Mercurial > hg > octave-lyh > gnulib-hg
changeset 8789:9bd078338b2f
Redundant through doc/functions/*.texi.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Tue, 01 May 2007 22:32:06 +0000 |
parents | a6de3a541ad4 |
children | d4e45bf490d3 |
files | ChangeLog doc/functions.texi |
diffstat | 2 files changed, 5 insertions(+), 889 deletions(-) [+] |
line wrap: on
line diff
--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2007-05-01 Bruno Haible <bruno@clisp.org> + + * doc/functions.texi: Remove file, now redundant through + doc/functions/*.texi. + 2007-05-01 Bruno Haible <bruno@clisp.org> * modules/argp (Depends-on): Add sleep.
deleted file mode 100644 --- a/doc/functions.texi +++ /dev/null @@ -1,889 +0,0 @@ -@node Function Portability -@section Portability of Standard Functions -@cindex functions - -@c Copyright (C) 2006 Free Software Foundation, Inc. - -@c Permission is granted to copy, distribute and/or modify this document -@c under the terms of the GNU Free Documentation License, Version 1.2 or -@c any later version published by the Free Software Foundation; with no -@c Invariant Sections, with no Front-Cover Texts, and with no Back-Cover -@c Texts. A copy of the license is included in the ``GNU Free -@c Documentation License'' file as part of this distribution. - -Many standard library functions have portability limitations, although -they are specified in the -@uref{http://www.opengroup.org/susv3, Posix standard}. In this section, -we mention only functions that behave differently than specified; we don't -mention functions that are not implemented at all on some platforms, or -that are implemented but not declared on some platforms. Many of the -portability problems have a solution in @ref{Gnulib}. - -@table @code -@item a64l -This function was not correctly implemented in glibc versions before 2.2.5. - -@item accept -Some systems don't have a @code{socklen_t} type; in this case this function's -third argument type is @samp{int *}. - -@item asctime -This function may overflow its internal buffer if an invalid year is passed. - -@item asctime_r -This function may put more than 26 bytes into the argument buffer if an -invalid year is passed. - -@item basename -glibc has two different functions @code{basename}: the POSIX version and -the GNU version. - -@code{basename} assumes file names in POSIX syntax; it does not work with file -names in Windows syntax. - -@item bcmp -This function is marked as ``legacy'' in POSIX. Better use @code{memcmp} -instead. - -@item bcopy -This function is marked as ``legacy'' in POSIX. Better use @code{memcpy} -or @code{memmove} instead. - -@item btowc -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item bzero -This function is marked as ``legacy'' in POSIX. Better use @code{memset} -instead. - -@item chown -When applied to a symbolic link, some implementations don't dereference -the symlink, i.e.@: they behave like @code{lchown}. - -@item cproj -@itemx cprojf -@itemx cprojl -The glibc implementation is or was broken. - -@item creat -On Windows, this function returns a file handle in @code{O_TEXT} mode. If you -need a file handle in @code{O_BINARY} mode, you need to use the function -@code{open} instead. - -On platforms where @code{off_t} is a 32-bit type, @code{creat} may not work -correctly to create files larger than 2 GB. The fix is to use the -@code{AC_SYS_LARGEFILE} macro. - -@item ctime -This function may overflow its internal buffer if an invalid year is passed. - -@item ctime_r -This function may put more than 26 bytes into the argument buffer if an -invalid year is passed. - -@item dirname -@code{dirname} assumes file names in POSIX syntax; it does not work with file -names in Windows syntax. - -@item dlopen -If the file name argument is not absolute, the file is searched for. The -search algorithm is system specific. - -@item dlsym -The visibility of symbols loaded in dependent shared libraries or present -in the main executable is system dependent. - -@item ecvt -This function is marked as ``legacy'' in POSIX. Better use @code{sprintf} -instead. - -@item errno -On Windows, the socket functions don't set @code{errno}; their error code is -available through @code{WSAGetLastError()} instead. - -@item fclose -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -@item fcvt -This