kc3-lang/gnulib/doc/posix-functions/readlinkat.texi

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• Hash : 8c9cfa07
  Author :
  Date : 2015-05-31T03:08:52
  

  readlinkat: avoid OS X 10.10 trailing slash bug
  
  * doc/posix-functions/readlink.texi: Mention that OS X 10.10
  has this bug.
  * doc/posix-functions/readlinkat.texi: Likewise.  Also mention
  that OS X 10.10 has this function.
  * lib/readlinkat.c (rpl_readlinkat): Handle the trailing slash bug,
  as done for readlink().
  * m4/readlinkat.m4 (gl_FUNC_READLINKAT): Check for the readlink()
  trailing slash bug, and assume readlinkat() has the same issue.
  Also fix a typo where $gl_cv_decl_readlink_works was tested,
  rather than the correct $gl_cv_decl_readlinkat_works.
  

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• doc/posix-functions/readlinkat.texi

• @node readlinkat
  @section @code{readlinkat}
  @findex readlinkat
  
  POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/readlinkat.html}
  
  Gnulib module: readlinkat
  
  Portability problems fixed by Gnulib:
  @itemize
  @item
  This function is missing on some platforms:
  glibc 2.3.6, Mac OS X < 10.10, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8,
  AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin 1.5.x, mingw, MSVC 9, Interix 3.5, BeOS.
  But the replacement function is not safe to be used in libraries and is not multithread-safe.
  @item
  Some platforms mistakenly succeed on @code{readlink("link/",buf,len)}:
  Mac OS X 10.10.
  @item
  On some platforms, @code{readlinkat} returns @code{int} instead of
  @code{ssize_t}:
  AIX 7.1.
  @item
  @end itemize
  
  Portability problems not fixed by Gnulib:
  @itemize
  @item
  This function always fails on platforms that don't support symlinks:
  mingw, MSVC 9.
  @item
  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}.
  @item
  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 @code{EINVAL}.
  @item
  Symlink contents do not always have a trailing null byte, and there is
  no indication if symlink contents were truncated if the return value
  matches the length.  Furthermore, AIX 5.1 and HP-UX 11 set
  @code{errno} to @code{ERANGE} rather than returning truncated
  contents, and Linux sets @code{errno} to @code{EINVAL} if the
  requested length is zero.  Use the gnulib module areadlink for
  improved ability to read symlink contents.
  @end itemize
  

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