps/powerpc/fsetexcptflag.c: Likewise. * io/ftw.c: Don't compare holes in structures. * sysdeps/unix/sysv/linux/sys/sysmacros.h: Cast the result of the macros to `int', because otherwise it might be `long long' which the calling code is probably not expecting. * sysdeps/libm-ieee754/s_lround.c [NO_LONG_DOUBLE]: Fix a few bugs, document the existence of some more. * sysdeps/powerpc/s_llrint.c: New file. * sysdeps/powerpc/s_lrint.c: New file. * sysdeps/powerpc/s_llround.c: New file. * sysdeps/powerpc/s_lround.c: New file. * sysdeps/powerpc/s_sqrt.c: New file. * sysdeps/powerpc/s_sqrtf.c: New file. * sysdeps/powerpc/w_sqrt.s: New empty file. * sysdeps/powerpc/w_sqrtf.s: New empty file. * sysdeps/powerpc/t_sqrt.c: New file. * sysdeps/powerpc/test-arithf.c: New file. * sysdeps/powerpc/Makefile [subdir=math]: Add t_sqrt to support routines. Add test-arithf to test programs. * sysdeps/powerpc/bits/mathdef.h: Add FP_ILOGB0, FP_ILOGBNAN. * sysdeps/powerpc/strcmp.s: Simplify drastically. Now much neater, and possibly faster (or possibly slower, depending on input). 1997-06-08 22:55 Geoff Keating <geoffk@ozemail.com.au> * sysdeps/powerpc/fenvbits.h: Correct FE_DFL_ENV and FE_NOMASK_ENV macros. * sysdeps/powerpc/s_rint.c: New file. 1997-05-22 08:47 Geoff Keating <geoffk@ozemail.com.au> * sysdeps/powerpc/Makefile [subdir=math]: Add q_* routines. * sysdeps/powerpc/Dist: Add quad_float.h. * sysdeps/powerpc/q_dtoq.c: New file. * sysdeps/powerpc/q_itoq.c: New file. * sysdeps/powerpc/q_lltoq.c: New file. * sysdeps/powerpc/q_neg.c: New file. * sysdeps/powerpc/q_qtoi.c: New file. * sysdeps/powerpc/q_qtoll.c: New file. * sysdeps/powerpc/q_qtos.c: New file. * sysdeps/powerpc/q_qtou.c: New file. * sysdeps/powerpc/q_qtoull.c: New file. * sysdeps/powerpc/q_stoq.c: New file. * sysdeps/powerpc/q_ulltoq.c: New file. * sysdeps/powerpc/q_utoq.c: New file. * sysdeps/powerpc/quad_float.h: New file. * sysdeps/powerpc/test-arith.c: New file. * sysdeps/powerpc/fpu_control.h: Fix _FPU_GETCW. * sysdeps/powerpc/fegetround.c: Use mcrfs to be faster and not require a stack frame. * sysdeps/powerpc/bits/fenv.h: Include inline macro for fegetround. 1997-05-18 05:55 Geoff Keating <geoffk@ozemail.com.au> * sysdeps/powerpc/fenv_libc.h (fegetenv_register, fesetenv_register): Add 'volatile'. (set_fpscr_bit, reset_fpscr_bit): New macros, FPSCR_* constants to use with them. * sysdeps/powerpc/s_copysign.S: New file. * sysdeps/powerpc/s_copysignf.s: New file. * sysdeps/powerpc/s_fabs.S: New file. * sysdeps/powerpc/s_fabsf.s: New file. * sysdeps/powerpc/s_isnan.c: New file. * sysdeps/powerpc/s_isnanf.s: New file. * sysdeps/powerpc/s_rintf.c: New file. * sysdeps/powerpc/fenvbits.h: Make FE_INVALID the summary bit in the FPSCR, not the enable bit. * sysdeps/powerpc/fraiseexcpt.c: Consequent change to the above. * sysdeps/powerpc/fclrexcpt.c: Correct. * sysdeps/powerpc/fsetexcptflag.c: Correct. * sysdeps/powerpc/ftestexcpt.c: Is now much simpler. * sysdeps/powerpc/fgetexcptflg.c: Simplify. * sysdeps/powerpc/strlen.s: Schedule better, save 3 clocks :-). * sysdeps/powerpc/dl-machine.h (elf_machine_rela): Add comment explaining some reentrancy issues with lazy PLT entries. 1997-08-09 13:04 Mark Kettenis <kettenis@phys.uva.nl> * login/logout.c (logout): utmpname returns -1 on error. * login/libutil.map: Remove updwtmp. * login/getutline.c: Rename getutline to __getutline and make getutline a weak alias. Make getutxline a weak alias for __getutline. * login/getutid.c: Rename getutid to __getutid and make getutid a weak alias. Make getutxid a weak alias for __getutid. * libc.map: Add getutxid, getutxline. * login/utmpname.c (__utmpname): Reset backend right after backend endutent call. * login/utmp_file.c: Reordered functions. Remove unecessary header files. (getutent_r_file, pututline_file): Do not call setutent_file. At this point the file is guaranteed to be open (assert!). (getutid_r_file, getutline_r_file): Remove check for validity of file descriptor. At this point the file is guaranteed to be open. (getutent_r_file, internal_getut_r, getutline_r_file, pututline_file, updwtmp_file): Do not wait when unlocking file. * login/utmp_daemon.c: General cleanup and a bit of reordering. (getutent_r_daemon, pututline_daemon): Do not call setutent_daemon. At this point the socket is guaranteed to be open (assert!). (getutid_r_daemon, getutline_r_daemon): Do not check if daemon_sock is valid. At this point the socket is guaranteed to be open (assert!). * login/getutline_r.c: Remove unnecessary header files. (__getutline_r): Do not call backend setutent. * login/getutid_r.c: Remove unnecessary header files. (__getutid_r): Do not call backend setutent. * login/getutent_r.c: Remove unneccesary header files. (__libc_utmp_unknown_functions): Added getutid_r_unknown, getutline_r_unknown. (setutent_unknown): Only set file backend if setutent for the file backend was successful. (getutent_r_unknown, pututline_unknown): Call setutent_unknown instead of __setutent. Report failure if no backend was selected. (getutid_r_unknown): New function. (getutline_r_unknown): New function. (__endutent): Reset backend. This makes sure all backends are checked on the next setutent call. 1997-08-08 20:20 Thorsten Kukuk <kukuk@vt.uni-paderborn.de> * nis_cache.c: Replace dummy functions. * libc.map: Add xdr_sizeof symbol. * sunrpc/Makefile: Add xdr_sizeof to routines. * sunrpc/rpc/xdr.h: Add xdr_sizeof prototype. * sunrpc/xdr_sizeof.c: New, from tirpc 2.3. 1997-08-08 Thomas Bushnell, n/BSG <thomas@gnu.ai.mit.edu> * sysdeps/mach/bits/libc-lock.h (__libc_once): Define correctly. 1997-08-07 Thomas Bushnell, n/BSG <thomas@gnu.ai.mit.edu> * sysdeps/mach/hurd/profil.c (fetch_samples): Put parens in the right place. 1997-08-06 Thomas Bushnell, n/BSG <thomas@gnu.ai.mit.edu> * sysdeps/mach/hurd/profil.c (fetch_samples): Do arithmetic on PC's in long long to avoid overflow. 1997-08-07 Thomas Bushnell, n/BSG <thomas@gnu.ai.mit.edu> * sysdeps/mach/bits/libc-lock.h (__libc_once, __libc_once_define): New macros. 1997-08-06 Andreas Jaeger <aj@arthur.rhein-neckar.de> * nis/Makefile (headers): Remove bits/nislib.h. 1997-08-06 14:54 Ulrich Drepper <drepper@cygnus.com> * sysdeps/mach/hurd/Subdirs: Add login. 