function is marked as ``legacy'' in POSIX. Better use @code{sprintf} -instead. - -@item fdopen -@itemx fflush -On Windows systems (excluding Cygwin), these functions do not set @code{errno} -upon failure. - -@item fgetc -@itemx fgets -On Windows systems (excluding Cygwin), these functions do not set @code{errno} -upon failure. - -@item fgetwc -@itemx fgetws -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item fnmatch -This function is broken in some version of Solaris or glibc. - -@item fopen -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -On Windows, this function returns a file stream in ``text'' mode by default; -this means that it translates @code{'\n'} to CR/LF by default. Use the -@code{"b"} flag if you need reliable binary I/O. - -@item fork -On some systems, @code{fork} followed by a call of the @code{exec} family -(@code{execl}, @code{execlp}, @code{execle}, @code{execv}, @code{execvp}, -or @code{execve}) is less efficient than @code{vfork} followed by the same -call. @code{vfork} is a variant of @code{fork} that has been introduced to -optimize the @code{fork}/@code{exec} pattern. - -On Windows systems (excluding Cygwin), this function is not implemented; use -@code{spawnvp} instead. - -@item fprintf -On NetBSD and Windows, this function doesn't support format directives that -access arguments in an arbitrary order, such as @code{"%2$s"}. The fix is to -include @file{<libintl.h>} from GNU gettext; it redefines this function so that -it is POSIX compliant. - -On Windows systems (excluding Cygwin), this function doesn't support -the @code{'} flag and the @code{hh}, @code{ll}, @code{j}, @code{t}, -@code{z} size specifiers. - -@item fputc -@itemx fputs -On Windows systems (excluding Cygwin), these functions do not set @code{errno} -upon failure. - -@item fputwc -@itemx fputws -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item fread -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -@item free -On old systems, @code{free (NULL)} is not allowed. - -@item freopen -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -@item fscanf -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -On Windows, this function doesn't support the @code{hh}, @code{ll}, @code{j}, -@code{t}, @code{z} size specifiers. - -@item fseek -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -@item fstat -On platforms where @code{off_t} is a 32-bit type, @code{stat} may not correctly -report the size of files or block devices larger than 2 GB. The fix is to -use the @code{AC_SYS_LARGEFILE} macro. - -On Cygwin, @code{fstat} applied to the file descriptors 0 and 1, returns -different @code{st_ino} values, even if standard input and standard output -are not redirected and refer to the same terminal. - -@item ftime -This function is marked as ``legacy'' in POSIX. Better use @code{gettimeofday} -or @code{clock_gettime} instead, and use @code{ftime} only as a fallback for -portability to Windows systems. - -@item fwide -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@code{fwide} is not guaranteed to be able to change a file stream's mode -to a different mode than the current one. - -@item fwprintf -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item fwrite -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -@item fwscanf -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item gcvt -This function is marked as ``legacy'' in POSIX. Better use @code{sprintf} -instead. - -@item getaddrinfo -On Windows, this function is declared in @code{<ws2tcpip.h>} rather than in -@code{<netdb.h>}. - -@item getc -@itemx getchar -On Windows systems (excluding Cygwin), these functions do not set @code{errno} -upon failure. - -@item getcwd -On glibc systems, @code{getcwd (NULL, n)} allocates memory for the result. -On other systems, this call is not allowed. - -@item getgroups -On Ultrix 4.3, @code{getgroups (0, 0)} always fails. See macro -@samp{AC_FUNC_GETGROUPS}. - -@item gethostname -If the given buffer is too small for the host name, some implementations -fail with @code{EINVAL}, instead of returning a truncated host name. - -@item getopt -The default behavior of the glibc implementation of @code{getopt} allows -mixing option and non-option arguments on the command line in any order. -Other implementations, such as the one in Cygwin, enforce