From 55c14926be46b12fda4e01d0977911d3b0883db7 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Mon, 4 Aug 1997 14:31:26 +0000 Subject: Update. 1997-08-04 15:29 Ulrich Drepper * locale/programs/localedef.c (main): Set bit in avail for those categories which are successfully read. * locale/programs/locfile.c (check_all_categories): Don't check categories if they are not available. (write_all_categories): Don't write categories if they are not available. * login/setutent_r.c (setutent_unknown): Change return type to int and return result of called function. * manual/arith.texi: Mark floating-point test macro from ISO C 9X as macros (not functions). * manual/libc.texinfo (UPDATED): Update. * manual/math.texi: Document exceptions, functions to handle exceptions, mathematical constants, FP comparison functions and several new functions from ISO C 9X. Change parameter of drand48, lrand48, and mrand48 to void (not empty). * manual/pattern.texi: Remove paragraph which explained that wordexp is executed by running a shell. * manual/time.texi: Explain difficulties with strftime if the functions returns 0 and no error occurred. * math/math.h: Correct comment for some M_* constants. (isgreater, isgreaterequal, isless, islessequal, islessgreater, inunordered): Rewrite to make sure the arguments are evaluated exactly once. * nis/rpcsvc/nis.x: Undo last change. * nis/rpcsvc/nis.h: Likewise. * nis/rpcsvc/nislib.h: File moved back to here. * posix/sys/types.h: Don't define socklen_t. Pretty print. * socket/sys/socket.h (bind, getsockname, connect, sendto, recvfrom, getsockopt, setsockopt, accept): Change size argument to type socklen_t. Pretty print. * manual/socket.texi: Describe socklen_t and change prototypes of socket functions to use socklen_t. * sysdeps/generic/bits/socket.h: Define socklen_t. (struct msghdr): Correct types to use socklen_t. * sysdeps/unix/sysv/linux/bits/socket.h: Likewise. * sysdeps/unix/sysv/linux/mips/bits/socket.h: Likewise. * stdio-common/printf_fp.c (__printf_fp): Correct rouding of number 1.0 < x < 8.0. * stdio-common/tfformat.c: Add new tests for above bug. * stdlib/strtod.c: Fix typo. * string/Makefile (headers): Add bits/string.h. (CFLAGS-*): Add -D__NO_STRING_INLINES. * string/string.h: Include if optimizing and __NO_STRING_INLINES is not defined. * sysdeps/stub/bits/string.h: New file. * sysdeps/powerpc/bits/fenv.h: Fix typos. * sysdeps/unix/sysv/linux/if_index.c: Let functions return ENOSYS if SIOGIFINDEX is not defined. * sysdeps/wordsize-32/inttypes.h: Pretty print. * sysdeps/wordsize-64/inttypes.h: Pretty print. * termios/cfsetspeed.c: Rewrite loop to do what it shall do. * wcsmbs/Makefile (tests): Add tst-wcstof. * wcsmbs/tst-wcstof.c: New file. 1997-08-01 Andreas Schwab * sysdeps/m68k/__longjmp.c: Replace call to abort by infinite loop, to avoid dragging stdio into the dynamic linker. 1997-08-02 19:44 H.J. Lu * nis/nis_findserv.c (xid, xid_seed, xid_lookup): Make them u_int32_t. 1997-08-03 Andreas Jaeger * posix/wordexp.c (parse_tilde): Fix calls to __getpwnam_r and __getpwuid_r. Include to get prototypes of *printf. (exec_comm): Remove unneeded variable *sh. * libc.map: Add wordexp, wordfree. * posix/Makefile (routines): Add wordexp. 1997-08-03 Andreas Jaeger * posix/wordexp.c: Correct typo in comment. (wordexp): Likewise. * manual/errno.texi (Error Codes): Fix typo. 1997-08-03 15:28 Ulrich Drepper * csu/initfini.c (SECTION): Don't put quotes around section name since this is not understood by all assemblers. Patch by Klaus Espenlaub . --- manual/time.texi | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) (limited to 'manual/time.texi') diff --git a/manual/time.texi b/manual/time.texi index d0b0e0a111..1022e1a41f 100644 --- a/manual/time.texi +++ b/manual/time.texi @@ -885,11 +885,30 @@ 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, the excess characters are discarded. The return value from -@code{strftime} is the number of characters placed in the array @var{s}, -not including the terminating null character. If the value equals -@var{size}, it means that the array @var{s} was too small; you should -repeat the call, providing a bigger array. +characters, @code{strftime} return 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. + +@emph{Warning:} This convention for the return value which is prescribed +in @w{ISO C} can lead to problems in some situations. For certain +format strings and certain locales the output really can be the empty +string and this cannot be discovered by testing the return value only. +E.g., in most locales the AM/PM time format is not supported (most of +the world uses the 24 hour time representation). In such locales +@code{"%p"} will return the empty string, i.e., the return value is +zero. To detect situations like this something similar to the following +code should be used: + +@smallexample +buf[0] = '\1'; +len = strftime (buf, bufsize, format, tp); +if (len == 0 && buf[0] != '\0') + @{ + /* Something went wrong in the strftime call. */ + @dots{} + @} +@end smallexample If @var{s} is a null pointer, @code{strftime} does not actually write anything, but instead returns the number of characters it would have written. -- cgit 1.4.1