1997-08-06 14:23 Klaus Espenlaub <kespenla@hydra.informatik.uni-ulm.de> * db/hash/hash.c (init_hash): Don't use stat() if it doesn't provide the preferred block size. * login/programs/database.c (store_state_entry): Don't compile if there is no ut_type field. (store_state_entry, store_process_entry): Use the ut_tv field for timestamps if supported. * login/programs/utmpdump.c (print_entry): Always use ut_tv field. * login/programs/xtmp.c: Fix numerous xtmp/utmp typos. Use the ut_tv field for timestamps if supported. * login/programs/xtmp.h: Fix xtmp/utmp typo. * sysdeps/posix/defs.c (stdstream): Change (PTR) to (void *). * sysdeps/stub/connect.c (connect): Change to __connect, add alias. * sysdeps/stub/send.c (send): Likewise. * sysdeps/stub/s_exp2f.c: Emit correct stub_warning(). * sysdeps/stub/statfs.c: Move stub_warning() to the usual place. * sysdeps/stub/init-first.c: Add definition of __libc_pid. 1997-08-05 13:28 Philip Blundell <pb@spring.nexus.co.uk> * sysdeps/standalone/arm/bits/errno.h: Add EISDIR, EOPNOTSUPP; tidy up formatting. * Makefile (subdirs): Remove `login'. * sysdeps/unix/Subdirs: New file; build `login' subdirectory for Unix systems. 1997-08-05 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/generic/bits/utmpx.h: New file. * sysdeps/mach/hurd/Dist: Add some files. * sysdeps/mips/Dist: Likewise. * sysdeps/mips/mips64/Dist: Likewise. * sysdeps/sparc/Dist: Likewise. * sysdeps/unix/sysv/linux/mips/Dist: Likewise. * sysdeps/unix/sysv/linux/sparc/Dist: Likewise. * sysdeps/mips/mipsel/Dist: New file. * sysdeps/sparc64/elf/Dist: New file. * sysdeps/unix/sysv/linux/sparc64/Dist: New file. 1997-08-05 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * libc.map: Add missing symbols. 1997-08-05 Andreas Jaeger <aj@arthur.rhein-neckar.de> * manual/socket.texi: Correct typos. * manual/math.texi: Correct typos. * manual/time.texi (Formatting Date and Time): Likewise. 1997-08-04 13:06 Thomas Bushnell, n/BSG <thomas@gnu.ai.mit.edu> * gmon/gmon.c (write_gmon): New function; guts from _mcleanup. (_mcleanup): Use write_gmon. (write_profiling): This function can be safely called at any time to write a current histogram without interfering with ongoing profiling. * sysdeps/mach/hurd/profil.c (fetch_samples): Initialize NSAMPLES. 1997-08-01 17:53 Thomas Bushnell, n/BSG <thomas@gnu.ai.mit.edu> * sysdeps/mach/hurd/profil.c (fetch_samples): Sample buffer need not be vm_deallocated; it's a stack buffer. (profil_vm_deallocate): Delete prototype. (#include <../mach/RPC_vm_deallocate_rpc.c>): Drop this inclusion. * sysdeps/mach/hurd/Makefile ($(common-objpfx)hurd/../mach/RPC_vm_deallocate_rpc.c): Delete this rule. * sysdeps/mach/hurd/profil.c (fetch_samples): New function, guts from profile_waiter. (profile_waiter): Use fetch_samples. (profil): When turning off profiling, fetch the last bunch of samples before disabling PC sampling. (fetch_samples): Add prototype. 1997-07-30 12:53 Thomas Bushnell, n/BSG <thomas@gnu.ai.mit.edu> * sysdeps/mach/hurd/Makefile: Give normal rules for the mach RPC source included by profil.c instead of trying to use before-compile grot. 1997-07-23 15:04 Thomas Bushnell, n/BSG <thomas@gnu.ai.mit.edu> * sysdeps/mach/hurd/profil.c (profile_waiter): Do vm_deallocate after releasing lock. Use special RPC stubs and avoid assert, thus making this function entirely independent of the threadvar mechanism and of cthreads. (lock): Convert to be a spin lock instead of a mutex, so that the waiter thread need not use cthreads. Use a fork prepare hook instead of _hurd_fork_locks to make sure we are clean before forking. (fork_profil_child): Renamed from fork_profil. (profil_reply_port): New variable. (profil_vm_deallocate, profil_task_get_sampled_pcs): Special RPC stubs made by special hacks. * sysdeps/mach/hurd/Makefile (before-compile): Add the mach RPC source files that profil.c needs if we are in the gmon directory. * mach/setup-thread.c (__mach_setup_thread): Delete avoidance of a cthreads bug that hasn't existed for two years. * stdio-common/printf_fp.c (__printf_fp): Correct rounding of numbers * locale/programs/locale.c (print_escaped): New function. * time/australasia: Likewise. (open_database, synchronize_database, initialize_database): * nss/nss_files/files-netgrp.c (_nss_netgroup_parseline): Don't * Makerules (load-map-file): Currectly handle missing map file. cannot rely on M_SQRT2 being defined. (log1p): Use __M_SQRT2 not M_SQRT2.
Diffstat (limited to 'manual')
-rw-r--r--manual/math.texi56
-rw-r--r--manual/socket.texi4
-rw-r--r--manual/time.texi72
-rw-r--r--manual/users.texi660
4 files changed, 735 insertions, 57 deletions
diff --git a/manual/math.texi b/manual/math.texi
index d4449bb..71b3651 100644
--- a/manual/math.texi
+++ b/manual/math.texi
@@ -232,7 +232,7 @@ infinite.
@item
Squre root if the operand is less then zero.
@item
-Conversion of an internal floating-point number to an integer or toa
+Conversion of an internal floating-point number to an integer or to a
decimal string when overflow, infinity, or NaN precludes a faithful
representation in that format and this cannot otherwise be signaled.
@item
@@ -247,7 +247,7 @@ If the exception does not cause a trap handler to be called the result
of the operation is taken as a quiet NaN.
@item Division by Zero
-This exception is raised of the devisor is zero and the dividend is a
+This exception is raised if the devisor is zero and the dividend is a
finite nonzero number. If no trap occurs the result is either
@iftex
@tex
@@ -270,8 +270,8 @@ $-\infty$
signs of the operands.
@item Overflow
-This exception is signalled whenever if the result cannot be represented
-as a finite value in the destination precision's format. If no trap
+This exception is signalled whenever the result cannot be represented
+as a finite value in the precision format of the destination. If no trap
occurs the result depends on the sign of the intermediate result and the
current rounding mode (@w{IEEE 754}, @w{section 7.3}):
@enumerate
@@ -334,7 +334,7 @@ $\infty$.