strict POSIX -compliance: they require that the option arguments precede the non-option -arguments. This is something to watch out in your program's testsuite. - -@item getpeername -Some systems don't have a @code{socklen_t} type; in this case this function's -third argument type is @samp{int *}. - -@item getrusage -Many systems don't fill in all the fields of @code{struct rusage} with -meaningful values. - -@item gets -This function should never be used, because it can overflow any given buffer. - -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -@item getsockname -Some systems don't have a @code{socklen_t} type; in this case this function's -third argument type is @samp{int *}. - -@item getsockopt -Some systems don't have a @code{socklen_t} type; in this case this function's -fifth argument type is @samp{int *}. - -Many socket options are not available on all systems. - -BeOS has the @code{setsockopt} function, but not the @code{getsockopt} -function. - -@item gettimeofday -On some systems, @code{gettimeofday} clobbers the buffer in which -@code{localtime} returns its result. - -@item getwc -@itemx getwchar -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item getwd -The size of the buffer required for this function is not a compile-time -constant. Also, the function truncates a result that would be larger than -the minimum buffer size. For these reasons, this function is marked as -``legacy'' in POSIX. Better use the @code{getcwd} function instead. - -@item glob -Some systems may store additional flags in the @code{gl_flags} field. - -@item gmtime_r -Some systems define a function of this name that is incompatible to POSIX. - -@item iconv -This function was not correctly implemented in glibc versions before 2.2. - -When @code{iconv} encounters an input character that is valid but that can -not be converted to the output character set, glibc's and GNU libiconv's -@code{iconv} stop the conversion. Some other implementations put an -implementation-defined character into the output buffer. - -@item iconv_open -The set of supported encodings and conversions is system dependent. - -@item index -This function is marked as ``legacy'' in POSIX. Better use @code{strchr} -instead. - -@item inet_addr -On some old systems, this function returns a @samp{struct in_addr} rather -than a scalar type such as @samp{unsigned int} or @samp{unsigned long}. - -@item ioctl -Most @code{ioctl} requests are platform and hardware specific. - -@item isatty -On Windows, @code{isatty} also returns true for character devices such as -@file{NUL}. - -@item iswalnum -@itemx iswalpha -@itemx iswblank -@itemx iswcntrl -@itemx iswctype -@itemx iswdigit -@itemx iswgraph -@itemx iswlower -@itemx iswprint -@itemx iswpunct -@itemx iswspace -@itemx iswupper -@itemx iswxdigit -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item l64a -This function was not correctly implemented in glibc versions before 2.2.5. - -@item localtime_r -Some systems define a function of this name that is incompatible to POSIX. - -@item longjmp -The effects of this call are system and compiler optimization dependent, -since it restores the contents of register-allocated variables but not -the contents of stack-allocated variables. - -When longjumping out of a signal handler that was being executed on an -alternate stack (installed through @code{sigaltstack}), on FreeBSD, NetBSD, -OpenBSD, you need to clear the @code{SS_ONSTACK} flag in the @code{stack_t} -structure managed by the kernel. - -@item lseek -POSIX does not specify which file descriptors support seeking and which don't. -In practice, regular files and block devices support seeking, and ttys, pipes, -and most character devices don't support it. - -On platforms where @code{off_t} is a 32-bit type, @code{lseek} does not work -correctly with files larger than 2 GB. The fix is to use the -@code{AC_SYS_LARGEFILE} macro. - -@item lstat -When the argument ends in a slash, some systems don't dereference the -argument. - -On platforms where @code{off_t} is a 32-bit type, @code{lstat} may not -correctly report the size of files or block devices larger than 2 GB. The fix -is to use the @code{AC_SYS_LARGEFILE} macro. - -On Windows systems (excluding Cygwin), symlinks are not supported, so -@code{lstat} does not exist. The fix is to