X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=doc%2Fposix-functions%2Funlinkat.texi;h=cf334098a219aeb42758261b86cce54c15195d71;hb=a8f388076c6bc5ec6a9dd191ca703d23d9c22850;hp=9cb322a1e73fd7fc945f5bf39491c99adaa95df5;hpb=17f87c3231d8808b8e873126abf15e6e8b9a0e67;p=gnulib.git

diff --git a/doc/posix-functions/unlinkat.texi b/doc/posix-functions/unlinkat.texi
index 9cb322a1e..cf334098a 100644
--- a/doc/posix-functions/unlinkat.texi
+++ b/doc/posix-functions/unlinkat.texi
@@ -4,15 +4,48 @@
 
 POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/unlinkat.html}
 
-Gnulib module: ---
+Gnulib module: openat
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on some platforms:
+glibc 2.3.6, MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX
+5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Cygwin 1.5.x, mingw, Interix 3.5, BeOS.
+But the replacement function is not safe to be used in libraries and is not multithread-safe.
+@item
+Some systems mistakenly succeed on @code{unlinkat(fd,"file/",flag)}:
+GNU/Hurd, Solaris 9.
+@item
+Some platforms declare this function in @code{fcntl.h} instead of
+@code{unistd.h}:
+Cygwin 1.7.1.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
 @item
-This function is missing on some platforms:
-glibc 2.3.6, MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Cygwin, mingw, Interix 3.5, BeOS.
+When @code{unlinkat(fd,name,AT_REMOVEDIR)} fails because the specified
+directory is not empty, the @code{errno} value is system dependent.
+@item
+POSIX requires that @code{unlinkdir(fd,"link-to-empty/",AT_REMOVEDIR)}
+remove @file{empty} and leave @file{link-to-empty} as a dangling
+symlink.  This is counter-intuitive, so some systems fail with
+@code{ENOTDIR} instead:
+glibc
+@item
+Some systems allow a superuser to unlink directories, even though this
+can cause file system corruption.  The error given if a process is not
+permitted to unlink directories varies across implementations; it is
+not always the POSIX value of @code{EPERM}.  Meanwhile, if a process
+has the ability to unlink directories, POSIX requires that
+@code{unlinkat(fd,"symlink-to-dir/",0)} remove @file{dir} and leave
+@file{symlink-to-dir} dangling; this behavior is counter-intuitive.
+The gnulib module unlinkdir can help determine whether code must be
+cautious of unlinking directories.
+@item
+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.
 @end itemize