@end enumerate
@item Underflow
-The underflow exception is created when a intermediate result is too
+The underflow exception is created when an intermediate result is too
small for the operation or if the operations result rounded to the
destination precision causes a loss of accuracy by approximating the
result by denormalized numbers.
@@ -342,17 +342,17 @@ result by denormalized numbers.
When no trap is installed for the underflow exception, underflow shall
be signaled (via the underflow flag) only when both tininess and loss of
accuracy have been detected. If no trap handler is installed the
-operation continues witht he inprecise small value or zero if the
+operation continues with an inprecise small value or zero if the
destination precision cannot hold the small exact result.
@item Inexact
-This exception is signaled if the rounded result is not exact (such as
+This exception is signalled if the rounded result is not exact (such as
computing the square root of two) or the result overflows without an
overflow trap.
@end table
To control whether an exception causes a trap to occur all @w{IEEE 754}
-conformant floating-point implementation (either hardware or software)
+conformant floating-point implementations (either hardware or software)
have a control word. By setting specific bits for each exception in
this control word the programmer can decide whether a trap is wanted or
not.
@@ -378,42 +378,42 @@ actual implementation can be very different, depending on the underlying
hardware or software.
To address the single exception the @file{fenv.h} headers defines a
-number macros:
+number of macros:
@vtable @code
@comment fenv.h
@comment ISO
@item FE_INEXACT
-Represent the inexact exception iff the FPU supports this exception.
+Represents the inexact exception iff the FPU supports this exception.
@comment fenv.h
@comment ISO
@item FE_DIVBYZERO
-Represent the divide by zero exception iff the FPU supports this exception.
+Represents the divide by zero exception iff the FPU supports this exception.
@comment fenv.h
@comment ISO
@item FE_UNDERFLOW
-Represent the underflow exception iff the FPU supports this exception.
+Represents the underflow exception iff the FPU supports this exception.
@comment fenv.h
@comment ISO
@item FE_OVERFLOW
-Represent the overflow exception iff the FPU supports this exception.
+Represents the overflow exception iff the FPU supports this exception.
@comment fenv.h
@comment ISO
@item FE_INVALID
-Represent the invalid exception iff the FPU supports this exception.
+Represents the invalid exception iff the FPU supports this exception.
@end vtable
The macro @code{FE_ALL_EXCEPT} is the bitwise OR of all exception macros
which are supported by the FP implementation.
-Each of the supported exception flag can either be set or unset. The
+Each of the supported exception flags can either be set or unset. The
@w{ISO C 9X} standard defines functions to set, unset and test the
status of the flags.
@comment fenv.h
@comment ISO
@deftypefun void feclearexcept (int @var{excepts})
-This functions clears all of the supported exception flags denoted by
+This function clears all of the supported exception flags denoted by
@var{excepts} in the status word.
@end deftypefun
@@ -430,7 +430,7 @@ exception flags indicated by the parameter @var{excepts}.
@end deftypefun
@noindent
-To restore the previously saved values one can use this functions:
+To restore the previously saved values one can use this function:
@comment fenv.h
@comment ISO
@@ -486,7 +486,7 @@ control word for the exceptions and the rounding mode can be safed.
The file @file{fenv.h} defines the type @code{fenv_t}. The layout of a
variable of this type is implementation defined but the variable is able
-to contain the complete status informations. To fill a variable of this
+to contain the complete status information. To fill a variable of this
type one can use this function:
@comment fenv.h
@@ -497,7 +497,7 @@ Store the current floating-point environment in the object pointed to by
@end deftypefun
@noindent
-Another possibility which is useful is several situations is
+Another possibility which is useful in several situations is
@comment fenv.h
@comment ISO
@@ -505,7 +505,7 @@ Another possibility which is useful is several situations is
Store the current floating-point environment in the object pointed to by
@var{envp}. Afterwards, all exception flags are cleared and if
available a mode is installed which continues on all exception and does
-not cause a trap to occur. In ths case a nonzero value is returned.
+not cause a trap to occur. In this case a nonzero value is returned.
If the floating-point implementation does not support such a non-stop
mode, the return value is zero.
@@ -605,14 +605,14 @@ $-\infty$.
Round toward zero.
@end vtable
-At any time one of the four rounding modes above is selected. To get
+At any time one of the above four rounding modes is selected. To get
information about the currently selected mode one can use this function:
@comment fenv.h
@comment ISO
@deftypefun int fegetround (void)
Return the currently selected rounding mode, represented by one of the
-values of the defined rouding mode macros.
+values of the defined rounding mode macros.
@end deftypefun
@noindent
@@ -625,18 +625,18 @@ Change the currently selected rounding mode to the mode described by the
parameter @var{round}. If @var{round} does not correspond to one of the
supported rounding modes nothing is changed.
-The function return a nonzero value iff the requested rounding mode can
+The function returns a nonzero value iff the requested rounding mode can
be established. Otherwise zero is returned.
@end deftypefun
-Changing the rounding mode can be necessary for various reasons. But
+Changing the rounding mode might be necessary for various reasons. But
changing the mode only to round a given number normally is no good idea.
The standard defines a set of functions which can be used to round an
argument according to some rules and for all of the rounding modes there
is a corresponding function.
If a large set of number has to be rounded it might be good to change
-the rounding mode and do not use the function the library provides. So
+the rounding mode and to not use the function the library provides. So
the perhaps necessary switching of the rounding mode in the library
function can be avoided. But since not all rounding modes are
guaranteed to exist on any platform this possible implementation cannot
@@ -684,7 +684,7 @@ The value is the reziprocal of the square root of the value of the number pi.
ALl values are defined as @code{long double} values unless the compiler
does not support this type or @code{__STDC__} is not defined (both is
-unlikey). Historically the numbers were @code{double} values and some
+unlikely). Historically the numbers were @code{double} values and some
old code still relies on this so you might want to add explizit casts if
the extra precision of the @code{long double} value is not needed. One
critical case are functions with a variable number of arguments, such as
@@ -705,7 +705,7 @@ this value is not added to @file{math.h}. Every program should use
@section Floating-Point Comparison Functions
@cindex unordered comparison
-The @w{IEEE 754} standards defines s'a set of functions which allows to
+The @w{IEEE 754} standards defines a set of functions which allows to
compare even those numbers which normally would cause an exception to be
raised since they are unordered. E.g., the expression
@@ -774,7 +774,7 @@ All the macros are defined in a way to ensure that both arguments are
evaluated exactly once and so they can be used exactly like the builtin
operators.
-On several platform these macros are mapped on very efficient functions
+On several platform these macros are mapped to very efficient functions
the processor understands. But on machines missing these functions, the
macros above might be rather slow. So it is best to use the builtin
operators unless it is necessary to use unordered comparisons.
diff --git a/manual/socket.texi b/manual/socket.texi
index 0353eb7..9cb9b43 100644
--- a/manual/socket.texi
+++ b/manual/socket.texi
@@ -142,11 +142,11 @@ But now the POSIX people came and unified the interface with their words
possible.