define lstat to use stat. - -@item mbrtowc -@itemx mbsrtowcs -@itemx mbstowcs -@itemx mbtowc -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item mkdir -When the argument ends in a slash, the function call fails on some systems. - -On Windows systems (excluding Cygwin), this function is called @code{_mkdir} -and takes only one argument. The fix is to define a macro like this: -@smallexample -#define mkdir ((int (*)()) _mkdir) -@end smallexample -or -@smallexample -#define mkdir(path,mode) _mkdir (path) -@end smallexample - -@item mkstemp -On some systems (HP-UX 10.20, SunOS 4.1.4, Solaris 2.5.1), mkstemp has a silly -limit that it can create no more than 26 files from a given template. On -OSF/1 4.0f, it can create only 32 files per process. - -On systems other than glibc 2.0.7 or newer, @code{mkstemp} can create a -world or group writable or readable file, if you haven't set the process -umask to 077. This is a security risk. - -@item mktemp -This function is not appropriate for creating temporary files. (It has -security risks.) Therefore it is marked as ``legacy'' in POSIX. Better use -@code{mkstemp} instead. - -@item mktime -Some implementations of @code{mktime} may go into an endless loop. - -@item mmap -To get anonymous memory, on some systems, you can use the flags -@code{MAP_ANONYMOUS | MAP_PRIVATE} and @code{-1} instead of a file descriptor; -on others you have to use a read-only file descriptor of @file{/dev/zero}. - -On HP-UX, passing a non-NULL first argument, as a hint for the address (even -without @code{MAP_FIXED}, often causes @code{mmap} to fail. Better pass NULL -in this case. - -On HP-UX, @code{MAP_FIXED} basically never works. On other systems, it depends -on the circumstances whether memory can be returned at a given address. - -@item mprotect -On AIX, it is not possible to use @code{mprotect} on memory regions allocated -with @code{malloc}. - -@item msync -On NetBSD, @code{msync} takes only two arguments. - -@item nanosleep - -@item nice -In glibc before glibc 2.2.4, @code{nice} returned 0 upon success. - -@item nl_langinfo -Some older versions of glibc had @code{nl_langinfo} but not the @code{CODESET} -macro. - -On Cygwin, which doesn't have locales, @code{nl_langinfo(CODESET)} always -returns @code{"US-ASCII"}. - -@item open -On Windows, this function returns a file handle in @code{O_TEXT} mode by -default; this means that it translates '\n' to CR/LF by default. Use the -@code{O_BINARY} flag if you need reliable binary I/O. - -On platforms where @code{off_t} is a 32-bit type, @code{open} may not work -correctly with files larger than 2 GB. The fix is to use the -@code{AC_SYS_LARGEFILE} macro. - -@item poll -On MacOS X 10.4.0 and AIX 5.3, this function doesn't work on special files -like @file{/dev/null} and ttys like @file{/dev/tty}. - -@item printf -On NetBSD and Windows, this function doesn't support format directives that -access arguments in an arbitrary order, such as @code{"%2$s"}. The fix is to -include @file{<libintl.h>} from GNU gettext; it redefines this function so that -it is POSIX compliant. - -On Windows systems (excluding Cygwin), this function doesn't support -the @code{'} flag and the @code{hh}, @code{ll}, @code{j}, @code{t}, -@code{z} size specifiers. - -@item pthread_create -On Linux/glibc systems before the advent of NPTL, signals could only be -sent to one particular thread. In POSIX, signals are sent to the entire -process and executed by any thread of the process that happens to have the -particular signal currently unblocked. - -@item putc -@itemx putchar -@itemx puts -On Windows systems (excluding Cygwin), these functions do not set @code{errno} -upon failure. - -@item putwc -@itemx putwchar -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item readlink -When @code{readlink} is called on a directory: In the case of NFS mounted -directories, Cygwin sets @code{errno} to @code{ENOENT} or @code{EIO} instead of -@code{EINVAL}. To avoid this problem, check for a directory before calling -@code{readlink}. - -When @code{readlink} is called on a file that is not a symbolic link: -Irix may set @code{errno} to @code{ENXIO} instead of @code{EINVAL}. Cygwin -may set errno to @code{EACCES} instead of {EINVAL}. - -@item realpath -This function does not allow to determine the required size