A solution provides the Unix98 specification which finally introduces a
-type @code{socklen_t}. This type is used in all of the cases in
+type @code{socklen_t}. This type is used in all of the cases that were
previously changed to use @code{size_t}. The only requirement of this
type is that it is an unsigned type of at least 32 bits. Therefore,
implementations which require references to 32 bit variables be passed
-can be as happy as implementations which right from the start of 64 bit
+can be as happy as implementations which use right from the start 64 bit
values.
diff --git a/manual/time.texi b/manual/time.texi
index 1022e1a..d711234 100644
--- a/manual/time.texi
+++ b/manual/time.texi
@@ -536,6 +536,26 @@ Calling @code{localtime} has one other effect: it sets the variable
Zone Functions}.
@end deftypefun
+Using the @code{localtime} function is a big problem in multi-threaded
+programs. The result is returned in a static buffer and this is used in
+all threads. POSIX.1c introduced a varient of this function.
+
+@comment time.h
+@comment POSIX.1c
+@deftypefun {struct tm *} localtime_r (const time_t *@var{time}, struct tm *@var{resultp})
+The @code{localtime_r} function works just like the @code{localtime}
+function. It takes a pointer to a variable containing the calendar time
+and converts it to the broken-down time format.
+
+But the result is not placed in a static buffer. Instead it is placed
+in the object of type @code{struct tm} to which the parameter
+@var{resultp} points.
+
+If the conversion is successful the function returns a pointer to the
+object the result was written into, i.e., it returns @var{resultp}.
+@end deftypefun
+
+
@comment time.h
@comment ISO
@deftypefun {struct tm *} gmtime (const time_t *@var{time})
@@ -547,6 +567,21 @@ Recall that calendar times are @emph{always} expressed in coordinated
universal time.
@end deftypefun
+As for the @code{localtime} function we have the problem that the result
+is placed ina static variable. POSIX.1c also provides a replacement for
+@code{gmtime}.
+
+@comment time.h
+@comment POSIX.1c
+@deftypefun {struct tm *} gmtime_r (const time_t *@var{time}, struct tm *@var{resultp})
+This function is similar to @code{localtime_r}, except that it converts
+just like @code{gmtime} the given time as Coordinated Universal Time.
+
+If the conversion is successful the function returns a pointer to the
+object the result was written into, i.e., it returns @var{resultp}.
+@end deftypefun
+
+
@comment time.h
@comment ISO
@deftypefun time_t mktime (struct tm *@var{brokentime})
@@ -602,6 +637,20 @@ string.)
@end deftypefun
@comment time.h
+@comment POSIX.1c
+@deftypefun {char *} asctime_r (const struct tm *@var{brokentime}, char *@var{buffer})
+This function is similar to @code{asctime} but instead of placing the
+result in a static buffer it writes the string in the buffer pointed to
+by the parameter @var{buffer}. This buffer should have at least room
+for 16 bytes.
+
+If no error occurred the function returns a pointer to the string the
+result was written into, i.e., it returns @var{buffer}. Otherwise
+return @code{NULL}.
+@end deftypefun
+
+
+@comment time.h
@comment ISO
@deftypefun {char *} ctime (const time_t *@var{time})
The @code{ctime} function is similar to @code{asctime}, except that the
@@ -617,6 +666,23 @@ does so. @xref{Time Zone Functions}.
@end deftypefun
@comment time.h
+@comment POSIX.1c
+@deftypefun {char *} ctime_r (const time_t *@var{time}, char *@var{buffer})
+This function is similar to @code{ctime}, only that it places the result
+in the string pointed to by @var{buffer}. It is equivalent to (written
+using gcc extensions, @xref{Statement Exprs,,,gcc,Porting and Using gcc}.):
+
+@smallexample
+(@{ struct tm tm; asctime_r (localtime_r (time, &tm), buf); @})
+@end smallexample
+
+If no error occurred the function returns a pointer to the string the
+result was written into, i.e., it returns @var{buffer}. Otherwise
+return @code{NULL}.
+@end deftypefun
+
+
+@comment time.h
@comment ISO
@comment POSIX.2
@deftypefun size_t strftime (char *@var{s}, size_t @var{size}, const char *@var{template}, const struct tm *@var{brokentime})
@@ -885,7 +951,7 @@ A literal @samp{%} character.
The @var{size} parameter can be used to specify the maximum number of
characters to be stored in the array @var{s}, including the terminating
null character. If the formatted time requires more than @var{size}
-characters, @code{strftime} return zero and the content of the array
+characters, @code{strftime} returns zero and the content of the array
@var{s} is indetermined. Otherwise the return value indicates the
number of characters placed in the array @var{s}, not including the
terminating null character.
@@ -1095,6 +1161,10 @@ GNU programs it is better to use the @code{tm_zone} member of the
broken-down time structure, since @code{tm_zone} reports the correct
abbreviation even when it is not the latest one.
+Though the strings are declared as @code{char *} the user must stay away
+from modifying these strings. Modying the strings will almost certainly
+lead to trouble.
+
@end deftypevar
@comment time.h
diff --git a/manual/users.texi b/manual/users.texi
index a622dd5..ca9dee4 100644
--- a/manual/users.texi
+++ b/manual/users.texi
@@ -42,6 +42,9 @@ can use to examine these databases.
* Who Logged In:: Getting the name of the user who logged in,
or of the real user ID of the current process.
+* User Accounting Database:: Keeping information about users and various
+ actions in databases.
+
* User Database:: Functions and data structures for
accessing the user database.
* Group Database:: Functions and data structures for
@@ -51,7 +54,7 @@ can use to examine these databases.
inquiry functions.
@end menu
-@node User and Group IDs, Process Persona, Users and Groups, Users and Groups
+@node User and Group IDs
@section User and Group IDs
@cindex login name
@@ -72,7 +75,7 @@ not accessible to users who are not a member of that group. Each group
has a @dfn{group name} and @dfn{group ID}. @xref{Group Database},
for how to find information about a group ID or group name.
-@node Process Persona, Why Change Persona, User and Group IDs, Users and Groups
+@node Process Persona
@section The Persona of a Process
@cindex persona
@cindex effective user ID
@@ -114,7 +117,7 @@ its permission to access files, see @ref{Access Permission}.
The user ID of a process also controls permissions for sending signals
using the @code{kill} function. @xref{Signaling Another Process}.
-@node Why Change Persona, How Change Persona, Process Persona, Users and Groups
+@node Why Change Persona
@section Why Change the Persona of a Process?
The most obvious situation where it is necessary for a process to change
@@ -146,7 +149,7 @@ the game program wants to update this file, it can change its effective
user ID to be that for @code{games}. In effect, the program must
adopt the persona of @code{games} so it can write the scores file.
-@node How Change Persona, Reading Persona, Why Change Persona, Users and Groups
+@node How Change Persona
@section How an Application Can Change Persona
@cindex @code{setuid} programs
@@ -177,7 +180,7 @@ when they are not needed, which makes for more robustness.
@c !!! talk about _POSIX_SAVED_IDS
-@node Reading Persona, Setting User ID, How Change Persona, Users and Groups
+@node Reading Persona
@section Reading the Persona of a Process
Here are detailed descriptions of the functions for reading the user and
@@ -262,7 +265,7 @@ read_all_groups (void)
@end smallexample
@end deftypefun
-@node Setting User ID, Setting Groups, Reading Persona, Users and Groups
+@node Setting User ID
@section Setting the User ID
This section describes the functions for altering the user ID (real
@@ -325,7 +328,7 @@ have permission to change to the specified ID.
@end table
@end deftypefun
-@node Setting Groups, Enable/Disable Setuid, Setting User ID, Users and Groups
+@node Setting Groups
@section Setting the Group IDs
This section describes the functions for altering the group IDs (real
@@ -400,7 +403,7 @@ the user name @var{user}. The group ID @var{gid} is also included.
@c groups USER is a member of.
@end deftypefun
-@node Enable/Disable Setuid, Setuid Program Example, Setting Groups, Users and Groups
+@node Enable/Disable Setuid
@section Enabling and Disabling Setuid Access
A typical setuid program does not need its special access all of the
@@ -466,7 +469,7 @@ feature with a preprocessor conditional, like this:
#endif
@end smallexample
-@node Setuid Program Example, Tips for Setuid, Enable/Disable Setuid, Users and Groups
+@node Setuid Program Example
@section Setuid Program Example
Here's an example showing how to set up a program that changes its
@@ -606,7 +609,7 @@ record_score (int score)
@end group
@end smallexample
-@node Tips for Setuid, Who Logged In, Setuid Program Example, Users and Groups
+@node Tips for Setuid
@section Tips for Writing Setuid Programs
It is easy for setuid programs to give the user access that isn't
@@ -650,7 +653,7 @@ would ordinarily have permission to access those files. You can use the
uses the real user and group IDs, rather than the effective IDs.
@end itemize
-@node Who Logged In, User Database, Tips for Setuid, Users and Groups
+@node Who Logged In
@section Identifying Who Logged In
@cindex login name, determining
@cindex user ID, determining
@@ -658,7 +661,9 @@ uses the real user and group IDs, rather than the effective IDs.
You can use the functions listed in this section to determine the login
name of the user who is running a process, and the name of the user who
logged in the current session. See also the function @code{getuid} and
-friends (@pxref{Reading Persona}).
+friends (@pxref{Reading Persona}). How this information is collected by
+the system and how to control/add/remove information from the background
+storage is described in @ref{User Accounting Database}.
The @code{getlogin} function is declared in @file{unistd.h}, while
@code{cuserid} and @code{L_cuserid} are declared in @file{stdio.h}.
@@ -707,7 +712,610 @@ For most purposes, it is more useful to use the environment variable
precisely because the user can set @code{LOGNAME} arbitrarily.
@xref{Standard Environment}.
-@node User Database, Group Database, Who Logged In, Users and Groups
+
+@node User Accounting Database
+@section The User Accounting Database
+@cindex user accounting database
+
+Most Unix-like operating systems keep track of logged in users by
+maintaining a user accounting database. This user accounting database
+stores for each terminal, who has logged on, at what time, the process
+ID of the user's login shell, etc., etc., but also stores information
+about the run level of the system, the time of the last system reboot,
+and possibly more.
+
+The user accounting database typically lives in @file{/etc/utmp},
+@file{/var/adm/utmp} or @file{/var/run/utmp}. However, these files
+should @strong{never} be accessed directly. For reading information
+from and writing information to the user accounting database, the
+functions described in this section should be used.
+
+
+@menu
+* Manipulating the Database:: Scanning and modifying the user
+ accounting database.
+* XPG Functions:: A standardized way for doing the same thing.
+* Logging In and Out:: Functions from BSD that modify the user
+ accounting database.
+@end menu
+
+@node Manipulating the Database
+@subsection Manipulating the User Accounting Database
+
+These functions and the corresponding data structures are declared in
+the header file @file{utmp.h}.
+@pindex utmp.h
+
+@comment utmp.h
+@comment SVID
+@deftp {Data Type} {struct exit_status}
+The @code{exit_status} data structure is used to hold information about
+the exit status of processes marked as @code{DEAD_PROCESS} in the user
+accounting database.
+
+@table @code
+@item short int e_termination
+The exit status of the process.
+
+@item short int e_exit
+The exit status of the process.
+@end table
+@end deftp
+
+@deftp {Data Type} {struct utmp}
+The @code{utmp} data structure is used to hold information about entries
+in the user accounting database. On the GNU system it has the following
+members:
+
+@table @code
+@item short int ut_type
+Specifies the type of login; one of @code{EMPTY}, @code{RUN_LVL},
+@code{BOOT_TIME}, @code{OLD_TIME}, @code{NEW_TIME}, @code{INIT_PROCESS},
+@code{LOGIN_PROCESS}, @code{USER_PROCESS}, @code{DEAD_PROCESS} or
+@code{ACCOUNTING}.
+
+@item pid_t ut_pid
+The process ID number of the login process.
+
+@item char ut_line[]
+The device name of the tty (without @file{/dev/}).
+
+@item char ut_id[]
+The inittab ID of the process.
+
+@item char ut_user[]
+The user's login name.
+
+@item char ut_host[]
+The name of the host from which the user logged in.
+
+@item struct exit_status ut_exit
+The exit status of a process marked as @code{DEAD_PROCESS}.
+
+@item long ut_session
+The Session ID, used for windowing.
+
+@item struct timeval ut_tv
+Time the entry was made. For entries of type @code{OLD_TIME} this is
+the time when the system clock changed, and for entries of type
+@code{NEW_TIME} this is the time the system clock was set to.
+
+@item int32_t ut_addr_v6[4]
+The Internet address of a remote host.
+@end table
+@end deftp
+
+The @code{ut_type}, @code{ut_pid}, @code{ut_id}, @code{ut_tv}, and
+@code{ut_host} fields are not available on all systems. Portable
+applications therefore should be prepared for these situations. To help
+doing this the @file{utmp.h} header provides macros
+@code{_HAVE_UT_TYPE}, @code{_HAVE_UT_PID}, @code{_HAVE_UT_ID},
+@code{_HAVE_UT_TV}, and @code{_HAVE_UT_HOST} if the respective field is
+available. The programmer can handle the situations by using
+@code{#ifdef} in the program code.
+
+The following macros are defined for use as values for the
+@code{ut_type} member of the @code{utmp} structure. The values are
+integer constants.
+
+@table @code
+@comment utmp.h
+@comment SVID
+@vindex EMPTY
+@item EMPTY
+This macro is used to indicate that the entry contains no valid user
+accounting information.
+
+@comment utmp.h
+@comment SVID
+@vindex RUN_LVL
+@item RUN_LVL
+This macro is used to identify the systems runlevel.
+
+@comment utmp.h
+@comment SVID
+@vindex BOOT_TIME
+@item BOOT_TIME
+This macro is used to identify the time of system boot.
+
+@comment utmp.h
+@comment SVID
+@vindex OLD_TIME
+@item OLD_TIME
+This macro is used to identify the time when the system clock changed.
+
+@comment utmp.h
+@comment SVID
+@vindex NEW_TIME
+@item NEW_TIME
+This macro is used to identify the time after the system changed.