of output buffer; -PATH_MAX --- if it is defined --- is nothing more than a guess. - -@item recvfrom -Some systems don't have a @code{socklen_t} type; in this case this function's -sixth argument type is @samp{int *}. - -@item regcomp -@itemx regexec -Many regular expression implementations have bugs. - -@item rename -This function does not work on SunOS 4.1 when the source file name ends in a -slash. - -@item rewind -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -@item rindex -This function is marked as ``legacy'' in POSIX. Better use @code{strrchr} -instead. - -@item rmdir -When @code{rmdir} fails because the specified directory is not empty, the -@code{errno} value is system dependent. - -@item scanf -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -On Windows, this function doesn't support the @code{hh}, @code{ll}, @code{j}, -@code{t}, @code{z} size specifiers. - -@item select -When you call @code{select} with a timeout, some implementations modify the -timeout parameter so that upon return from the function, it contains the -amount of time not slept. Other implementations leave the timeout parameter -unmodified. - -On Windows systems (excluding Cygwin) and on BeOS, @code{select} can only be -called on descriptors created by the @code{socket} function, not on regular -file descriptors. - -On Linux, when some file descriptor refers to a regular file, @code{select} -may fail, setting @code{errno} to @code{EBADF}. - -@item setcontext -The effects of this call are system and compiler optimization dependent, -since it restores the contents of register-allocated variables but not -the contents of stack-allocated variables. - -@item setenv -In some versions of glibc (e.g.@: 2.3.3), @code{setenv} doesn't fail if the -first argument contains a @samp{=} character. - -@item setjmp -POSIX does not specify whether @code{setjmp} saves the signal mask in the -@code{jmp_buf}. It does on BSD systems, and on glibc systems when -@code{_BSD_SOURCE} is defined; in this case @code{setjmp} behaves like -@code{sigsetjmp}, and functions @code{_setjmp} and @code{_longjmp} are -available that don't save or restore the signal mask. On System V systems, -and on glibc systems by default, @code{setjmp} doesn't save the signal mask. - -@item setlocale -On Cygwin, which doesn't have locales, @code{setlocale(LC_ALL,NULL)} always -returns @code{"C"}. - -@item setsockopt -Many socket options are not available on all systems. - -@item setvbuf -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -@item shmat -Attempts to @code{shmat} into a previously malloc-ed region fail on SunOS 4, -with @code{errno} set to @code{EINVAL}, even if there is an @code{munmap} call -in between. - -On Linux, the flag @code{SHM_REMAP} is needed in order to force @code{shmat} -to replace existing memory mappings in the specify address range. On other -systems, it is not needed. - -@item shmget -On many systems (not Linux), SHMMAX is so small that it is unusable for -reasonable applications, and/or @code{shmget} requires superuser privileges. - -@item sigaction -The symbolic value @code{SIG_IGN} for the @code{SIGCHLD} signal is equivalent -to a signal handler -@smallexample -void handle_child (int sigchld) -@{ - while (waitpid (-1, NULL, WNOHANG) > 0) - ; -@} -@end smallexample -except that @code{SIG_IGN} for @code{SIGCHLD} has the effect that the children -execution times are not accounted in the @code{times} function. -On some systems (BSD? SystemV? Linux?), you need to use the @code{sigaction} -flag @code{SA_NOCLDWAIT} in order to obtain this behavior. - -@item sigaltstack -@code{sigaltstack} doesn't work on HP-UX 11/IA-64 and OpenBSD 3.6/Sparc64. - -@item signal -On System V systems, when the signal is triggered, the kernel uninstalls the -handler (i.e.