+
+@comment utmp.h
+@comment SVID
+@vindex INIT_PROCESS
+@item INIT_PROCESS
+This macro is used to identify a process spawned by the init process.
+
+@comment utmp.h
+@comment SVID
+@vindex LOGIN_PROCESS
+@item LOGIN_PROCESS
+This macro is used to identify the session leader of a logged in user.
+
+@comment utmp.h
+@comment SVID
+@vindex USER_PROCESS
+@item USER_PROCESS
+This macro is used to identify a user process.
+
+@comment utmp.h
+@comment SVID
+@vindex DEAD_PROCESS
+@item DEAD_PROCESS
+This macro is used to identify a terminated process.
+
+@comment utmp.h
+@comment SVID
+@vindex ACCOUNTING
+@item ACCOUNTING
+???
+@end table
+
+The size of the @code{ut_line}, @code{ut_id}, @code{ut_user} and
+@code{ut_host} arrays can be found using the @code{sizeof} operator.
+
+Many older systems have, instead of an @code{ut_tv} member, an
+@code{ut_time} member, usually of type @code{time_t}, for representing
+the time associated with the entry. Therefore, for backwards
+compatibility only, @file{utmp.h} defines @code{ut_time} as an alias for
+@code{ut_tv.tv_sec}.
+
+@comment utmp.h
+@comment SVID
+@deftypefun void setutent (void)
+This function opens the user accounting database to begin scanning it.
+You can then call @code{getutent}, @code{getutid} or @code{getutline} to
+read entries and @code{pututline} to write entries.
+
+If the database is already open, it resets the input to the beginning of
+the database.
+@end deftypefun
+
+@comment utmp.h
+@comment SVID
+@deftypefun {struct utmp *} getutent (void)
+The @code{getutent} function reads the next entry from the user
+accounting database. It returns a pointer to the entry, which is
+statically allocated and may be overwritten by subsequent calls to
+@code{getutent}. You must copy the contents of the structure if you
+wish to save the information or you can use the @code{getutent_r}
+function which stores the data in a user-provided buffer.
+
+A null pointer is returned in case no further entry is available.
+@end deftypefun
+
+@comment utmp.h
+@comment SVID
+@deftypefun void endutent (void)
+This function closes the user accounting database.
+@end deftypefun
+
+@comment utmp.h
+@comment SVID
+@deftypefun {struct utmp *} getutid (const struct utmp *@var{id})
+This function searches forward from the current point in the database
+for an entry that matches @var{id}. If the @code{ut_type} member of the
+@var{id} structure is one of @code{RUN_LVL}, @code{BOOT_TIME},
+@code{OLD_TIME} or @code{NEW_TIME} the entries match if the
+@code{ut_type} members are identical. If the @code{ut_type} member of
+the @var{id} structure is @code{INIT_PROCESS}, @code{LOGIN_PROCESS},
+@code{USER_PROCESS} or @code{DEAD_PROCESS}, the entries match if the the
+@code{ut_type} member of the entry read from the database is one of
+these four, and the @code{ut_id} members match. However if the
+@code{ut_id} member of either the @var{id} structure or the entry read
+from the database is empty it checks if the @code{ut_line} members match
+instead. If a matching entry is found, @code{getutid} returns a pointer
+to the entry, which is statically allocated, and may be overwritten by a
+subsequent call to @code{getutent}, @code{getutid} or @code{getutline}.
+You must copy the contents of the structure if you wish to save the
+information.
+
+A null pointer is returned in case the end of the database is reached
+without a match.
+
+The @code{getutid} function may cache the last read entry. Therefore,
+if you are using @code{getutid} to search for multiple occurrences, it
+is necessary to zero out the static data after each call. Otherwise
+@code{getutid} could just return a pointer to the same entry over and
+over again.
+@end deftypefun
+
+@comment utmp.h
+@comment SVID
+@deftypefun {struct utmp *} getutline (const struct utmp *@var{line})
+This function searches forward from the current point in the database
+until it finds an entry whose @code{ut_type} value is
+@code{LOGIN_PROCESS} or @code{USER_PROCESS}, and whose @code{ut_line}
+member matches the @code{ut_line} member of the @var{line} structure.
+If it finds such an entry, it returns a pointer to the entry which is
+statically allocated, and may be overwritten by a subsequent call to
+@code{getutent}, @code{getutid} or @code{getutline}. You must copy the
+contents of the structure if you wish to save the information.
+
+A null pointer is returned in case the end of the database is reached
+without a match.
+
+The @code{getutline} function may cache the last read entry. Therefore
+if you are using @code{getutline} to search for multiple occurrences, it
+is necessary to zero out the static data after each call. Otherwise
+@code{getutline} could just return a pointer to the same entry over and
+over again.
+@end deftypefun
+
+@comment utmp.h
+@comment SVID
+@deftypefun {struct utmp *} pututline (const struct utmp *@var{utmp})
+The @code{pututline} function inserts the entry @code{*@var{utmp}} at
+the appropriate place in the user accounting database. If it finds that
+it is not already at the correct place in the database, it uses
+@code{getutid} to search for the position to insert the entry, however
+this will not modify the static structure returned by @code{getutent},
+@code{getutid} and @code{getutline}. If this search fails, the entry
+is appended to the database.
+
+The @code{pututline} function returns a pointer to a copy of the entry
+inserted in the user accounting database, or a null pointer if the entry
+could not be added. The following @code{errno} error conditions are
+defined for this function:
+
+@table @code
+@item EPERM
+The process does not have the appropriate privileges; you cannot modify
+the user accounting database.
+@end table
+@end deftypefun
+
+All the @code{get*} functions mentioned before store the information
+they return in a static buffer. This can be a problem in multi-threaded
+programs since the data return for the request is overwritten be the
+return value data in another thread. Therefore the GNU C Library
+provides as extensions three more functions which return the data in a
+user-provided buffer.
+
+@comment utmp.h
+@comment GNU
+@deftypefun int getutent_r (struct utmp *@var{buffer}, struct utmp **@var{result})
+The @code{getutent_r} is equivalent to the @code{getutent} function. It
+returns the next entry from the database. But instead of storing the
+information in a static buffer it stores it in the buffer pointed to by
+the parameter @var{buffer}.
+
+If the call was successful, the function returns @code{0} and the
+pointer variable pointed to by the parameter @var{result} contains a
+pointer to the buffer which contains the result (this is most probably
+the same value as @var{buffer}). If something went wrong during the
+execution of @code{getutent_r} the function returns @code{-1}.
+
+This function is a GNU extension.
+@end deftypefun
+
+@comment utmp.h
+@comment GNU
+@deftypefun int getutid_r (const struct utmp *@var{id}, struct utmp *@var{buffer}, struct utmp **@var{result})
+This function retrieves just like @code{getutid} the next entry matching
+the information stored in @var{id}. But the result is stored in the
+buffer pointed to by the parameter @var{buffer}.
+
+If successful the function returns @code{0} and the pointer variable
+pointed to by the parameter @var{result} contains a pointer to the
+buffer with the result (probably the same as @var{result}. If not
+successful the function return @code{-1}.
+
+This function is a GNU extension.
+@end deftypefun
+
+@comment utmp.h
+@comment GNU
+@deftypefun int getutline_r (const struct utmp *@var{line}, struct utmp *@var{buffer}, struct utmp **@var{result})
+This function retrieves just like @code{getutline} the next entry
+matching the information stored in @var{line}. But the result is stored
+in the buffer pointed to by the parameter @var{buffer}.
+
+If successful the function returns @code{0} and the pointer variable
+pointed to by the parameter @var{result} contains a pointer to the
+buffer with the result (probably the same as @var{result}. If not
+successful the function return @code{-1}.
+
+This function is a GNU extension.
+@end deftypefun
+
+
+In addition to the user accounting database, most systems keep a number
+of similar databases. For example most systems keep a log file with all
+previous logins (usually in @file{/etc/wtmp} or @file{/var/log/wtmp}).
+
+For specifying which database to examine, the following function should
+be used.
+
+@comment utmp.h
+@comment SVID
+@deftypefun int utmpname (const char *@var{file})
+The @code{utmpname} function changes the name of the database to be
+examined to @var{file}, and closes any previously opened database. By
+default @code{getutent}, @code{getutid}, @code{getutline} and
+@code{pututline} read from and write to the user accounting database.
+
+The following macros are defined for use as the @var{file} argument:
+
+@deftypevr Macro {char *} _PATH_UTMP
+This macro is used to specify the user accounting database.
+@end deftypevr
+
+@deftypevr Macro {char *} _PATH_WTMP
+This macro is used to specify the user accounting log file.
+@end deftypevr
+
+The @code{utmpname} function returns a value of @code{0} if the new name
+was successfully stored, and a value of @code{-1} to indicate an error.
+Note that @code{utmpname} does not try open the database, and that
+therefore the return value does not say anything about whether the
+database can be successfully opened.
+@end deftypefun
+
+Specially for maintaining log-like databases the GNU C Library provides
+the following function:
+
+@comment utmp.h
+@comment SVID
+@deftypefun void updwtmp (const char *@var{wtmp_file}, const struct utmp *@var{utmp})
+The @code{updwtmp} function appends the entry *@var{utmp} to the
+database specified by @var{wtmp_file}. For possible values for the
+@var{wtmp_file} argument see the @code{utmpname} function.
+@end deftypefun
+
+@strong{Portability Note:} Although many operating systems provide a
+subset of these functions, they are not standardized. There are often
+subtle differences in the return types, and there are considerable
+differences between the various definitions of @code{struct utmp}. When
+programming for the GNU system, it is probably probably best to stick
+with the functions described in this section. If however, you want your
+program to be portable, consider using the XPG functions described in
+@ref{XPG Functions}, or take a look at the BSD compatible functions in
+@ref{Logging In and Out}.
+
+
+@node XPG Functions
+@subsection XPG User Accounting Database Functions
+
+These functions, described in the X/Open Portability Guide, are declared
+in the header file @file{utmpx.h}.
+@pindex utmpx.h
+
+@deftp {Data Type} {struct utmpx}
+The @code{utmpx} data structure contains at least the following members:
+
+@table @code
+@item short int ut_type
+Specifies the type of login; one of @code{EMPTY}, @code{RUN_LVL},
+@code{BOOT_TIME}, @code{OLD_TIME}, @code{NEW_TIME}, @code{INIT_PROCESS},
+@code{LOGIN_PROCESS}, @code{USER_PROCESS} or @code{DEAD_PROCESS}.
+
+@item pid_t ut_pid
+The process ID number of the login process.
+
+@item char ut_line[]
+The device name of the tty (without @file{/dev/}).
+
+@item char ut_id[]
+The inittab ID of the process.
+
+@item char ut_user[]
+The user's login name.
+
+@item struct timeval ut_tv
+Time the entry was made. For entries of type @code{OLD_TIME} this is
+the time when the system clock changed, and for entries of type
+@code{NEW_TIME} this is the time the system clock was set to.
+@end table
+On the GNU system, @code{struct utmpx} is identical to @code{struct
+utmp} except for the fact that including @file{utmpx.h} does not make
+visible the declaration of @code{struct exit_status}.
+@end deftp
+
+The following macros are defined for use as values for the
+@code{ut_type} member of the @code{utmpx} structure. The values are
+integer constants and are, on the GNU system, identical to the
+definitions in @file{utmp.h}.
+
+@table @code
+@comment utmpx.h
+@comment XPG4.2
+@vindex EMPTY
+@item EMPTY
+This macro is used to indicate that the entry contains no valid user
+accounting information.
+
+@comment utmpx.h
+@comment XPG4.2
+@vindex RUN_LVL
+@item RUN_LVL
+This macro is used to identify the systems runlevel.
+
+@comment utmpx.h
+@comment XPG4.2
+@vindex BOOT_TIME
+@item BOOT_TIME
+This macro is used to identify the time of system boot.
+
+@comment utmpx.h
+@comment XPG4.2
+@vindex OLD_TIME
+@item OLD_TIME
+This macro is used to identify the time when the system clock changed.
+
+@comment utmpx.h
+@comment XPG4.2
+@vindex NEW_TIME
+@item NEW_TIME
+This macro is used to identify the time after the system changed.
+
+@comment utmpx.h
+@comment XPG4.2
+@vindex INIT_PROCESS
+@item INIT_PROCESS
+This macro is used to identify a process spawned by the init process.
+
+@comment utmpx.h
+@comment XPG4.2
+@vindex LOGIN_PROCESS
+@item LOGIN_PROCESS
+This macro is used to identify the session leader of a logged in user.
+
+@comment utmpx.h
+@comment XPG4.2
+@vindex USER_PROCESS
+@item USER_PROCESS
+This macro is used to identify a user process.
+
+@comment utmpx.h
+@comment XPG4.2
+@vindex DEAD_PROCESS
+@item DEAD_PROCESS
+This macro is used to identify a terminated process.
+@end table
+
+The size of the @code{ut_line}, @code{ut_id} and @code{ut_user} arrays
+can be found using the @code{sizeof} operator.
+
+@comment utmpx.h
+@comment XPG4.2
+@deftypefun void setutxent (void)
+This function is similar to @code{setutent}. On the GNU system it is
+simply an alias for @code{setutent}.
+@end deftypefun
+
+@comment utmpx.h
+@comment XPG4.2
+@deftypefun {struct utmpx *} getutxent (void)
+The @code{getutxent} function is similar to @code{getutent}, but returns
+a pointer to a @code{struct utmpx} instead of @code{struct utmp}. On
+the GNU system it simply is an alias for @code{getutent}.
+@end deftypefun
+
+@comment utmpx.h
+@comment XPG4.2
+@deftypefun void endutxent (void)
+This function is similar to @code{endutent}. On the GNU system it is
+simply an alias for @code{endutent}.
+@end deftypefun
+
+@comment utmpx.h
+@comment XPG4.2
+@deftypefun {struct utmpx *} getutxid (const struct utmpx *@var{id})
+This function is similar to @code{getutid}, but uses @code{struct utmpx}
+instead of @code{struct utmp}. On the GNU system it is simply an alias
+for @code{getutid}.