@: resets the signal's action to SIG_DFL) before invoking the -handler. This opens the door to race conditions: undesired things happen -if the signal is triggered twice and the signal handler was not quick enough -reinstalling itself as a handler. On BSD systems and glibc systems, on the -other hand, when the signal is triggered, the kernel blocks the signal -before invoking the handler. This is saner, but POSIX still allows either -behavior. To avoid this problem, use @code{sigaction} instead of -@code{signal}. - -@item sigtimedwait -Linux implements the meaning of NULL timeout by doing what @code{sigwaitinfo} -does; other systems may not do the same. - -@item sigwait -On Linux/glibc systems before the advent of NPTL, signals could only be -sent to one particular thread. In POSIX, signals are sent to the entire -process and executed by any thread of the process that happens to have the -particular signal currently unblocked. - -@item sleep -According to POSIX, the @code{sleep} function may interfere with the program's -use of the @code{SIGALRM} signal. On Linux, it doesn't; on other platforms, -it may. - -@item snprintf -On NetBSD and Windows, this function doesn't support format directives that -access arguments in an arbitrary order, such as @code{"%2$s"}. The fix is to -include @file{<libintl.h>} from GNU gettext; it redefines this function so that -it is POSIX compliant. - -On Windows systems (excluding Cygwin), this function doesn't support -the @code{'} flag and the @code{hh}, @code{ll}, @code{j}, @code{t}, -@code{z} size specifiers. - -@item socket -On BeOS, the descriptors returned by the @code{socket} function can not be used -in calls to @code{read}, @code{write}, and @code{close}; you have to use -@code{recv}, @code{send}, @code{closesocket} in these cases instead. - -@item sprintf -On NetBSD and Windows, this function doesn't support format directives that -access arguments in an arbitrary order, such as @code{"%2$s"}. The fix is to -include @file{<libintl.h>} from GNU gettext; it redefines this function so that -it is POSIX compliant. - -On Windows systems (excluding Cygwin), this function doesn't support -the @code{'} flag and the @code{hh}, @code{ll}, @code{j}, @code{t}, -@code{z} size specifiers. - -@item sscanf -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -On Windows, this function doesn't support the @code{hh}, @code{ll}, @code{j}, -@code{t}, @code{z} size specifiers. - -@item stat -On platforms where @code{off_t} is a 32-bit type, @code{stat} may not correctly -report the size of files or block devices larger than 2 GB. The fix is to -use the @code{AC_SYS_LARGEFILE} macro. - -Cygwin's @code{stat} function sometimes sets @code{errno} to @code{EACCES} when -@code{ENOENT} would be more appropriate. - -@item strcasecmp -@itemx strcasestr -As of 2006, no system is known that implements these functions correctly in -multibyte locales. - -@item strerror_r -glibc has an incompatible version of this function. The POSIX compliant code -@smallexample -char *s = (strerror_r (err, buf, buflen) == 0 ? buf : NULL); -@end smallexample -is essentially equivalent to this code using the glibc function: -@smallexample -char *s = strerror_r (err, buf, buflen); -@end smallexample - -@item strstr -As of 2006, no system is known that implements this function correctly in -multibyte locales. - -@item swprintf -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -On Windows, this function does not take a buffer size as second argument. - -@item system -On Windows systems (excluding Cygwin), the command processor used by the -@code{system} function is @file{cmd.exe}, not @file{/bin/sh}. Accordingly, -the rules for quoting shell arguments containing spaces, quote or other special -characters are different. - -@item tcdrain -On some systems, @code{tcdrain} on a non-tty fails with @code{errno} set to -@code{EINVAL} or, on MacOS X, also @code{EOPNOTSUPP} or @code{ENODEV}, rather -than @code{ENOTTY}. - -@item tcflush -On some systems, @code{tcflush} of @code{TCIFLUSH} on a non-tty fails with -errno set to @code{EINVAL} rather than @code{ENOTTY}. - -On some systems, @code{tcflush} of @code{TCOFLUSH} on a non-tty fails with -errno set to @code{EINVAL} or, on IRIX, also @code{ENOSYS}, or, on MacOS X, -also @code{EOPNOTSUPP} or @code{ENODEV}, rather than @code{ENOTTY}. - -@item tempnam -This function is not appropriate for creating temporary files. (It has -security risks.) Better use @code{mkstemp} instead. - -@item tmpnam -This function is not appropriate for creating temporary files. (It has -security risks.) Better use @code{mkstemp} instead. - -@item towctrans -@itemx towlower -@itemx towupper -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item ungetc -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -@item ungetwc -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item unlink -Removing an open file is non-portable: On Unix this allows the programs that -have the file already open to continue working with it; the file's storage -is only freed when the no process has the file open any more. On Windows, -the attempt to remove an open file fails. - -@item usleep -According to POSIX, the @code{usleep} function may interfere with the program's -use of the @code{SIGALRM} signal. On Linux, it doesn't; on other platforms, -it may. - -@item utime -On some systems, @code{utime (file, NULL)} fails to set the file's timestamp -to the current time. - -@item utimes -This function is marked as ``legacy'' in POSIX. Better use @code{utime} -instead. - -@item va_arg -The second argument of @code{va_arg} must be a type that is invariant under -the ``default argument promotions'' (ISO C 99 6.5.2.2 paragraph 6). This -means that the following are not valid here: -@table @asis -@item @samp{float} -Use @samp{double} instead. -@item @samp{bool} -Use @samp{int} instead. -@item Integer types smaller than @samp{int}. -Use @samp{int} or @samp{unsigned int} instead. -@end table - -This is a portability problem because you don't know the width of some -abstract types like @code{uid_t}, @code{gid_t}, @code{mode_t}. So, instead of -@smallexample -mode = va_arg (ap, mode_t); -@end smallexample -you have to write -@smallexample -mode = (sizeof (mode_t) < sizeof (int) - ? va_arg (ap, int) - : va_arg (ap, mode_t)); -@end smallexample - -@item va_copy -Some platforms don't provide this macro. You can use __va_copy where -available instead, or otherwise an assignment or @code{memcpy} call. - -@item vfprintf -On NetBSD and Windows, this function doesn't support format directives that -access arguments in an arbitrary order, such as @code{"%2$s"}. The fix is to -include @file{<libintl.h>} from GNU gettext; it redefines this function so that -it is POSIX compliant. - -On Windows systems (excluding Cygwin), this function doesn't support -the @code{'} flag and the @code{hh}, @code{ll}, @code{j}, @code{t}, -@code{z} size specifiers. - -@item vfscanf -On Windows systems (excluding Cygwin), this function does not set @code{errno} -upon failure. - -On Windows, this function doesn't support the @code{hh}, @code{ll}, @code{j}, -@code{t}, @code{z} size specifiers. - -@item vprintf -@itemx vsnprintf -@itemx vsprintf -On NetBSD and Windows, these functions don't support format directives that -access arguments in an arbitrary order, such as @code{"%2$s"}. The fix is to -include @file{<libintl.h>} from GNU gettext; it redefines these functions so -that they are POSIX compliant. - -On Windows systems (excluding Cygwin), this function doesn't support -the @code{'} flag and the @code{hh}, @code{ll}, @code{j}, @code{t}, -@code{z} size specifiers. - -@item vscanf -@item vsscanf -On Windows systems (excluding Cygwin), these functions do not set @code{errno} -upon failure. - -On Windows, these functions don't support the @code{hh}, @code{ll}, @code{j}, -@code{t}, @code{z} size specifiers. - -@item vswprintf -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -On Windows, this function does not take a buffer size as second argument. - -@item waitid -As of 2005, no system is known on which @code{waitid} with flag @code{WNOWAIT} -works correctly. - -@item wcrtomb -@itemx wcscat -@itemx wcschr -@itemx wcscmp -@itemx wcscoll -@itemx wcscpy -@itemx wcscspn -@itemx wcsftime -@itemx wcslen -@itemx wcsncat -@itemx wcsncmp -@itemx wcsncpy -@itemx wcspbrk -@itemx wcsrchr -@itemx wcsrtombs -@itemx wcsspn -@itemx wcsstr -@itemx wcstod -@itemx wcstof -@itemx wcstoimax -@itemx wcstok -@itemx wcstol -@itemx wcstold -@itemx wcstoll -@itemx wcstombs -@itemx wcstoul -@itemx wcstoull -@itemx wcstoumax -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@item wcswcs -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -This function is marked as ``legacy'' in POSIX. Better use @code{wcsstr} -instead. - -@item wcswidth -@itemx wcsxfrm -@itemx wctob -@itemx wctomb -@itemx wctrans -@itemx wctype -@itemx wcwidth -@itemx wmemchr -@itemx wmemcmp -@itemx wmemcpy -@itemx wmemmove -@itemx wmemset -@itemx wprintf -@itemx wscanf -On Windows systems, @code{wchar_t} is a 16-bit type and therefore cannot -accommodate all Unicode characters. - -@end table