+@end deftypefun
+
+@comment utmpx.h
+@comment XPG4.2
+@deftypefun {struct utmpx *} getutxline (const struct utmpx *@var{line})
+This function is similar to @code{getutid}, but uses @code{struct utmpx}
+instead of @code{struct utmp}. On the GNU system it is simply an alias
+for @code{getutline}.
+@end deftypefun
+
+@comment utmpx.h
+@comment XPG4.2
+@deftypefun {struct utmpx *} pututxline (const struct utmpx *@var{utmp})
+The @code{pututxline} function provides functionality identical to
+@code{pututline}, but uses @code{struct utmpx} instead of @code{struct
+utmp}. On the GNU system @code{pututxline} is simply an alias for
+@code{pututline}.
+@end deftypefun
+
+
+@node Logging In and Out
+@subsection Logging In and Out
+
+These functions, derived from BSD, are available in the separate
+@file{libutil} library, and declared in @file{utmp.h}.
+@pindex utmp.h
+
+Note that the @code{ut_user} member of @code{struct utmp} is called
+@code{ut_name} in BSD. Therefore, @code{ut_name} is defined as an alias
+for @code{ut_user} in @file{utmp.h}.
+
+@comment utmp.h
+@comment BSD
+@deftypefun int login_tty (int @var{filedes})
+This function makes @var{filedes} the controlling terminal of the
+current process, redirects standard input, standard output and
+standard error output to this terminal, and closes @var{filedes}.
+
+This function returns @code{0} on successful completion, and @code{-1}
+on error.
+@end deftypefun
+
+@comment utmp.h
+@comment BSD
+@deftypefun void login (const struct utmp *@var{entry})
+The @code{login} functions inserts an entry into the user accounting
+database. The @code{ut_line} member is set to the name of the terminal
+on standard input. If standard input is not a terminal @code{login}
+uses standard output or standard error output to determine the name of
+the terminal. If @code{struct utmp} has a @code{ut_type} member,
+@code{login} sets it to @code{USER_PROCESS}, and if there is an
+@code{ut_pid} member, it will be set to the process ID of the current
+process. The remaining entries are copied from @var{entry}.
+
+A copy of the entry is written to the user accounting log file.
+@end deftypefun
+
+@comment utmp.h
+@comment BSD
+@deftypefun int logout (const char *@var{ut_line})
+This function modifies the user accounting database to indicate that the
+user on @var{ut_line} has logged out.
+
+The @code{logout} function returns @code{1} if the entry was successfully
+written to the database, or @code{0} on error.
+@end deftypefun
+
+@comment utmp.h
+@comment BSD
+@deftypefun void logwtmp (const char *@var{ut_line}, const char *@var{ut_name}, const char *@var{ut_host})
+The @code{logwtmp} function appends an entry to the user accounting log
+file, for the current time and the information provided in the
+@var{ut_line}, @var{ut_name} and @var{ut_host} arguments.
+@end deftypefun
+
+@strong{Portability Note:} The BSD @code{struct utmp} only has the
+@code{ut_line}, @code{ut_name}, @code{ut_host} and @code{ut_time}
+members. Older systems do not even have the @code{ut_host} member.
+
+
+@node User Database
@section User Database
@cindex user database
@cindex password database
@@ -725,7 +1333,7 @@ network server gives access to it.
* Writing a User Entry:: How a program can rewrite a user's record.
@end menu
-@node User Data Structure, Lookup User, User Database, User Database
+@node User Data Structure
@subsection The Data Structure that Describes a User
The functions and data structures for accessing the system user database
@@ -766,7 +1374,7 @@ be used.
@end table
@end deftp
-@node Lookup User, Scanning All Users, User Data Structure, User Database
+@node Lookup User
@subsection Looking Up One User
@cindex converting user ID to user name
@cindex converting user name to user ID
@@ -839,7 +1447,7 @@ In the later case the global @var{errno} variable is set to
@end deftypefun
-@node Scanning All Users, Writing a User Entry, Lookup User, User Database
+@node Scanning All Users
@subsection Scanning the List of All Users
@cindex scanning the user list
@@ -927,7 +1535,7 @@ This function closes the internal stream used by @code{getpwent} or
@code{getpwent_r}.
@end deftypefun
-@node Writing a User Entry, , Scanning All Users, User Database
+@node Writing a User Entry
@subsection Writing a User Entry
@comment pwd.h
@@ -947,7 +1555,7 @@ would inevitably leave out much of the important information.
The function @code{putpwent} is declared in @file{pwd.h}.
@end deftypefun
-@node Group Database, Netgroup Database, User Database, Users and Groups
+@node Group Database
@section Group Database
@cindex group database
@pindex /etc/group
@@ -963,7 +1571,7 @@ service provides access to it.
* Scanning All Groups:: Scanning the list of all groups.
@end menu
-@node Group Data Structure, Lookup Group, Group Database, Group Database
+@node Group Data Structure
@subsection The Data Structure for a Group
The functions and data structures for accessing the system group
@@ -990,7 +1598,7 @@ null pointer.
@end table
@end deftp
-@node Lookup Group, Scanning All Groups, Group Data Structure, Group Database
+@node Lookup Group
@subsection Looking Up One Group
@cindex converting group name to group ID
@cindex converting group ID to group name
@@ -1061,7 +1669,7 @@ In the later case the global @var{errno} variable is set to
@code{ERANGE}.
@end deftypefun
-@node Scanning All Groups, , Lookup Group, Group Database
+@node Scanning All Groups
@subsection Scanning the List of All Groups
@cindex scanning the group list
@@ -1148,7 +1756,7 @@ This function closes the internal stream used by @code{getgrent} or
@code{getgrent_r}.
@end deftypefun
-@node Netgroup Database, Database Example, Group Database, Users and Groups
+@node Netgroup Database
@section Netgroup Database
@menu
@@ -1158,7 +1766,7 @@ This function closes the internal stream used by @code{getgrent} or
* Netgroup Membership:: How to test for netgroup membership.
@end menu
-@node Netgroup Data, Lookup Netgroup, Netgroup Database, Netgroup Database
+@node Netgroup Data
@subsection Netgroup Data
@cindex Netgroup
@@ -1191,7 +1799,7 @@ case is useful as well. I.e., there may be entries which will not
match any input. For entries like a name consisting of the single
character @code{-} shall be used.
-@node Lookup Netgroup, Netgroup Membership, Netgroup Data, Netgroup Database
+@node Lookup Netgroup
@subsection Looking up one Netgroup
The lookup functions for netgroups are a bit different to all other
@@ -1262,7 +1870,7 @@ selected netgroup. As a result all string pointers returned by calls
to @code{getnetgrent} are invalid afterwards.
@end deftypefun
-@node Netgroup Membership, , Lookup Netgroup, Netgroup Database
+@node Netgroup Membership
@subsection Testing for Netgroup Membership
It is often not necessary to scan the whole netgroup since often the
@@ -1295,7 +1903,7 @@ itself is not found, the netgroup does not contain the triple or
internal errors occurred.
@end deftypefun
-@node Database Example, , Netgroup Database, Users and Groups
+@node Database Example
@section User and Group Database Example
Here is an example program showing the use of the system database inquiry